Tag: flu vaccine

Metabolic Health before Flu Vaccination Determines Its Effectiveness

A four-week healthy diet improved the effectiveness of a flu vaccine given to obese mice

Photo by Gustavo Fring on Pexels

Scientists at St. Jude Children’s Research Hospital have shown that improving metabolic health in obese mice before vaccination, but not after, protects against influenza virus.

Metabolic health (normal blood pressure, blood sugar and cholesterol levels, among other factors) influences the effectiveness of influenza vaccinations. Vaccination is known to be less effective in people with obesity compared to those with a healthier body mass index (BMI), but St. Jude Children’s Research Hospital scientists have found that the difference is attributable not to obesity itself, but rather metabolic dysfunction. In a study published in Nature Microbiology, the researchers found that switching obese mice to a healthy diet before flu vaccination, but not after, completely protected the models from a lethal dose of flu, despite BMI.

“We found that the vaccines worked effectively if at the time of vaccination an animal is metabolically healthy,” said corresponding author Stacey Schultz-Cherry, PhD, St. Jude Department of Host-Microbe Interactions and Center of Excellence for Influenza Research and Response co-director. “And the opposite was also true: regardless of what the mice looked like on the outside, if they had metabolic dysfunction, the vaccines did not work as well.”

Prior research has shown that 100% of obese mice succumbed to influenza after exposure, even after vaccination. Contrary to the scientists’ original expectations, when mice who were vaccinated while obese returned to a healthy weight, outcomes did not improve. These now outwardly healthy mice still all succumbed to disease when exposed to the real virus. Only switching to a healthy diet four weeks before vaccination improved survival, with drastic effect, despite high BMI.

“We were excited to see this effect because mice with obesity are so susceptible to severe disease and succumbing to the infection,” Schultz-Cherry said. “Getting 100% survival with the vaccine where we had only seen 0% survival was impressive.” The improved survival suggests the researchers have discovered a greater underlying principle determining influenza vaccine efficacy.

Metabolic dysfunction hinders the immune system

While studying how metabolic function influences influenza vaccine responses, the scientists found that poor metabolic health causes immune system dysfunction. T cells, the primary immune cells involved in anti-viral responses, failed to act in animals that had been in an unhealthy metabolic state at the time of vaccination, even during later viral exposure. Even when the animals ate a healthy diet after vaccination and maintained a normal BMI, the anti-flu T cells were “frozen” in that dysfunctional state.

However, a healthy diet before vaccination improved T-cell function, which resulted in a robust anti-flu response during later exposure.

“The T cells were better able to do their job in the metabolically healthy mice at the time of vaccination,” Schultz-Cherry said. “It wasn’t a matter of the numbers of them or the types of them. It was their functional activity. There were plenty of them in the lungs, not working. The healthy diet switched them from not working to functioning properly, but only if the switch occurred before vaccination.”

The earlier healthy diet also improved inflammation. Pro-inflammatory cytokines are upregulated in obese animals. Schultz-Cherry’s team found that models also returned to a lower basal cytokine level when switched to a healthy diet before vaccination.

“A healthy diet lowered some of the systemic meta-inflammation in these animals, and they regained some of the epithelial innate immune responses,” said Schultz-Cherry. “We started seeing better signalling of things like interferons, which we know is problematic in obesity and in general saw the immune system starting to function the way that it should.”

Improving metabolic health may improve influenza vaccine effectiveness

“What we found and are emphasising is that it’s not the phenotype of obesity that matters; it’s really about metabolic health,” Schultz-Cherry said. “It’s metabolic health at that moment of vaccination that really makes a difference.”

The study was restricted to mice, but it does open research opportunities to improve influenza vaccine efficacy in humans. The findings suggest methods of improving metabolic health may also improve subsequent influenza vaccinations. Given the recent introduction of metabolic improvement drugs, especially glucagon-like peptide 1 (GLP-1) agonists, there may be potential for a cooperative effect.

“We don’t know for sure, but if the outcome of using GLP-1 drugs is weight loss and improved metabolic health, we would hypothesise that it will help,” Schultz-Cherry said. “But we do know that we can do better protecting our vulnerable populations, and this study is a start for understanding how.”

Source: St. Jude Children’s Research Hospital

Just Ask: Many Patients in the ED are Open to Flu Vaccination

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Simply asking patients to get the flu vaccine, and combining it with helpful video and print messages, is enough to persuade many who visit emergency departments to roll up their sleeves, according to a new study published in NEJM Evidence.

Researchers led by UC San Francisco found a 32% vaccine uptake in patients who were asked if they’d be interested in getting the flu shot and told their health providers would be informed.

They saw a 41% uptake for those who were asked about receiving a flu shot and received a pamphlet, watched a three-minute video of a physician with a similar ethnic background discussing the vaccine and were told about the benefits of the vaccine.

The researchers say this type of systematic approach could lead to more underserved people receiving vaccines, especially those whose primary health care occurs in emergency departments.

Flu can be fatal

Annual mortality rates from flu are typically in the tens of thousands in the U.S., especially when combined with pneumonia – but vaccination is particularly low among underserved populations and those whose primary care occurs in emergency departments.

Such patients often face general vaccine hesitancy or a lack of opportunities for the flu shot.

“This research arose from our desire to address the health disparities that we see every day in our emergency department, especially among homeless persons, the uninsured and immigrant populations,” said first author, Robert M. Rodriguez, MD, a professor of Emergency Medicine with the UCSF School of Medicine.

The researchers designed the clinical trial to span a single flu season between October 2022 and February 2023.

Investigators in the study created flu vaccine messaging – including a brief video, flyer and a scripted health provider question, “Would you be willing to accept the influenza vaccine?” – and assessed their effectiveness among nearly 800 patients in five cities: San Francisco, Houston, Philadelphia, Seattle and Durham, North Carolina.

The median age was 46, and more than half the participants in the trial were Black or Latino, 16 % lacked health insurance, nearly a third had no primary care and 9% were homeless or living in severely inadequate housing. These demographic characteristics are similar to patient populations often served by urban emergency departments.

“Overall, our study adds to the growing body of knowledge showing that a number of important public health interventions can and should be delivered to underserved populations in emergency departments,” said Rodriguez, whose previous research has found the effectiveness of delivering similar COVID-19 vaccine messaging to emergency department patients.

Source: University of California – San Francisco

Children’s Birthdays Reveal the Best Month to Give Flu Shots

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In the northern hemisphere, children born in October are most likely to be vaccinated for the flu in October – and are least likely to be diagnosed with influenza, according to results of the first large-scale study of optimal timing for the flu shot.

The study, by researchers from the Department of Health Care Policy in the Blavatnik Institute at Harvard Medical School, amplifies public health guidance that encourages getting flu vaccinations in October for those in the northern hemisphere. The findings appear in the BMJ.

“There are a lot of variables when it comes to the timing and severity of flu season or a person’s risk of getting sick, and many of those are out of our control,” said Anupam Jena, the Joseph P. Newhouse Professor of Health Care Policy at HMS, physician at Massachusetts General Hospital, and senior author of the study. Christopher Worsham, HMS assistant professor of medicine and critical care physician at Mass General, led the study.

“One thing we have some control over is the timing of the shot,” Jena said, “and it looks like October is indeed the best month for kids to get vaccinated against the flu.”

In January the U.S. Centers for Disease Control and Prevention reported at least 150,000 hospitalizations and 9,400 deaths due to flu as of the time of the report and noted that high demand for hospital care for influenza has contributed to strained hospital capacity in some parts of the country. Over the past decade in the U.S., between one and 199 children have died of influenza each flu season. Across the years, most children who die are not fully vaccinated against the flu.

Part of the reason the timing of the shot is tricky is the way the immune system responds to a vaccine. If a person gets the shot too early, their immunity may fade by the time flu season peaks. If they wait too long, their body may not have time to build immunity strong enough to protect against the peak level of infections.

How soon is too soon, and how late is too late?

While public health recommendations in the U.S. have long promoted September and October flu shots, there has never been a randomised clinical trial to test the best timing, nor a large-scale effort to see how likely people who get vaccinated in other months are to get sick, Jena said.

When Jena was at a late summer meeting in 2022, he mentioned that his arm was sore from getting his flu shot. A colleague asked whether he was concerned about his immunity waning before flu season.

“It hadn’t occurred to me to check if one month or the other might make a big difference,” Jena said. “When we looked at the science, we were surprised that no one had ever looked at the question in a big population.”

Organising a clinical trial would require a lot of time and resources to coordinate the random distribution of flu jabs across hundreds or thousands of people.

But Jena, Worsham, and study co-author Charles Bray, HMS research assistant in health care policy, had a good idea where they could find an already randomized study population.

The surprising link between birth dates and childhood flu vaccination

In prior research reported in the New England Journal of Medicine in 2020, Jena and Worsham documented the way birth month determines how likely it is that children get the flu shot at all.

Young children in the U.S. tend to get their yearly checkup around their birthday, and it’s also when they get most of their vaccines. Children with spring and summer birthdays often don’t get the flu shot because it’s not available when they go for their annual visit, and many parents don’t make an extra trip for it.

The NEJM research was meant to highlight the importance of promoting the flu vaccine in the fall for children with birthday months that make it less likely that they will get the vaccine. Jena and Worsham realized they could also leverage this quirk of health care to study a ready-made distribution of children who get checkups – and flu shots – across all the months when the vaccine is commonly available.

Randomised by birthday

Studying children who got a flu shot in their birth month minimised certain factors related to the risk of infection that would have made it harder to measure the true impact of the timing of the shot.

For instance, families who proactively sought out shots in a non-birthday month might have done so because the child had a higher risk of catching the flu or because family members were more cautious and more likely to take actions that would protect them from the flu, such as handwashing and disinfecting.

For the BMJ study, Jena, Worsham, and Bray analysed the anonymised commercial health insurance records of more than 800 000 children in the U.S. from 2 to 5 years old who received influenza vaccines from 2011 to 2018.

The analysis showed that children born in October had the lowest rate of influenza diagnosis. For example, 2.7% of children born and vaccinated in October were diagnosed with the flu that season, compared to 3% of those born and vaccinated in August or January, 2.9% of those born and vaccinated in September or December, and 2.8% of those born and vaccinated in November.

The findings suggest that U.S. public health interventions focused on vaccination of young children in October may yield the best protection in typical flu seasons, the authors said.

“This study can help people pinpoint the best time to get flu vaccines for their children – especially the ones who weren’t born in October,” Worsham said.

“We’ve had several rough winters in a row for respiratory viruses, between COVID-19, RSV, and the flu,” Worsham said. “We need all the help we can get to keep people safe from these diseases.”

Source: Harvard Medical School

One Step Close to a Universal Flu Vaccine

Syringe withdrawing from vaccine vial
Photo by Mufid Majnun

A new universal flu vaccine protects against diverse variants of both influenza A and B viruses in mice, according to a new study published in the journal PLOS Pathogens.

The researchers designed a single, universal influenza vaccine candidate with key cross-protective, less variable parts of the influenza A and B viruses: multi-neuraminidase protein subtypes known to be major antiviral drug targets and the universally conserved M2 ectodomain protein.

The researchers, from the Institute for Biomedical Sciences at Georgia State University, report that mice vaccinated with an immune stimulating virus-like particle displaying multiple neuraminidase subtypes and conserved M2 portions of antigens were protected against influenza A seasonal variants and pandemic potential viruses (H1N1, H5N1, H3N2, H9N2 and H7N9) and influenza B (Yamagata and Victoria lineage) viruses containing substantial antigenic variations.

Viral variants emerge when flu pathogens change their major surface haemagglutinin protein that binds to host receptor molecules. Continuous mutational changes in the flu haemagglutinin proteins result in immune escape and sever disease.

Current influenza vaccines are based on strain-specific immunity to haemagglutinin, a highly variable target of immune protection. The effectiveness of the seasonal vaccine is unpredictable and could be below 20% because of continuous changes in haemagglutinin proteins. Influenza therefore remains a significant risk to human health worldwide.

“We developed a single, universal vaccine entity that induced immunity to conserved M2 ectodomain and multi subtype neuraminidase proteins and was found to be effective in conferring broad cross protection against antigenically diverse influenza A and B viruses in young and aged mice,” said Professor Sang-Moo Kang, senior author of the study. “This study provides impactful insight into developing a universal influenza vaccine inducing broad immunity against both flu A and B variants in young and aged populations.”

This study supports a novel strategy for creating a universal vaccine against influenza A and B viruses. A single construct displaying multiple cross protective proteins has the capacity to induce immunity to M2 and multi-subtype neuraminidase proteins of influenza A and B viruses, as well as offer broad cross protection against sickness and mortality under lethal flu virus challenges in mice, according to the study.

Vaccinating mice with this universal vaccine candidate induced broad neuraminidase inhibition, M2 ectodomain specific antibodies and T cell immune responses. Comparable cross protection was induced in aged mice.

The study warrants further testing of this unique, universal va ccine candidate in ferrets, which have similar respiratory tracts to humans.

Source: Georgia State University

New Universal Flu Vaccine Offers Broad Protection, Study Finds

Source: Pixabay CC0

By focusing on key parts which remain stable over time, scientists have created a universal flu vaccine that offers broad cross protection against different strains and subtypes of influenza A viruses in both young and old populations, according to a new study reported in npj Vaccines.

The researchers developed the universal flu vaccine by genetically linking two highly conserved portions of the virus: the extracellular domain of matrix 2 (M2e) and the stalk protein found in influenza A H3N2 viruses. The findings show that vaccinating against M2e-stalk protein induced broad protection against different influenza virus strains and subtypes by universal vaccine-mediated immunity in adult and aged mice.

Developing effective influenza vaccines has been a challenge because the head portion of the influenza virus is constantly mutating. When comparing the H1N1 and H3N2 influenza A viruses, particular challenges exist in H3N2 subtypes because of stalk mutations in circulating strains and the unstable structure of stalk proteins for H3N2 viruses. These drawbacks have been difficult to overcome in developing effective H3 stalk-based vaccines.

In the past decade, vaccine effectiveness against H3N2 hovered around 33%, and during the 2014–2015 flu season, it dropped to 6%. New mutations of H3N2 variants emerged with increased virulence. Also, the outbreak of H7N9, another influenza A subtype, caused concern for potential pandemics. Therefore, developing an effective vaccine to protect against these viruses is a high priority.

“The M2e-stalk protein, for the first time, could be easily produced in bacterial cell cultures at high yields and was found to confer protection against heterologous and heterosubtypic cross-group subtype viruses (H1N1, H5N1, H9N2, H3N2 and H7N9) at similar levels in adult and aged mice,” said Dr Sang-Moo Kang, senior author of the study and a professor in the Institute for Biomedical Sciences at Georgia State. “These results provide evidence that M2e-stalk genetic fusion proteins can be produced in a large scale at low cost and developed as a universal influenza A virus vaccine candidate for young and aged populations.”

The study found this novel M2e-stalk protein vaccine induced M2e and stalk-specific Immunoglobulin G (IgG) antibodies that recognised antigenically diverse influenza viral antigens on virus particles and on the infected cell surface. The vaccine also stimulated protective cellular T cell immunity and effective lung influenza viral clearance in mice.

Source: Georgia State University

Flu Jab May Protect Against Developing Alzheimer’s

Old man
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In a study with nearly 2 million older adults, those who received at least one influenza vaccine were 40% less likely than their non-vaccinated peers to develop Alzheimer’s disease over four years of follow-up, according to a new study from UTHealth Houston.

An early online version of the paper detailing the findings is available in advance of its publication in the Journal of Alzheimer’s Disease in August.

“We found that flu vaccination in older adults reduces the risk of developing Alzheimer’s disease for several years. The strength of this protective effect increased with the number of years that a person received an annual flu vaccine – in other words, the rate of developing Alzheimer’s was lowest among those who consistently received the flu vaccine every year,” said first author Avram S. Bukhbinder, MD. “Future research should assess whether flu vaccination is also associated with the rate of symptom progression in patients who already have Alzheimer’s dementia.”

The study comes two years after UTHealth Houston researchers found a possible link between the flu vaccine and reduced risk of Alzheimer’s disease. This new study analysed a much larger sample than previous research, including 935 887 flu-vaccinated patients and 935 887 non-vaccinated patients.

During four-year follow-up appointments, about 5.1% of flu-vaccinated patients were found to have developed Alzheimer’s disease. Meanwhile, 8.5% of non-vaccinated patients had developed Alzheimer’s disease during follow-up.

These results underscore the strong protective effect of the flu vaccine against Alzheimer’s disease, according to Bukhbinder and Schulz. However, the underlying mechanisms behind this process require further study.

“Since there is evidence that several vaccines may protect from Alzheimer’s disease, we are thinking that it isn’t a specific effect of the flu vaccine,” said Professor Paul. E. Schulz, MD, senior author of the study. “Instead, we believe that the immune system is complex, and some alterations, such as pneumonia, may activate it in a way that makes Alzheimer’s disease worse. But other things that activate the immune system may do so in a different way – one that protects from Alzheimer’s disease. Clearly, we have more to learn about how the immune system worsens or improves outcomes in this disease.”

Past research has uncovered a decreased risk of dementia associated with prior exposure to various adulthood vaccinations, including those for tetanus, polio, and herpes, in addition to the flu vaccine and others.

Additionally, as more time passes since the introduction of the COVID vaccine and longer follow-up data becomes available, Dr Bukhbinder said it seeing if there is a similar link between COVID vaccination and the risk of Alzheimer’s disease.

Source: The University of Texas Health Science Center at Houston

Did a Flu Vaccine Reduce Severe COVID Risk by 89%?

Vaccine injection
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In a study of more than 30 000 health-care workers in Qatar, those who got a flu jab were 89% less likely to develop severe COVID over the next few months.

The study, which is published in Nature, was conducted in late 2020, before COVID vaccines were rolled out. Its findings align with previous work suggesting that ramping up the immune system using influenza vaccines and other jabs could help the body to fend off the coronavirus SARS-CoV-2.

In the early months of the pandemic, there was great interest as to whether existing vaccines could confer some protection against SARS-CoV-2. But collecting strong evidence for such an effect is difficult, because people who sought out vaccination for other diseases could also make lifestyle choices that reduce the odds of catching COVID.

To reduce this ‘healthy-user effect’, a team led by Laith Jamal Abu-Raddad, an infectious-disease epidemiologist at Weill Cornell Medicine–Qatar in Doha, analysed the health records of 30 774 medical workers in the country. There is probably less variation in health-related behaviour among such workers than in the general population, reducing (but not eliminating) bias, Abu-Raddad said.

The researchers tracked 518 workers who tested positive for SARS-CoV-2 and matched them to more than 2000 study participants who had tested negative for the virus. Those who had received an influenza vaccine that season were 30% less likely to test positive for SARS-CoV-2, and 89% less likely to develop severe COVID, compared with workers who had not (although the number of severe cases was small in both groups). The study was posted on the medRxiv preprint server on 10 May.

Günther Fink, an epidemiologist at the University of Basel in Switzerland, said that the Qatar analysis makes it less likely that other studies reporting the same link were a fluke. His team reported that flu vaccines were associated with lower mortality in hospitalised COVID patients in Brazil.

“This is an important piece of evidence,” says Mihai Netea, an infectious-disease specialist at Radboud University Medical Center in Nijmegen, the Netherlands. The observation that influenza vaccines are linked to a reduction in not just SARS-CoV-2 infections, but also disease severity, strongly suggests that the protection is genuine, he adds.

How long this protection lasts is unclear. Among those in the Qatar study who had the flu jab and later contracted COVID, Abu-Raddad’s team recorded SARS-CoV-2 infections occurring, on average, about six weeks after vaccination. “I don’t expect to see this effect lasting long at all,” he says. Netea guesses that the benefits last for between six months and two years.

Exactly why flu vaccines, which are inactivated viruses, would also protect against COVID is unclear. Vaccines teach the immune system about specific pathogens, but they also stimulate broad-acting antiviral defences, said Netea, who has found signs of such responses in flu-vaccine recipients.

Netea’s team is also working to better quantify the benefits of vaccines targeting influenza and other diseases against COVID. His team has launched a randomised, placebo-controlled trial in Brazil that will test whether influenza and measles–mumps–rubella vaccines can protect against COVID, fully excluding the healthy-user effect.

Knowing that vaccines for flu and other diseases can offer protection against COVID, even if only partial and for a limited period, could limit the damage caused by a future pandemic before a vaccine for that disease is developed, Netea argues. “If you have something in the beginning, you could save millions of lives.”

Source: Nature

In Flu Season, Vaccine Reduces Cardiovascular Events in Heart Failure

Woman sneezing
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A randomised controlled trial showed that people with heart failure receiving an annual flu shot had lower rates of pneumonia and hospitalisation on a year-round basis and a reduction in major cardiovascular events during peak flu season – but not year-round.

The study, presented at the American College of Cardiology’s 71st Annual Scientific Session, is the first randomised controlled trial to assess the benefits of the flu vaccine in people with heart failure, who face a high risk of cardiovascular events. It was conducted in countries across Asia, Africa and the Middle East where getting a flu shot is not commonplace.

Lead author Mark Loeb, MD, said: “Although our prespecified endpoints were not significant, our data suggest that there’s a clinical benefit [to getting a flu shot] given the clear reduction in pneumonia, moderate reduction in hospitalisation and reduction in vascular events and deaths during periods of peak influenza. When taken together with previous trials and observational studies, the collective data demonstrate there is a substantial benefit to receiving a flu vaccine for people with heart failure.”

Heart failure is a condition in which the heart becomes too weak or stiff to pump blood effectively. Previous studies have shown that people with heart disease or cardiovascular risk factors face an elevated risk of complications when they contract influenza, but there has been a lack of evidence on whether flu vaccines can help to mitigate this risk specifically in people with heart failure.

The trial enrolled 5129 patients with heart failure in 10 countries where flu vaccines are not common. Participants did not routinely get flu shots and had previously received a flu shot no more than once during the three years preceding the trial. Participants were randomised to receive a flu shot or a placebo annually for up to three years, though they could still get a flu shot outside of the trial. Researchers tracked health outcomes for a median of 2.9 years. The trial’s primary endpoint was a composite of death from cardiovascular causes, non-fatal heart attack or non-fatal stroke. Its co-primary endpoint included a composite of any of these events plus hospitalisation for heart failure.

Overall, the composite primary endpoint occurred in 691 participants and 1470 experienced the composite co-primary endpoint. When analysed on a year-round basis there was no significant difference in the rates of these events between those who had received a flu vaccine and those who had not.

Separate analyses of hospitalisation, pneumonia and other respiratory outcomes however found that rates of pneumonia were 42% lower and hospitalisations were down 15% among those who received a flu shot.

The flu vaccine arm showed a significant reduction in the first primary endpoint, as well as reductions in all-cause death and cardiovascular death, when the analysis was limited to periods of peak influenza circulation. When influenza circulation was low, no significant difference was seen.

The researchers accounted for the differences in influenza circulation seasons. Based on these results, researchers said the flu vaccine did help to protect patients from influenza complications, including cardiovascular events.

“Many of the effects we found during peak flu circulation disappeared outside of it,” Dr Loeb said. “There’s no biological explanation for that other than influenza infections.”

While the study was conducted in countries where the flu vaccine is either not widely available or not common to receive, Dr Loeb said the results could likely be generalisable even in countries where flu vaccine uptake is higher. Study participants were allowed to get a flu vaccine outside of the study, but Dr Loeb said that there was no impact on the findings as very few did so. He added that the study was stopped early in four countries due to the COVID pandemic.

Loeb said that additional trials and large-scale observational studies could further clarify the health benefits of influenza vaccination in people with cardiovascular disease.

“I think this study offers an important message about vaccines generally – that it is important to do randomised controlled trials in populations that historically haven’t had a very high uptake of vaccines,” Dr Loeb said. “These types of [research] gaps have to be filled.”

Source: American College of Cardiology

Intranasal Flu Vaccine OK for Kids with Asthma

Young girl sneezing
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A small clinical trial published in Pediatrics has shown that intranasal flu vaccine is just as safe for children with asthma as the intramuscular vaccine. According to the researchers, within 42 days of vaccination, 10.8% of children who received the intranasal quadrivalent live attenuated influenza vaccine (LAIV4) had an asthma exacerbation compared with 14.7% of those who received the intramuscular quadrivalent inactivated influenza vaccine (IIV4).

According to the researchers, regardless of asthma severity, LAIV4 remained noninferior to IIV4. Among those with mild asthma, one of 25 kids who received the LAIV4 experienced an asthma exacerbation versus three of 16 in the IIV4 group, the researchers reported. In children with moderate to severe asthma, exacerbations occurred in seven of 49 in the LAIV4 group and seven of 52 in the IIV4 group.

“These data add to the compelling safety record of LAIV in children, including those with persistent asthma,” the researchers wrote.

The two groups also did not differ significantly in the frequency of asthma-related symptoms, including nighttime awakening, unscheduled albuterol use, cough, wheezing, or chest tightness, within 14 days of administration. Similarly, no differences were seen in peak expiratory flow rate, or changes in childhood asthma control test or asthma control test scores from baseline through 42 days.

At present, the CDC recommends against the nasal spray vaccine for children and people with asthma, citing an increased risk of exacerbations.

A previous study had suggested that the LAIV was linked increased asthma risk and reactive airway disease in children under 36 months of age, but more recent research has found no difference in risk between the LAIV and IIV, the researchers explained.

“Building off these previous studies, our prospective study suggests that LAIV may be appropriate for some children with asthma,” they noted.

“These data support reexamining precautions to using LAIV4 in children with asthma, which could be particularly important during influenza pandemics, at times when IIV4 supplies are limited, in situations of public/school mass vaccination clinics using LAIV, or for children with significant needle aversions,” they added.

The study was conducted over the 2018 and 2019 flu seasons with children aged five to 11 but expanded to include children ages 5 to 17 in its second year. The primary outcome of asthma exacerbation after 42 days was defined as an episode for which the participant sought medical care or a new prescription for corticosteroids.

The median age of the 151 enrolled participants was 9 years, and 58% were boys.

Systemic reactogenicity events in the 14 days after vaccination were not different between the LAIV4 and IIV4 groups, with the exceptions of myalgia and sore throat, which were more common in the IIV4 group.

Source: MedPage Today

Good Uptake of Flu Jabs for Children in Procedures

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Offering an influenza vaccination to children about to have surgery and general anaesthesia  at a US children’s hospital resulted in a great increase in flu vaccinations there. In their findings presented at the ANESTHESIOLOGY® 2021 annual meeting, the researchers also posited that this raised vaccination awareness.

“The ongoing threat of a simultaneous COVID pandemic and seasonal flu epidemic makes the widespread use of flu vaccines more important than ever,” said Tyler Morrissey, MD, lead author of the study and assistant professor of pediatric anesthesiology, Department of Anesthesiology, University of Colorado School of Medicine, Aurora. “Our research shows that having a standardised process for getting children vaccinated for flu while under anaesthesia during surgery provides a ‘teachable moment’ and opportunity to educate families on the importance of flu vaccination, and may be a model for other childhood vaccinations while under anaesthesia, including the COVID vaccine.”

Epidemics of seasonal flu occur annually. Although the CDC recommends that everyone 6 months and older receive a yearly flu vaccine, during the 2019-20 flu season, the authors noted that vaccination rates were less than 50% for adults and 60% for children.

In the study, the authors hypothesised that the perioperative period when patients are undergoing anaesthesia for surgery would be a ‘teachable moment’ for flu vaccination, which they defined as an event motivating individuals to spontaneously adopt risk-reducing health behaviours.

In October 2020, a standardised ‘Best Practice Alert’ process was implemented to actively offer flu vaccinations to all paediatric patients having general anaesthesia at the hospital In the preanaesthetic area, a care team member received a computer alert then determined if the child was eligible, discussed vaccination benefits and obtained parental consent for the vaccine. The vaccine was then administered in the operating room (OR) after the induction of general anaesthesia. Prior to the 2020-21 season, flu vaccinations under anaesthesia were only offered upon patient or family request.

The researchers found the number of children receiving perioperative flu vaccinations increased by 3500% after implementation of the institution’s standardised protocol, compared to the previous year. During the 2019-20 flu season, only 30 perioperative vaccines were administered. Prior to the intervention during the 2020-21 flu season, only 30 vaccines were given over a six-week period (1 Sept.–16 Oct.).  However, after the intervention that same season, 1063 flu vaccines were administered over a 25-week period (16 Oct.–31 March), with no reported vaccine-related complications.
“We’re super encouraged to see so many parents agree to have their children vaccinated for flu while undergoing anaesthesia,” said Dr. Morrissey. “The CDC has recommended that flu vaccination be offered to children 6 months of age and older at every health care seeking opportunity. As physicians on the front lines of the COVID pandemic, this is another great opportunity for our specialty to make a significant impact on public health.” 

Source: American Society of Anesthesiologists