Amid uncertainty over the use of AstraZeneca vaccine in many regions including Europe, the top health body in France said people who got the first dose of AstraZeneca vaccine should receive a messenger-RNA vaccine as the second dose.
The Haute Autorite de la Sante (HAS), which is tasked with deciding how vaccines can be rolled out in France, was considering this option, Reuters reported.
Earlier this week, the European Medicines Agency (EMA) said found a possible link between AstraZeneca vaccine and the rare cases of blood clots in people who had received the shot.
Citing sources the agency reported that HAS is going ahead with the use of two mRNA vaccines --- Pfizer-BioNTech and from Moderna -- for those aged below 55.
Meanwhile, Germany had also instructed that people below the age of 60 who got the AstraZeneca shot must opt for a different vaccine as the booster dose.
This is an interesting development as the procedure to give a different vaccine as the second dose was not tested during any human trials so far.
Reuters cited an expert saying that all these vaccines are complementary as all of them target the same "spike" protein of the coronavirus.
How Messenger RNA Vaccines Work
Messenger RNA vaccines prompts the body to make a protein that mimics part of the virus and trigger immune response. Clinical studies demonstrated that mRNA-based vaccines induce potent and broadly protective immune responses against the coronavirus. Viral vector vaccines such like those made by AstraZeneca employ a common cold virus to release DNA instructions to achieve the same objective.
Meanwhile, safety concerns forced several countries in recent weeks to suspend use of the vaccine. Reports said on Friday that more countries suspended the use of AstraZeneca vaccine due to concerns over blood clots. Australia and the Philippines said they were limiting the use of AstraZeneca's COVID-19 vaccine. The African Union also said it was not going ahead with the plans to buy more vaccine shots.
The EMA statement revealing a possible link between AstraZeneca vaccine and blood clots dealt a significant blow to AstraZeneca, which makes the cheapest vaccine by far.
At the same time, both the EMA and the World Health Organization insist that the benefits outweigh the risks of the vaccine. "The risk of mortality from COVID is much greater than the risk of mortality from these rare side effects," EMA's executive director Emer Cooke said on Wednesday.
AstraZeneca said it is working with regulators to classify the brain blood clots as an 'extremely rare' potential side-effect of the vaccine.