PARIS (FRANCE) – In an unprecedented move by the governments that are struggling to tame fresh rises in COVID-19 infections, several European countries are considering mixing up COVID-19 vaccines for citizens who received the first dose of AstraZeneca’s shot.
A senior official for the European Medicines Agency (EMA) said in an interview published on Tuesday there was a link between the vaccine and rare blood clots in the brain but the possible causes were still unknown.
AstraZeneca has said previously its studies have found no higher risk of clots because of the vaccine, millions of doses of which have been administered worldwide.
In many instances, this has left officials scratching their heads over what to do for people who received the first dose of AstraZeneca but are no longer eligible under the new rules.
Any divergence to the EMA’s marketing authorisation would also be considered as “off label use”, meaning it would not be approved by the regulator and leave individual countries responsible for any possible side-effects.
Some experts say that, because all of the vaccines target the same outer “spike” protein of the virus, they could work together to train the body to fight off the virus. There is no evidence it will be as effective.
In France, where the vaccine can now only be used for those aged 55 or older, the issue affects hundreds of thousands of people.
A top health advisory body in charge of defining the use of vaccines, the Haute Autorité de la Santé (HAS), is also contemplating deploying a messengerRNA (mRNA) vaccine produced by Pfizer-BioNTech or Moderna as a second dose, according to two sources aware of the organisation’s plans.