Researchers in the UK have found that the protection offered by the Pfizer/Biotech and AstraZeneca vaccines begins to fall after six months. The researchers have linked this to the need for booster shots for those who already had two doses of the vaccine.
While major countries like the US, UK and also the EU are planning to administer booster shots, there has been some criticism and scepticism. Some researchers believed there was no evidence that booster shots were necessary. Some also believe it would be morally wrong to start giving people a third dose many people are unable to access the vaccines at all.
The EMA safety committee held a meeting on 18th March and found that:
the benefits of the vaccine in combating the still widespread threat of COVID-19 (which itself results in clotting problems and may be fatal) continue to outweigh the risk of side effects;
the vaccine is not associated with an increase in the overall risk of blood clots in those who receive it;
there is no evidence of a problem related to specific batches of the vaccine or to particular manufacturing sites;
however, the vaccine may be associated with very rare cases of blood clots associated with thrombocytopenia, i.e. low levels of blood platelets (elements in the blood that help it to clot) with or without bleeding, including rare cases of clots in the vessels draining blood from the brain (CVST).
Several countries across Europe have suspended the AstraZeneca vaccine due to safety concerns. There have been reports of blood clotting and deaths in people who have been administered the vaccine.
In comparison, there seems to be little trouble with the rollout of the vaccine in the UK with scientists there insisting that the jab is safe.
What happens next?
The European Medicines Agency is currently reviewing the issue, along with the Moderna and Pfizer-Biotech vaccines which have also been linked to blood clotting. The EMA executive director, Emer Cooke, said:
There is no indication vaccination has caused these [blood clotting] conditions.
However, like with any form of medicine, we will only find the answers through continuous testing.
Currently, WHO has stated that it is safe to continue using the AstraZeneca vaccine and indications are that the suspensions may not last, particularly in Europe where some countries are experiencing a third wave of infections.
16th March 2021:
WHO is investigating the reports and working closely with the European Medicines Agency.
As soon as review of the data is finalized, we’ll inform the public of any findings.
For the moment, the European Medicines Agency’s position is that the benefits of the AstraZeneca vaccine in preventing COVID-19, with its associated risk of hospitalization and death, outweigh the risks of side effects.
WHO’s Global Advisory Committee on Vaccine Safety (GACVS) is meeting today to review the reports of rare blood coagulation disorders in persons who had received the AstraZeneca vaccine.
As per History of Vaccines, “Pierre Paul Émile Roux (1853-1933) was a protégé of Louis Pasteur and a pioneer in bacteriology and immunology.” He was a French bacteriologist known for his research into tetanus and diphtheria. He also worked on the development of vaccines with Pasteur.