3rd time’s the charm? Pfizer/BioNTech to study if THREE doses of Covid-19 vaccine can boost immunity against variants

Pfizer and BioNTech will launch a new trial of the Covid-19 vaccine they jointly developed to see if a third dose can act as an effective booster against emerging variants of the virus, they said in a statement on Thursday.

The study will use participants from a current US trial, who will be given a booster shot of the current vaccine between six to 12 months after receiving their initial two-dose regimen.

According to the statement, 144 Phase 1 participants across two age groups will receive a third dose – people aged 18-55 and 65-85.

The companies also said that, as originally planned, all of the trial participants will be monitored for up to two years.

“We believe that the third dose will raise the antibody response 10- to 20-fold,” Pfizer CEO Albert Bourla said during an NBC interview.

In his earlier statement, Bourla said Pfizer has not seen any evidence to suggest that its 95-percent-effective vaccine is less effective against new variants.

However, he added that the study is critical to understanding the safety of a third dose and immunity against new variants.

On Thursday, Pfizer also announced that it will conduct clinical trials for a modified version of its mRNA vaccine against the B.1.351 Covid-19 variant first identified in South Africa.

Pfizer confirmed it is in talks with US and EU regulators, the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) respectively, about the plans.

The FDA told manufacturers on Monday to prepare for new variants of the virus, including by testing modified vaccines on those who have already been injected and those who haven’t.

The FDA also said that discussions were ongoing into whether, in the future, tweaked vaccines “may be authorized without the need for clinical studies.”

Like this story? Share it with a friend!