COVID-19 vaccine for variants: Pfizer, Moderna test a third ‘booster’ dose for efficacy

As newer strains of the COVID-19 virus emerge, vaccine makers are preparing for the possibility that their shots will not work against the variants.

As the global community gets involved in the mass vaccination drive against the COVID-19 virus, many places are reporting the emergence of new strains of the pathogen. This has been a cause of worry for scientists as they cannot say just how effective the current vaccines will be against the newer variants of COVID-19. But many vaccine manufacturers are trying not to leave things to chance. Many experts were of the view that the present vaccines being administered to the masses are unlikely to offer 100 per cent protection against the virus. So, against this backdrop, it is indeed heartening to note that, in an attempt to ensure the effectiveness of their COVID-19 vaccines against new variants of the novel coronavirus, both Pfizer and Moderna are testing a third booster shot of their respective two-dose vaccines. This booster dose will ramp up the protection offered by the vaccines against the new variants. According to researchers, this booster study is very important to understand the safety of a third dose and the immunity afforded against circulating strains

Pfizer explores possibility of vaccine against South African variant

On February 25, Pfizer announced that it is studying a third booster dose in some people who received their first dose of the vaccine more than six months ago. The company specifically stated that emerging and future variants of the virus that causes COVID-19 were the reason for the study. The company also admitted that it is exploring the possibility of a new, "variant-specific vaccine" that would target B.1.351, the highly infectious South African variant.

Moderna too making variant specific vaccine

Moderna also announced that it has finished making a variant-specific vaccine to target B.1.351, the South African variant, and the company is ready to begin a Phase 1 clinical trial of the same. The company says that it will explore the use of the new vaccine as a"booster dose" for people who are already vaccinated. Moderna says that this booster shot will be analyzed in a Phase 1 clinical trial to see if it can boost immunity against the variants of concern.

But do we really need a booster dose?

As more variants of the COVID-19 virus emerges, researchers and vaccine manufacturers are actively preparing for the possibility that people will need to get another vaccination to keep the mutated and more infectious versions of COVID-19 at bay. The current approved vaccines are effective at preventing infection, but no one knows for how long immunity lasts. With evidence mounting that these vaccines may not be that effective against emerging variants, it is essential to do something about it. The vaccine makers are preparing for the possibility that their shots will not work against the variants. Hence, Pfizer and Moderna are moving quickly to adapt their vaccines for variants.

What the FDA says

The U.S. Food and Drug Administration has gone on record to say that the adapted vaccines will be tested, but the process won't be delayed. The agency has said that vaccine makers will be permitted to do small-scale studies of maybe a few hundred people to test the upgrades, instead of repeating large studies with tens of thousands of people for each vaccine.