Tag: smallpox

Categories : Diseases, Syndromes and Conditions VaccinesTags :

More Monkeypox Antibodies with Childhood Smallpox Vaccination

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Mpox (monkeypox) virus. Source: NIH

In a study published in Cell Host & Microbe, scientists studied the sensitivity of MPXV, the virus that causes mpox (formerly monkeypox) to neutralising antibodies (NAbs) generated after infection with the virus and/or vaccination with IMVANEX. They found that those who had been born before 1980 had more antibodies in response to either IMVANEX vaccination or mpox infection, highlighting the lasting protection of smallpox vaccination.

The IMVANEX vaccine has been used as pre- and post-exposure prophylaxis in high-risk populations, but its effectiveness is not yet well characterised. To analyse the sensitivity of the virus, a team of scientists led by Pasteur Institut developed two cellular tests to quantify neutralising antibodies, using either the attenuated virus as a vaccine (MVA) or an MPXV strain isolated in a recently infected individual.

In 2022-2023, an unprecedented epidemic of 87 000 cases of mpox occurred in non-endemic areas, affecting people with no direct link to travel in Central or West Africa, where the virus has historically been present. MPXV is mainly transmitted to humans by rodents, with human-to-human transmission occurring via respiratory droplets or close contact. Symptoms are less severe than those of smallpox, and the case-fatality rate is lower. MPXV is still circulating at very low levels in non-endemic areas, which is why it is important to improve characterisation and analyse the immune response of people infected with the virus or vaccinated with IMVANEX, the third-generation vaccine currently available, initially developed for smallpox.

The large number of sera analysed provided good statistical power, meaning that the analysis could be narrowed to subgroups of patients based on various criteria such as age.

The study demonstrated the role of complement, already known for other poxviruses, and the neutralising activity of the antibodies generated by infection or vaccination. Robust levels of anti-MVA antibodies were detected after infection, vaccination with the historic smallpox vaccine, or administration of IMVANEX or another MVA-based vaccine candidate. MPXV was minimally sensitive to neutralisation in the absence of complement. The addition of complement from sera enhanced detection of individuals with antibodies and increased their level of anti-MPXV antibodies. Four weeks after infection, anti-MVA and -MPXV NAbs were observed in 94% and 82% of individuals, respectively. Two doses of IMVANEX generated anti-MVA and -MPXV NAbs that were detectable in 92% and 56% of vaccinees, respectively.

The highest level of antibodies was found in individuals born before 1980 (who had therefore been vaccinated for smallpox), whether after infection or after administration of IMVANEX, highlighting the impact of historic smallpox vaccination on immune responses to infection or administration of IMVANEX. This suggests that a sort of hybrid immunity was generated in infected individuals who were vaccinated in childhood.

The number of MPXV infections has been constantly on the rise since mass vaccination for smallpox was discontinued in the 1980s. “The neutralisation assays developed in connection with this research may help define correlates of protection against infection or disease severity. The assays can also be used to conduct epidemiological surveys, assess the duration of protection conferred by previous infection or by authorised and candidate vaccines, and analyse the use of immunotherapeutic intervention. The assays represent useful tools to understand the mechanisms of multiplication of MPXV and its effects on public health, and to optimsze patient treatment,” commented Olivier Schwartz, Head of the Institut Pasteur’s Virus and Immunity Unit and last author of the study.

Source: Institut Pasteur

Categories : Diseases, Syndromes and Conditions PaediatricsTags :

18th & 19th Century Grannies Protected Their Grandchildren from Infectious Diseases

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Photo by CDC on Unsplash

While grandmothers today have a popular image of spoiling their grandchildren with treats, in premodern times they also acted as healthcare providers. To find out more, University of Turku researchers looked at historical data on childhood mortality from infectious diseases in the 18th and 19th century in Finland. The study, which is published in the journal Proceedings of the Royal Society B, found that grandmothers decreased all-cause and cause-specific mortality of children.

In historical and in several contemporary societies, children with living grandmothers are more likely to survive into adulthood, but the mechanism behind this effect remains poorly known.

As childhood infections have been a leading cause of death in children under the age of 5 years, the researchers aimed to investigate whether the effect of grandmothers on childhood survival was related to providing knowledge in childcare, particularly during critical times such as epidemics. One way for grandmothers to do so could be by encouraging vaccine uptake or earlier vaccination against childhood infections, as has been observed in some contemporary populations.

Researchers first studied the effects of grandmothers on children’s cause-specific mortality, using historical records of five causes of death: smallpox, measles, pulmonary infections, diarrhoeal deaths, and accidents. The large multigenerational dataset of pre-industrial Finnish families included 9705 individuals from 12 parishes across Finland, where the survival of individuals until the of age 15 years was monitored from 1761 to 1900. In the second part of the study, the researchers determined whether increased survival against the childhood infection smallpox was mediated by vaccination. To this end, they used 1594 vaccination records from two rural parishes and matched them to their individual family histories.

The results show that grandmothers decreased all-cause mortality, an effect which was mediated through improved survival from smallpox, pulmonary and diarrhoeal infections, but not from measles or accidents. However, the researchers found no evidence of increased or earlier vaccination between children with or without grandmothers.

“Our results show that the grandmother’s presence protected against some childhood infections, which could indicate that in historical Finnish society, the assistance provided by grandmothers in childcare was likely an important factor in ensuring the survival of children,” says study lead author, Doctoral Researcher Susanna Ukonaho.

Grandmothers in contemporary societies

Although grandmother care provided health benefits in many historical societies, these benefits may no longer be relevant in contemporary societies. The progress in healthcare during the 20th century especially in high-income countries likely decreased the role of grandmothers. However, some studies indicate that grandmothers improve childhood survival in several contemporary middle- and low-income countries.

“The type of benefits that grandmothers provide may vary depending on cultural contexts and individual circumstances. Even though in many societies grandmothers are no longer essential for childhood survival, their efforts in childcare remain valuable for the well-being of the whole family,” says Ukonaho.

Source: University of Turku

Categories : VaccinesTags :

Smallpox Vaccine Offers Protection Against Mpox

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Photo by Gustavo Fring on Pexels

Smallpox vaccines offer continuing cross-reactive immunity to mpox (previously known as monkeypox), researchers from Karolinska Institutet in Sweden report in a study published in the scientific journal Cell Host & Microbe. The smallpox vaccine had been administered in Sweden from the early 19th century until it was discontinued in 1976 with the eradication of the disease.

During last year’s mpox outbreak, the virus spread for the first time outside Africa, causing over 85 000 cases of the disease to date. Men who have sex with men account for the most infections, with a marked skew towards the young.

The virus that causes mpox is what is known as an orthopoxvirus and is very similar to the virus that caused smallpox until the mid-1970s when it was finally eradicated. South Africa stopped its smallpox vaccinations in 1982.

Since there were data indicating that the old smallpox vaccine could protect against mpox, the researchers at Karolinska Institutet wondered if the individuals who were vaccinated decades ago against the former would have some protection against the latter owing to a remaining memory response.

“Our study shows that this is the case, which implies that the memory cells are very long-lived and that they can recognise closely related viruses such as the mpox virus and provide overlapping, or cross-reactive immunity,” says the study’s corresponding author Marcus Buggert, docent and researcher at the Center for Infectious Medicine, Karolinska Institutet.

By analysing the T-cell immune response in 105 healthy blood donors, the researchers were able to show that individuals born before 1976 had a significantly stronger immune response against both viral types. The researchers also analysed the immune response in 22 men with a recent mpox infection and showed that they also exhibited a strong immune response to the virus, which may provide future immunity.

The current study was too small to judge how much protection previous smallpox vaccination provides, but Dr Buggert refers to a recently published British observational study examining the effect of a smallpox vaccine given to risk-group males in 2022.

“This study shows that smallpox vaccine can provide about 80% protection against mpox,” he says.

Source: Karolinska Institutet

Categories : Diseases, Syndromes and ConditionsTags :

80 Cases of Monkeypox Reported in 12 Countries

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Close-up of monkeypox lesions on the arm and leg of a female child. Credit: Wikimedia Commons

On Friday, May 20, the World Health Organization has reported that there were 80 cases of monkeypox reported in 12 countries, but has not mentioned which countries those are. However, the National Institute for Communicable Diseases has not reported any cases in South Africa, though there has now been a case reported in Australia.

Update: as of 23 May, the NICD has reported that there are 145 cases in 15 countries, but confirms there are no local cases.

Normally endemic to certain countries where it resides in animal reservoirs, monkeypox is rarely encountered in countries outside those regions. The WHO notes that this is “atypical” for the zoonotic orthopoxvirus, which causes smallpox-like symptoms but with a lower mortality. European public health agencies have so far reported that the UK, Spain, Portugal, Germany, Belgium, France, the Netherlands, Italy and Sweden have seen cases. The first patient in the UK with the virus had returned from a trip to Nigeria, likely catching it there. Cases have been reported in the US and Canada.

The WHO advises that, “As monkeypox spreads through close contact, the response should focus on the people affected and their close contacts. People who closely interact with someone who is infectious are at greater risk for infection: this includes health workers, household members and sexual partners.”

At present, it is unclear why this unusual outbreak is happening now, especially amid the heightened vigilance of the COVID pandemic. One possibility is that some mutation is responsible, though there is little evidence at present to suggest a new variant is responsible.

Another explanation could be that this is simply a matter of the right place and time for the virus. It may also be easier for monkeypox to spread nowadays compared to when there was more widespread use of smallpox vaccine.

Source: BBC News

Categories : COVID UncategorizedTags :

COVID Eradication is Tough but not Impossible, Study Shows

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Image by Ivan Diaz on Unsplash
Image by Ivan Diaz on Unsplash

A new analysis shows that the global eradication of COVID is tough but theoretically more feasible than for polio and less so than it was for smallpox.

The article in BMJ Global Health ranked the feasibility of eradicating the three diseases based on technical, socio-political and economic factors.

Smallpox, which was declared eradicated in 1980, had the highest average score for eradication feasibility. It had an average score of 2.7 on a three-point scale across 17 variables.  COVID had an average score of 1.6 which was close to polio’s average score of 1.5.

Professor Nick Wilson from the University of Otago said that their analysis shows COVID’s eradication is feasible.

Vaccination programmes, public health measures and the global interest in combating the disease together contribute to making eradication possible.

“Elimination of COVID-19 at the country level has been achieved and sustained for long periods in various parts of the Asia Pacific region, which suggests that global eradication is possible.”

Vaccination programmes eradicated smallpox and two of the three serotypes of poliovirus, while other diseases are close to eradication. China recently became the 40th country to be certified malaria-free.

In ranking the feasibility of eradication for the three diseases, the researchers incorporated factors including the availability of safe and effective vaccines, the possibility of lifelong immunity, the impact of public health measures, effective infection control messaging by governments, political and public concern about the infection and public acceptance of infection control measures.

While there has been a focus on the need to reach herd immunity to overcome COVID, population immunity may not be essential to combat the disease, as smallpox was eradicated through ring-vaccination programmes which target the contacts of those infected.

The challenges of eradicating COVID relative to smallpox and polio include poor vaccine acceptance in some countries and the emergence of variants of the pandemic virus that may be more transmissible or able to evade the protection from vaccines.

But Professor Wilson said eventually the virus will be reach the limit of more infectious mutations, and so new vaccines will likely be formulated to deal with evolving strains of the disease.

Other obstacles includedthe cost of global vaccination and upgrading health systems, and achieving international cooperation in the face of aggressive anti-science movements and vaccine nationalism.

Professor Wilson says while the virus may infect animal populations, they will note likely hamper eradication.

“Wild animal infections with SARS-CoV-2 appear to be fairly rare to date and when companion animals become infected, they don’t appear to reinfect humans.”

A co-author of the article, Professor Michael Baker from the University’s Department of Public Health, says global concern about the pandemic could be tapped.

“The massive scale of the health, social and economic impacts of COVID-19 in most of the world has generated unprecedented global interest in disease control and massive investment in vaccination programmes.

“Unlike smallpox and polio, control of COVID-19 also benefits from the added impact of public health measures, such as border controls, social distancing, contact tracing and mask wearing, which can be very effective if well deployed.”

Professor Baker says upgrading health systems to target COVID-19 could also help to control other diseases, and could even aid in eradicating measles.

“When all factors are taken into account, it could be that the benefits of eradicating COVID-19 outweigh the costs, even if eradication takes many years and has a significant risk of failure.”

This work is preliminary, the researchers cautioned.

“The World Health Organization or a coalition of national agencies working collaboratively needs to formally review the feasibility and desirability of attempting COVID-19 eradication on a global basis,” Professor Baker says.

The researchers noted it is important to distinguish between eradication of infection, ie the permanent reduction to zero of the worldwide incidence of infection caused by a specific agent as a result of deliberate efforts; and elimination, ie the reduction to zero of the incidence of infection caused by a specific agent in a defined geographical area as a result of deliberate efforts.

COVID elimination has been reached and sustained for long periods in a number of jurisdictions in the Asia-Pacific region (notably China, Hong Kong, Taiwan, Australia and New Zealand), demonstrating that global eradication is technically possible.

Source: EurekAlert!