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AstraZeneca Withdraws Covid-19 Vaccine Worldwide, Citing Surplus Of Newer Vaccines
AstraZeneca has begun the worldwide withdrawal of its Covid-19 vaccine due to a "surplus of available updated vaccines" that target new variants of the virus.
The announcement follows the pharmaceutical company in March voluntarily withdrawing its European Union marketing authorisation, which is the approval to market a medicine in member states.
On 7 May, the European Medicines Agency issued a notice that the vaccine is no longer authorised for use.
In a statement, AstraZeneca said the decision was made because there is now a variety of newer vaccines available that have been adapted to target Covid-19 variants. This had led to a decline in demand for the AstraZeneca vaccine, which is no longer being manufactured or supplied.
"According to independent estimates, over 6.5 million lives were saved in the first year of use alone and over 3bn doses were supplied globally," the statement said.
"Our efforts have been recognised by governments around the world and are widely regarded as being a critical component of ending the global pandemic. We will now work with regulators and our partners to align on a clear path forward to conclude this chapter and significant contribution to the Covid-19 pandemic."
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Other countries have already stopped supplying the vaccine. It has not been available for use in Australia since March 2023, though its use was already being phased out from June 2021 due to the widespread availability of newer vaccines.
AstraZeneca changed the name of its Covid vaccine to Vaxzevria in 2021. The vaccine was authorised for use in those aged 18 and older, delivered as two injections, usually into the muscle of the upper arm, about three month apart. It was also used by some countries as a booster shot.
Vaxzevria is made up of another virus of the adenovirus family modified to contain the gene for making a protein from SARS-CoV-2, the virus that causes Covid-19. The vaccine does not contain the virus itself and cannot cause the virus.
Although the vaccine was found to be safe and effective overall, it carried the risk of a rare but serious side-effect, known as thrombosis with thrombocytopenia, or TTS. The rare syndrome occurred in about two to three people per 100,000 who were vaccinated with the Vaxzevria vaccine.
The chair of epidemiology at Deakin University in Australia, Prof Catherine Bennett, said the vaccine had played a pivotal part in the worldwide fight against the virus, particularly in the early days of the pandemic when limited vaccines were available.
"It has saved millions of lives and that should not be forgotten," she said.
"It was a really important part of the initial global response. However, it targeted the initial ancestral variants. We've now moved into a vaccine chain where we have products available that are chasing the variants that are emerging.
"There's also a shift in the risk calculus as well, given populations are much more protected and, even though of course Covid still causes deaths, we are overall less vulnerable to the disease."
The latest Covid-19 vaccine advice issued by the World Health Organisation in April advised that formulations of Covid-19 vaccines should target the JN.1 lineage of the virus, which is displacing existing XBB lineage variants.
Study Unveils Crucial Insights Into How COVID-19 Vaccines Mitigate Severe Illness
A landmark study by scientists at the University of Oxford, has unveiled crucial insights into the way that COVID-19 vaccines mitigate severe illness in those who have been vaccinated.
Despite the global success of COVID-19 vaccination campaigns, concerns remain around the continued spread of this disease including in vaccinated individuals. For this reason, researchers at the Oxford Vaccine Group conducted an extensive investigation into the human immune response to COVID-19, in both vaccinated and unvaccinated individuals.
Employing contemporary "big-data" analyses, scientists can find novel associations between fundamental biological entities and indicators of the severity of a disease — to build patterns of health and disease. Results of this study categorically show a reduction in indicators of disease severity in those who had received the vaccine, demonstrating that the harmful inflammatory reaction to COVID-19 is less severe in those who have been vaccinated, when compared with those who haven't.
Professor Daniel O'Connor, Head of Bioinformatics at the Oxford Vaccine Group (OVG), led the study. He said: "These results confirm the efficacy of vaccination and its pivotal role in reducing the harmful consequences associated with COVID-19. The results of our research highlight the ChAdOx1 nCoV-19 vaccine's ability to modulate harmful responses to the SARS-CoV-2 virus, and therefore to reduce the severity of illness. The implications of these findings are far-reaching, offering evidence that is fundamental to future vaccine development and pandemic mitigation strategies. It also provides valuable guidance for policymakers and public health experts."
Better understanding of how vaccines can reduce the severity of infections caused by viruses like COVID-19 is a key part of our preparedness to make effective vaccines against the next pandemic threat. Ongoing research is critical as we know the next one is coming but we don't know which virus or when it will be."
Professor Sir Andrew Pollard, Ashall Professor of Infection and Immunity and Director of the Oxford Vaccine Group
The study employed state-of-the-art technologies, including RNA-sequencing (to capture the level of genes produced by blood cells), to achieve these results. While the findings are promising, the study acknowledges limitations such as a focus on mild cases and sample size constraints, highlighting the need for further research utilising advanced techniques to enhance resolution.
Key findings from the study include:
Funding for the study was provided by various organisations, including the National Institute for Health Research (NIHR), Oxford Biomedical Research Centre, and Oxford Nanopore Technologies. Notably, the ChAdOx1 nCoV-19 randomised controlled trials received support from UK Research and Innovation, NIHR, Coalition for Epidemic Preparedness Innovations, Bill & Melinda Gates Foundation, among others.
Source:
Journal reference:
Drury, R. E., et al. (2024). Multi-omics analysis reveals COVID-19 vaccine induced attenuation of inflammatory responses during breakthrough disease. Nature Communications. Doi.Org/10.1038/s41467-024-47463-6.
MMR Vaccines May Not Always Give Lifelong Immunity Against Measles
Falling uptake of the MMR vaccines has led to a resurgence of measles in countries such as the UK
angellodeco/Shutterstock
Receiving two vaccine doses against measles as a child may not always lead to lifelong immunity, despite what is commonly thought, according to a modelling study. Even so, this remains the best way to safeguard against the illness.
The level of protection seems to fall by a very small amount per year, which could explain why a growing number of people are catching measles despite having had two vaccines against it…
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