The arrival of COVID-19 vaccines is good news. However, until now, many people are still concerned about the effectiveness and reliability of these vaccines. But you should know that before being approved , a vaccine must prove its harmlessness and effectiveness by successions of clinical trials, the results of which have been scrutinized by a panel of researchers.
A vaccine is therefore not authorized for use until it is approved by an independent agency of a country or group of countries, notably the FDA in the United States, the MHRA in the United Kingdom. and the European Medicines Agency (EMA) in the European Union.
Of many COVID-19 vaccines, only “ BNT162b2 ” from Pfizer and BioNTech and “ mRNA-1273 ” from Moderna have been approved in the United States and Canada. For information, BNT162b2 has been licensed in 9 countries around the world, including the UK, and by the EMA.
How do vaccines get their authorization for use?
During the approval process, vaccine safety data from initial laboratory experiments through to the manufacturing process is reviewed. An important part of this data consists of clinical trials which include three stages.
The first step is to check its safety and find the right effective dose on a small group of volunteers. The second step is to observe on more than a hundred volunteers who will receive the vaccine for some, and the placebo for others, if it really works. Then follows a third step which will focus on verifying on thousands of volunteers, to whom the vaccine or the placebo are randomly attributed, the existence of side effects.
If a trial is put on hold, for example in the case of the Johnson & Johnson vaccine a few weeks ago, or when one of the trial steps fails, the vaccine is not approved.
On the other hand, an approved vaccine passes to phase IV during which its administration is monitored, always in order to detect and collect undesirable effects and possibly very rare effects. This is the last step before the authorities in charge of medicines review the data to fail the vaccine candidate or to give their approval, followed by the issuance of a marketing authorization .
And once the new vaccines start to be widely distributed around the world, their use still remains under scrutiny. At the slightest problem, they go through a quick review and if necessary, will be subject to change.