Tag: vaccination

Categories : General Interest VaccinesTags :

“Not Being Afraid to Speak out, it does get me into Trouble Quite Often,” Says Prof Shabir Madhi

On By ModernMedia
Professor Shabir Madhi of Wits University. Photo: supplied.

By Biénne Huisman

Amid the uncertainty of the early days of the COVID-19 pandemic, Professor Shabir Madhi often stood out for his clarity of thought in making sense of rapidly evolving scientific evidence. Biénne Huisman chatted to Madhi about vaccines, ongoing challenges with the Gauteng health department, and being outspoken about issues such as the war in Gaza.

Professor Shabir Madhi became known to many in South Africa for leading the charge in two of the first COVID-19 vaccine clinical trials conducted in Africa – those for the AstraZeneca and Novavax vaccines. At a time of much scientific uncertainty, he was often quoted in the press – gaining a reputation for keeping his cool and calling things as he saw them based on available evidence.

He spoke out against the politicisation of science and was a staunch advocate for access to vaccines, especially for older people at higher risk of severe illness and death. He wasn’t afraid to ruffle feathers, openly criticising government’s COVID-19 vaccine communication efforts and arguing that government should take vaccines to the people, rather than the other way around. He called for the ending of strict lockdowns, before many others did so. Reflecting on his reputation for not holding back on his beliefs, he admits to “having a short fuse, especially when people are talking nonsense – or what I consider to be entirely off the mark”.

What may be less obvious to the public, is that Madhi’s healthcare impact precedes COVID by decades.

Internationally respected for his research into paediatric infectious diseases, his work has helped to save the lives of hundreds of thousands of children and informed World Health Organization policy (WHO) – notably relating to the pneumococcal conjugate vaccine (to prevent pneumonia and meningitis) and the rotavirus vaccine (to prevent diarrhoeal disease in young children).

His work continues. Just last year a landmark study, led in South Africa by Madhi’s Vaccines and Infectious Diseases Analytics Research Unit at the University of the Witwatersrand (Wits), found that immunisation of pregnant women safely protected their unborn babies from respiratory syncytial virus (RSV). As Spotlight reported at the time, researchers estimate the vaccine can save thousands of young lives.

Speaking to Spotlight over Zoom from Wits in Johannesburg, where he is Dean of Health Sciences, Madhi relays his love of treating kids – who “most importantly, don’t lie, and who are the most vulnerable”.

“Accidental vaccinologist”

Madhi has been described as an “accidental vaccinologist”. Shrugging inside a navy suit, he says he never intended to become a physician, let alone a professor in vaccinology. At medical school at Wits, he nearly dropped out after a month.

As a child, growing up in Lenasia, Madhi wanted to become an engineer. But born to a mathematics teacher father and a stay at home mum, money was tight. His only opportunity to attend university presented itself via a bursary in medicine.

“I only really started to enjoy medicine once I specialised in paediatrics,” he says. “But more importantly, that’s when I realised the huge potential that existed in medicine to make a difference, particularly the potential for vaccines to make a big difference over a short period of time – not on an individual level, but at a community level. And that’s what really drove me into the space of research.”

While doing his peadiatric training at Chris Hani Baragwanath Academic Hospital (he obtained a master’s degree in paediatrics from Wits in 1998), it struck him that the leading causes of death among children were entirely preventable.

“Back then, close to 750 000 children were dying of measles globally; half of those deaths were happening in Africa, despite the vaccine for measles being available since the 1970s. South Africa was one of the countries with a poor public immunisation programme; up until 1992 South Africa didn’t have a public immunisation programme.”

In 2009, in a first on the African continent, pneumococcal and rotavirus vaccines were finally officially rolled out in South Africa.

“While I was training at Baragwanath, there was a ward just for children with gastroenteritis or diarrhoea,” he recalls. “But six months after we introduced the rotavirus vaccine in South Africa [in 2009], we shut down the diarrhoea ward at Baragwanath and probably every other diarrhoea ward in the country.”

Contributing internationally

Today Madhi’s CV is long. He sits on scores of scientific advisory committees, attending conferences and delivering talks around the world.

Since 2019, he has served on a global panel of experts convened by the WHO, the Strategic Advisory Group of Experts on Immunization (SAGE), of which he now is deputy chair. He also chairs the SAGE working group on polio.

“I’m really enjoying SAGE at the moment,” he says. “This is where I think I am making a meaningful contribution. It really is an eye opener to the different types of research that’s taking place globally; but also the type of challenges we face in terms of ensuring that children are adequately immunised.

“It’s great to be working on new vaccines, coming up with new vaccines; but that’s a meaningless exercise unless you can ensure that those vaccines are getting into the arms of children – because that is what saves lives. So yes, dealing with issues around implementation and advocacy.”

SAGE requires frequent trips to Geneva, where the WHO is based.

Our discussion turns to business travel – the amount required for a researcher to remain “relevant and competitive”. With typical candour, Madhi outlines challenges faced by researchers from the global south.

“I think coming from South Africa, coming from the African continent, it’s more of a challenge for researchers to establish themselves, for a number of reasons. Firstly to become known in the international space, you probably need to deliver so much more than what is expected from our northern hemisphere counterparts.

“Then in addition to the inconvenience of needing to travel so often, there are subtle things which people in the northern hemisphere don’t have to deal with. Needing to get visas and dealing with customs officials when entering countries.

“It can become an extremely unpleasant experience, and you really need to swallow your pride given what is blatant racism at times. For example, nowadays I refuse to fly through Germany because the customs office in Frankfurt is probably the worst I have encountered. All of a sudden, they would keep me and question me for both arrival, as well as departure…”

Local challenges

The discussion turns back to South Africa, and health challenges in his home province of Gauteng. Here also Madhi has tried to make a difference, but it hasn’t been plain sailing.

Commenting on a floundered memorandum of agreement (MOA) signed between Wits and the Gauteng Department of Health in June 2022, Madhi says: “The bottom line unfortunately; the Gauteng Department of Health simply doesn’t have stability of leadership. At the level of the MEC in particular; I mean since I’ve been dean, there’s been about four or five heads of department. And it becomes difficult to follow through with any of these programmes.”

Madhi adds that Wits university executives had worked on the memorandum for seven years. The agreement set out a plan to combine university and government resources in “academic health complexes” for enhanced service delivery. But the Department of Health put it on hold three months later, following a related Public Service Commission inquiry.

He explains: “They convened this big workshop, spending probably a mini fortune, to basically facilitate the establishment of an MOA, not just between Wits and the Department of Health, but between the Department of Health and many other academic hospitals in the province. Because of the intervention, the Department of Health indicated that they weren’t going to implement our MOA until that particular commission concluded their work. But since then, there’s been absolutely no report from that meeting.”

Not afraid to speak out

On social media, Madhi speaks out about atrocities being committed in Gaza.

To Spotlight, he says leadership holds no place for neutrality.

“As part of leadership, and I do consider myself a leader in the different roles that I play – either in my research unit or currently as university dean – you need to be prepared to take a stance. You can’t remain neutral on positions. You need to interrogate facts. And once having interrogated the facts, you need to reach a conclusion; then follow through with what is required, if there’s anything that needs to be implemented.”

Madhi says his leadership style was honed during childhood. “Not being afraid to speak out, it does get me into trouble quite often,” he says, laughing. “I think that’s just part of my upbringing, being an activist during apartheid in the Lenasia Youth League and other activist organisations. My upbringing was, when things are not what it’s meant to be, you speak out; you champion the right cause.”

These days Madhi lives in Northcliff with his wife, with whom he has two children. His favourite football team is Arsenal and a book he says he recently enjoyed was The Covenant of Water – a three generation family account set in India, by physician and author Abraham Verghese.

Republished from Spotlight under a Creative Commons licence.

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Categories : COVID Immune SystemTags :

COVID did not get Weaker – Our Immune Systems got Stronger, Large Scale Study Suggests

On By ModernMedia
Image by Fusion Medical on Unsplash

Researchers have shown that the reduced mortality from COVID is not necessarily due to the fact that later variants, such as Omicron, have been less severe. Rather, the reduced mortality seems to be due to several other factors, such as immunity from previous vaccinations and previous infections. The study is published in the latest issue of Lancet Regional Health Europe.

The researchers at Karolinska Institutet, together with partners in the EuCARE project, conducted a study using patient data from more than 38 500 hospitalised patients with COVID, from the start of the pandemic to October 2022. The data comes from hospitals in ten countries, including two outside Europe.

The data showed that in-hospital mortality decreased as the pandemic progressed, especially since Omicron became the dominant variant. However, when the researchers modelled the mortality rates for different variants (pre-Alpha, Alpha, Delta and Omicron) and took into account factors such as age, gender, comorbidity, vaccination status and time period, they saw far fewer differences and weaker associations. They also saw differences between age groups, highlighting the importance of conducting separate analyses for different age groups. 

“Overall, our findings suggest that the observed reduction in mortality during the pandemic is due to multiple factors such as immunity from vaccination and previous infections, and not necessarily tangible differences in inherent severity,” says Pontus Hedberg, first author of the study. 

Omicron variant no less severe 

Understanding the disease course and outcomes of patients hospitalised with COVID during the pandemic is important to guide clinical practice and to understand and plan future resource use for COVID. A particularly interesting finding is that the inherent severity of Omicron has not necessarily been significantly reduced, but that other factors are behind the reduction in mortality. 

“The fact that Omicron can cause severe disease was seen in Hong Kong, for example, where the population had low immunity from previous infections and low vaccination coverage. In Hong Kong there was a relatively high mortality from Omicron,” says Pontus Hedberg. 

Highlights the importance of protecting the elderly and those with underlying diseases

The main applications of the study results going forward are the continued need to protect the elderly and patients with other underlying disease from severe disease outcomes through vaccination against COVID, even though new virus variants may appear less virulent. The results are also important for understanding trends in mortality in hospitalised patients with COVID and thus planning for resource use in hospital care.

Larger multinational collaborative projects like this are of great value to increase the generalisability of studies and not least to promote international collaboration also for future pandemic or epidemic scenarios.

Source: Karolinska Institutet

Categories : COVID VaccinesTags :

A Universal Coronavirus Vaccine could Save Millions of Lives in a Future Pandemic

On By ModernMedia
Photo by Mika Baumeister on Unsplash

What if in the years prior to the COVID pandemic, scientists had developed a universal coronavirus vaccine, one that targets parts common to coronaviruses, offering some protection against all strains? Would it have been of help during the pandemic?

A new study suggests if such a vaccine were available at the start of the pandemic, it could have saved millions of lives, prevented suffering, and saved billions of dollars in direct medical and other costs until the strain-specific (ie, SARS-CoV-2) vaccine went through the entire development, testing, and emergency use authorisation process that lasted 10 months.

In this study, published in The Lancet’s eClinicalMedicine, researchers show that having a universal vaccine at the start of the pandemic would have had substantial health and economic benefits under almost all scenarios tested.

In order to determine the value of investing in developing and stockpiling a universal coronavirus vaccine, the team developed a computational model that simulated the entire US population, the introduction and spread of a novel coronavirus like SARS-CoV-2 in 2020 and the resulting health (eg, infections, hospitalisations) and economic (eg, direct medical costs, productivity losses) outcomes.

The experiments simulated what would happen if a universal coronavirus vaccine was available at the start of the COVID pandemic.

Vaccinating with a universal coronavirus vaccine as a standalone intervention (e.g., no face mask use or social distancing) was cost-saving even when its efficacy was as low as 10% and only 10% of the U.S. population received the vaccine.

For example, when a universal coronavirus vaccine has 10% efficacy, vaccinating a quarter of the U.S. population within two months of the start of the pandemic averts an average of 14.6 million infections and saves over $27 billion in direct medical costs.

Such low vaccine coverage at the start of the pandemic could occur if a vaccine were only made available to certain high-risk subpopulations (eg, 65 years and older, the immunocompromised, frontline workers), similar to the approach when mRNA vaccines became available in December 2020.

“COVID-19 was the third major and serious coronavirus epidemic or pandemic following SARS in 2002 and MERS in 2012, thus, we should anticipate a fourth coronavirus outbreak within the next decade or so,” says Peter J. Hotez, MD, PhD, dean of Baylor’s National School of Tropical Medicine and co-director of the Texas Children’s Hospital Center for Vaccine Development.

“A universal vaccine is cost-effective and cost-saving and a priority for advancement.”

A universal coronavirus vaccine was also shown to be highly cost-effective even if a more specific and more efficacious vaccine came to market.

For example, the study shows if it takes four months or longer for a strain-specific vaccine to reach the market, using a universal vaccine was still cost cost-saving.

In a scenario where a strain-specific vaccine has 90% efficacy but is unavailable for two months after the start of the pandemic, the results from the model show that vaccinating only 10% of the population with a universal vaccine that has 10% efficacy at the start of the pandemic can save over $2 billion in societal costs (eg, direct medical costs and productivity losses from absenteeism). Given the time required to develop a strain-specific vaccine during a pandemic to match circulating strains of the virus, this highlights the importance of having a universal vaccine readily available as a stopgap.

“Our study shows the importance of giving as many people as possible in a population at least some degree of immune protection as soon as possible,” explains Bruce Y. Lee, MD, MBA, executive director of PHICOR and professor at CUNY SPH.

“Having a universal vaccine developed, stockpiled, and ready to go in the event of a pandemic could be a game-changer even if a more specific vaccine could be developed three to four months later.”

Generally, results from the model found that a universal vaccine would end up saving money if the cost to get a person vaccinated (eg, cost of the vaccine itself, distribution, administration, storage, research, and development) is as high as $10 390 from a societal perspective.

Source: CUNY Graduate School of Public Health and Health Policy

Categories : Cancer VaccinesTags :

Turning Everyday Vaccines into Cancer Killers

On By ModernMedia
Photo by National Cancer Institute

A study in Frontiers in Immunology has demonstrated that, in animal models, a protein antigen from a childhood vaccine can be delivered into the cells of a malignant tumour to refocus the body’s immune system against the cancer, effectively halting it and preventing its recurrence.

Instead of using vaccines tailored with tumour-specific antigens to prime the immune system to attack a particular cancer, this method makes use of the immune system’s encounter with common vaccines. The bacteria-based intracellular delivering (ID) system uses a non-toxic form of Salmonella that releases a drug, in this case a vaccine antigen, after it’s inside a solid-tumour cancer cell.

“As an off-the-shelf immunotherapy, this bacterial system has the potential to be effective in a broad range of cancer patients,” writes senior author Neil Forbes, professor of chemical engineering, in the recently published article.

The research, carried out in Forbes’s lab, offers promise toward tackling difficult-to-treat cancers, including liver, metastatic breast and pancreatic tumours.

“The idea is that everybody is vaccinated with a whole bunch of things, and if you could take that immunisation and target it towards a cancer, you could use it to eliminate the cancer,” Forbes explains. “But cancers obviously aren’t going to display viral molecules on their surface. So the question was, could we take a molecule inside the cancer cell using Salmonella and then have the immune system attack that cancer cell as if it was an invading virus?”

To test their theory that this immune treatment could work, Forbes and team genetically engineered ID Salmonella to deliver ovalbumin (chicken egg protein) into the pancreatic tumour cells of mice that had been immunised with the ovalbumin ‘vaccine’. The researchers showed that the ovalbumin disperses throughout the cytoplasm of cells in both culture and tumours.

The ovalbumin then triggered an antigen-specific T-cell response in the cytoplasm that attacked the cancer cells. The therapy cleared 43% of established pancreatic tumours, increased survival and prevented tumour re-implantation, the paper states.

“We had complete cure in three out of seven of the pancreatic mice models,” Forbes says. “We’re really excited about that; it dramatically extended survival.”

The team then attempted to re-introduce pancreatic tumours in the immunised mice. The results were exceedingly positive. “None of the tumours grew, meaning that the mice had developed an immunity, not just to the ovalbumin but to the cancer itself,” Forbes says. “The immune system has learned that the tumour is an immunogenic. I’m doing further work to figure out how that’s actually happening.”

In preliminary research, the team previously showed that injecting the modified Salmonella into the bloodstream effectively treated liver tumours in mice. They advanced their findings with the current research on pancreatic tumours.

Before clinical trials can begin, the researchers will repeat the experiments on other animals and refine the ID Salmonella strain to ensure its safety for use in humans. Liver cancer would be the first target, followed by pancreatic cancer.

Source: University of Massachusetts Amherst

Categories : Immune System VaccinesTags :

Can People Accurately Assess the Strength of Their Immune Systems?

On By ModernMedia
Photo by Brittany Colette on Unsplash

People often say whether they feel like their immune system is ‘down’ – but could there be some truth to this? A recent study showed that when freshly vaccinated people self-assessed the strength of their immune response, their estimates correlated well to their measured antibody levels. They were even more accurate when their immune response was weak. The results were published in the journal Biological Psychology.

At the University of Konstanz, Stephanie psychologist Dimitroff researches the connection between our brain and our immune system. “Listen to your body,” she concludes from her study. “The field of medicine is moving towards greater patient orientation. Our findings support the idea that patients’ self-perceptions provide valuable clues about their state of health. Physicians should listen to them more.”

Communication between the immune and nervous systems

One part of our brain, the insula, receives information from the body and gives us a basic impression of its condition, which until now was assumed to be quite general in nature. Stephanie Dimitroff’s study now suggests that our brain can perceive the body’s condition more specifically than previously thought. Is it possible that our brain can assess the state of our immune system?

“Of course, our brain does not count antibodies. But our immune system is intrinsically connected to the central nervous system,” Dimitroff explains. “The immune system is regulated via this connection. And our brain also receives information from the immune system.”

This communication between the immune system and the central nervous system is key for our sense of well-being or illness. “It is important to know here: When we feel ill, for example, we have a cold, this feeling is caused quite significantly by the immune system’s communication with the central nervous system,” says Dimitroff. “The brain receives signals that something is wrong with the body and causes the feeling of illness as a result.”

The same flow of information between the immune and nervous systems can generally also take place when the body is not ill. This means it could be possible that this communication process gives us an impression of our immune system even when we are healthy. Stephanie Dimitroff’s study investigates whether this is actually the case.

Results of the study

The study looked at people who had received the COVID-19 vaccine. This group of participants was chosen because a particularly large number of people received the vaccine in the summer of 2021, when the study was conducted. 166 people between the ages of 18 and 59 participated in the study.

After vaccination, the participants in the study were able to assess surprisingly well how strongly their immune system was positioned to fight the respective illness. This was especially true for people who had developed only a few antibodies. In fact, 71% of participants who did not feel well protected after vaccination also had a below-average immune response. “Our most notable finding is that those who felt they had not produced high levels of antibodies after vaccination were often correct in their assessment.”

By contrast, participants who assessed their immune response as good were not always right. However, all of those who had a particularly strong immune response also reported feeling well protected.

Alternative interpretations

For Stephanie Dimitroff, however, it is still too early to draw any final conclusions. The psychologist is considering other possible causes, including the placebo effect. This is because communication between the brain and the immune system runs in both directions. The signals from our brain can therefore also influence our immune system. People who firmly believe in vaccination or are basically optimistic could thus actually develop a better immune defence (placebo effect) and also feel better protected. It is therefore possible that belief in the effectiveness of a vaccine is what improves its efficacy, and this could also explain the high accuracy of the self-assessments.

“Our results suggest that it is quite likely that people have a real ability to assess their own health. However, I cannot rule out that there is a combination of effects at play, including the placebo effect and/or feelings of optimism,” Dimitroff says. In her view, it would make sense to repeat the study in order to confirm the results and rule out alternative causes.

Source: University of Konstanz

Categories : Paediatrics Pain ManagementTags :

Ways to Reduce Kids’ Needle-related Fear and Pain

On By ModernMedia
Image of a syring for vaccination
Photo by Mika Baumeister on Unsplash

In the COVID era, when vaccinations are all the more important, new research published in the European Journal of Pain shows that children’s vaccination and needle fear can be reduced with a couple of different techniques used by nurses.

These techniques divide the children’s attention or redress their fears by framing the positive elements of their experience.

Working with children aged 8–12 years, the preliminary study found that two new nurse-led techniques show promise in reducing needle fear in primary-aged children:

  • Divided Attention – where a child’s attention and expectations are drawn away from the needle.
  • Positive Memory Reframing – where a child’s exaggerations about the distress and discomfort of needles are redressed through discussion about the positive elements of the experience so that the form more realistic memories of the event.

Dr Felicity Braithwaite, lead researcher of the study, said that helping children reduce fear and distress around vaccinations is a key area of research in the COVID era.

“For many children, undergoing a needle procedure can be painful and distressing,” Dr Braithwaite said.

“Negative experiences of vaccinations in childhood can often lead to medical avoidance and vaccine hesitancy into adulthood, which can have devastating consequences when it comes to outbreaks of preventable diseases.

“By investing more time into techniques to help children manage their fears about needles, we hope to change these outcomes and deliver better health outcomes for the next generation.”

The study involved 41 children and their parents, with participants randomised to one of four groups – usual care, divided attention, positive memory reframing, or a combination of the latter two interventions. Clinical outcomes were assessed at baseline, immediately post-vaccination and at two-weeks post-vaccination. 

The Divided Attention technique involved a one to two minute distraction game where a nurse tapped the child’s arm above and below the vaccination spot in a random order, with the child focussing their attention on guessing which spot was touched each time. This game takes advantage of the potential analgesic effects of distraction.

The Positive Memory Reframing technique involved talking to children about a past injection and emphasising positive aspects, such as how brave the child was and praising specific strategies they used to reduce their own distress, for example, deep breathing and looking away. The aim is to foster a sense of self-efficacy to help children better cope.

Both techniques were tested outside of clinical locations, such as in schools, to maximise their applicability in real-world settings.

Source: University of South Australia

Categories : Diseases, Syndromes and ConditionsTags :

Amid Measles Spike, WHO Warns of Outbreaks of Vaccine-preventable Diseases

On By ModernMedia
Syringe injection into the upper arm
Image source: NCI on Unsplash

An increase in measles cases in January and February 2022 is a worrying sign of a heightened risk for the spread of vaccine-preventable diseases and could trigger larger outbreaks, particularly of measles affecting millions of children in 2022, warn WHO and UNICEF.

The agencies warn that pandemic-related disruptions, widening vaccine access inequality, and the under-resourcing of routine immunisation are leaving too many children open to measles and other vaccine-preventable diseases.

The risk for large outbreaks has increased as communities relax social distancing practices and other anti-COVID measures. Additionally, the displacement of millions of people due to conflicts and crises including in Ukraine, Ethiopia, Somalia and Afghanistan, is causing disruptions in immunisation services, a lack of clean water and sanitation, and overcrowding, all of which increase the risk of vaccine-preventable disease outbreaks.

Almost 17 338 measles cases were reported worldwide in January and February 2022, compared to 9665 during the first two months of 2021. Measles is highly contagious, so cases tend to show up quickly when vaccinations decline. The agencies are concerned that outbreaks of measles could also forewarn outbreaks of other diseases that do not spread as rapidly.

Apart from its direct, sometimes lethal, effect on the body, the measles virus also weakens the immune system rendering a child more vulnerable for months after to other infectious diseases like pneumonia and diarrhoea.  Most cases occur in settings that have faced social and economic hardships due to COVID, conflict or other crises, and have chronically weak health system infrastructure and insecurity.

“Measles is more than a dangerous and potentially deadly disease. It is also an early indication that there are gaps in our global immunization coverage, gaps vulnerable children cannot afford,” said Catherine Russell, UNICEF Executive Director. “It is encouraging that people in many communities are beginning to feel protected enough from COVID to return to more social activities. But doing so in places where children are not receiving routine vaccination creates the perfect storm for the spread of a disease like measles.”  

In 2020, 23 million children missed out on basic childhood vaccines through routine health services, the highest number since 2009 and 3.7 million more than in 2019.

Top 5 countries with reported measles cases in the last 12 months, until April 2022 1

CountryReported Measles casesRate per million casesFirst dose measles coverage (%), 20192First dose measles coverage (%), 20203
Somalia90685544646
Yemen36291196768
Afghanistan3628916466
Nigeria12 341585454
Ethiopia3039266058

As of April 2022, the agencies report 21 large and disruptive measles outbreaks around the world in the last 12 months. Most of the measles cases were reported in Africa and the East Mediterranean region. The figures are likely higher as the pandemic has disrupted surveillance systems globally, with potential underreporting.

Countries with the largest measles outbreaks since the past year include Somalia, Yemen, Nigeria, Afghanistan and Ethiopia. Insufficient measles vaccine coverage is the major reason for outbreaks, wherever they occur.

“The COVID pandemic has interrupted immunisation services, health systems have been overwhelmed, and we are now seeing a resurgence of deadly diseases including measles. For many other diseases, the impact of these disruptions to immunisation services will be felt for decades to come,” said Dr Tedros Adhanom Ghebreyesus, Director-General of the World Health Organization. “Now is the moment to get essential immunisation back on track and launch catch-up campaigns so that everybody can have access to these life-saving vaccines.”

As of 1 April 2022, 57 vaccine-preventable disease campaigns in 43 countries that were scheduled to take place since the start of the pandemic are still postponed, impacting 203 million people, most of whom are children. Of these, 19 are measles campaigns, which put 73 million children at risk of measles due to missed vaccinations. In Ukraine, the measles catch-up campaign of 2019 was interrupted due to the COVID pandemic and thereafter due to the war. Routine and catch-up campaigns are needed wherever access is possible to help make sure there are not repeated outbreaks as in 2017–2019, when there were over 115 000 cases of measles and 41 deaths in the country – this was the highest incidence in Europe.

Coverage at or above 95% with 2 doses of the safe and effective measles vaccine can protect children against measles. However, COVID pandemic related disruptions have delayed the introduction of the second dose of the measles vaccine in many countries.

Source: World Health Organization

Categories : COVID Immune SystemTags :

Differences in Natural and Vaccine-induced COVID Immunity Revealed

On By ModernMedia
Source: Fusion Medical Animation on Unsplash

A new study recently published in Nature has found that immune protection resulting from COVID protection creates lasting effects in memory B cells.

Unlike circulating antibodies, which peak soon after vaccination or infection only to fade a few months later, memory B cells can remain to ward off severe disease for decades. They also evolve over time, learning to produce successively more potent ‘memory antibodies’ that are more effective at neutralising the virus and with better adaptation to variants.

Though vaccination instils higher levels of circulating antibodies than natural infection, the study suggests that not all memory B cells are created equal. While vaccination gives rise to memory B cells that evolve over a few weeks, natural infection births memory B cells that continue to evolve over several months, producing highly potent antibodies adept at eliminating even viral variants.

Though the findings suggest an advantage from natural infection over vaccination, this does not outweigh the dangers of illness and death from COVID, the researchers warn.

“While a natural infection may induce maturation of antibodies with broader activity than a vaccine does – a natural infection can also kill you,” explained Professor Michel C. Nussenzweig, head of Rockefeller’s Laboratory of Molecular Immunology. “A vaccine won’t do that and, in fact, protects against the risk of serious illness or death from infection.”

When any virus enters the body, immune cells immediately release circulating antibodies, which decay at variable rates depending on the vaccine or infection. They may confer protection for months or years but then dwindle in number, allowing possible reinfection.

Long term protection is provided by memory B cells that produce memory antibodies. Studies suggest that memory B cells for smallpox last at least 60 years after vaccination; those for Spanish flu, nearly a century. And while memory B cells don’t necessarily block reinfection, they can prevent severe disease.

Recent studies have suggested that within five months of receiving a vaccine or recovering from a natural infection, some no longer retain sufficient circulating antibodies to keep the novel coronavirus at bay, but memory B cells remain vigilant. Until now, however, scientists did not know whether the vaccines could be expected to provide the sort of robust memory B cell response seen after natural infection.

Prof Nussenzweig and colleagues resolved to tease out any differences in memory B cell evolution by comparing blood samples from convalescent COVID patients to those from never-infected mRNA-vaccinated individuals.

Vaccination and natural infection elicited similar numbers of memory B cells, which rapidly evolved between the first and second dose of the Pfizer and Moderna vaccines, producing increasingly potent memory antibodies. But after two months, progress stalled. The memory B cells were present in large numbers and expressed potent antibodies, but the antibodies were not getting any stronger. Also, although some of these antibodies were able to neutralize Delta and other variants, there was no overall improvement in breadth.

The researchers found that in convalescent patients, however, memory B cells continued to evolve and improve up to one year after infection. With every memory B cell update, more potent and more broadly neutralising memory antibodies were coming out.

There are several potential reasons that memory B cells produced by natural infection might be expected to outperform those produced by mRNA vaccines, the researchers said.

It is possible that the body responds differently to viruses that enter through the respiratory tract than those that are injected. Or perhaps an intact virus goads the immune system in a way the vaccines’ spike protein antigens simply cannot. It may also be possible that the virus persists in the naturally infected for weeks, giving the body more time to mount a robust response. The vaccine, on the other hand, is flushed out of the body mere days after triggering the desired immune response.

Memory B cells appear to undergo limited bouts of evolution in response to mRNA vaccines, a finding which may have significant implications for booster shots. A booster with the current mRNA vaccine would likely stimulate memory cells to produce antibodies strongly protective against the original virus and somewhat less so against the variants, Prof Nussenzweig said.

“When to administer the booster depends on the object of boosting,” he said. “If the goal is to prevent infection, then boosting will need to be done after 6 to 18 months depending on the immune status of the individual. If the goal is to prevent serious disease, boosting may not be necessary for years.”

Source: Rockefeller University

Categories : VaccinesTags :

Attenuated Virus Confers Broader Flu Protection

On By ModernMedia
Source: Pixabay CC0

A mouse study using both attenuated and inactivated forms of influenza has helped explain why people vaccinated with the inactivated virus still occasionally end up contracting the illness. The finding should help researchers develop vaccines that offer broad protection against viruses.

Influenza is a major global health burden, with the World Health Organization estimating that it causes one billion cases annually. Each year, vaccines are developed that offer some protection against infection. But the influenza virus is a moving target that is constantly mutating, and so vaccines can lose their effectiveness as a season progresses.

Influenza vaccines commonly come in two forms: inactivated vaccines (including component vaccines) and live attenuated vaccines. Live vaccines confer broader protection against variants than inactivated vaccines, but side effects such as fevers and headaches are more common. A result they have yet to be approved in some countries. Live vaccines induce the production of broadly reactive antibodies, but until now, scientists didn’t know why.

In a recent study, Masato Kubo of the RIKEN Center for Integrative Medical Sciences and his co-workers have discovered two processes that live vaccines induce in mice that together account for their broader protection.

They found that, like the virus itself, the live vaccine virus causes the virus to replicate deep in the lungs, which in turn induces a structural change in the virus haemagglutinin, a mushroom-shaped protein on the surface of the virus involved in infecting cells. This structural change exposes previously hidden regions of antigens that the immune system can recognise.

Next, germinal cells are activated by interleukin 4 (IL-4), a cytokine heavily involved in regulating antibody production. IL-4 is derived from special T cells known as follicular helper T cells. This activation causes a minor population of B cells to proliferate and it is these B cells that are responsible for generating broadly protective antibodies.

The role of IL-4 in inducing the broad immune response came as a surprise. “Until now there had been no direct evidence to show the importance of IL-4,” says Kubo. “That was one of the surprises of this study for me.”

“We believe both processes are needed for generating broadly active antibodies: viral duplication in the lungs and expansion of the minor population of B cells,” says Kubo. “These two processes mostly likely occur when a person is infected by the influenza virus itself.”

The team now plans to see if there are similar mechanisms for other viruses such as SARS-CoV-2.

Source: RIKEN

Categories : Injury & Trauma VaccinesTags :

The Nagging Pain of Vaccination Shoulder Injuries

On By ModernMedia
Image source: NCI on Unsplash

Shoulder injury related to vaccine administration (SIRVA) has been documented long before COVID, and most commonly reported after influenza vaccination. The cause is often due to poor administration. 

However, the medical community cautions that currently it’s more of a medicolegal determination rather than a distinct diagnosis. The condition is also plagued by the lack of a solid evidence base, and causality is difficult to pin down.

However, most physicians that MedPage Today interviewed put shoulder injury down to improper injection technique, and that these problems should be taken seriously and treated appropriately. One recent overview noted that SIRVA is a “rare yet increasingly recognised complication of immunisation.”

“We’re certainly not seeing a pandemic of SIRVA” from COVID vaccines, said Dr DJ Kennedy, chair of physical medicine & rehabilitation at Vanderbilt University Medical Center. “It’s really rare and the literature to date is mostly case reports. But I do think it’s possible, absolutely” for vaccine-related shoulder injury to occur.

Dr Laura Keeling, orthopedic surgeon at MedStar Georgetown University Hospital, told MedPage Today that part of the reason SIRVA remains in the medicolegal realm is that it’s “more of a constellation of symptoms and findings” as opposed to a specific diagnosis.

Symptoms can vary depending on where the stray shot landed, resulting in various manifestations such as bursitis, tendonitis, or adhesive capsulitis (aka ‘frozen shoulder’).

Generally, it’s characterised as a “constellation of shoulder pain and reduced range of motion that occurs within 48 hours of vaccination and does not resolve within 1 week,” according to a recent paper co-authored by Dr Keeling. It’s also different from typical post-injection soreness, as the pain is more severe and it can impact mobility and function.

Generally, treatments include anti-inflammatory drugs, corticosteroid injections, and physical therapy. Occasionally surgery is necessary to treat an underlying pathology such as an exacerbated rotator cuff injury. Patients with SIRVA often land in their GP’s office first, and then may be referred to a specialist such as a physiatrist or an orthopedic surgeon.

“It’s the patients who have persistent symptoms who are referred to orthopedic surgeons,” Dr Keeling said. “If physical therapy and injection don’t work, then primary care refers to us.”

Physical medicine & rehabilitation physicians, or physiatrists, also play a large role in treating SIRVA.

“We treat based on a full evaluation including history and physical findings, and imaging if needed,” Dr Kennedy said. “Then we develop a comprehensive rehabilitation plan … that usually involves doing range of motion and strengthening exercises on a daily basis.”

Scott Noren, DDS, an oral surgeon in Ithaca, New York, said after his second COVID shot in early February, he developed shoulder pain: “It went in pretty deep and pretty high,” he told MedPage Today.

An MRI revealed fluid collecting in his joint, as well as adhesive capsulitis, he said. Physical therapy helped improve his range of motion to an extent, but he has lingering pain. It’s difficult to take x-rays and do long procedures as an oral surgeon: “I have pretty good pain even with just normal function now,” he said.

Source: MedPage Today