Pfizer Studying 3rd Dose of Its COVID-19 Vaccine To Target New Variants

Despite its 95-percent efficacy at preventing COVID-19 infection after two doses of vaccine, Pfizer is currently studying what another dose, a third one, might do.

The vaccine maker announced that a booster dose is currently being studied among those who already got their first doses of the vaccine over six months ago.

In an interview with NBC News, Albert Bourla, CEO of Pfizer, said that they hope that another dose will enhance the immune response even higher, providing a better shield from coronavirus variants. The company CEO said that they believe that the third dose will raise the antibody response from ten to twenty-fold.

This said study is set to monitor the third dose's safety and efficacy in two age groups: one with participants aged 18 to 55; and the other, those who are 65 to 85 years old.

All participants came from a group of individuals who were among the first recipients of the Pfizer-BioNTech vaccine. They were the ones who volunteered for the initial Phase 1/2 clinical trial of Pfizer, which started in May 2020.

Third Dose

During the trial, participants were given two doses of the vaccine with a three-week interval. The same dose interval, the company said, is what's presently being recommended.

The company executive also said that the third dose would exactly be the same as what the volunteers were given last year.

Pfizer is also planning to start testing if a modified version of the vaccine is effective against the variant that originated in South Africa.

Certainly, as COVID-19 changes, the vaccines may need to be tweaked. Earlier on, the Food and Drug Administration (FDA) released guidance stating that vaccine makers may be able to ease away from long clinical tests to prove safety and efficacy for vaccines that have been tweaked to account for strains.

So far, evidence proposes that the present vaccine of Pfizer and BioNTech stays effective as shield from the variants originally detected in the United Kingdom, Brazil and South Africa.

Efficacy of the Current Doses

In a similar report, the Insider said specifically, the current doses from Pfizer could shield against B.1.351 and B.1.1.7, a more communicable strain that initially took place in the UK.

However, Pfizer is getting ready for this possibility that it might ultimately need to develop additional vaccines that would target the variants.

The CEO said, while they have not seen any evidence yet that the spreading variants result in loss of protection which their vaccine provides, they are taking several steps to act determinedly and prepare in case a variant turns out to be resistant to the shield afforded by the vaccine.

Bourla also said, the goal of Pfizer if and when another strain occurs, is to pivot and tweak the present vaccine within 100 days.

Moderna, which is also manufacturing similar COVID-19 vaccine, announced that it began studying the impacts of a third dose on its regimen and has developed a version of the shot designed to target the strain from South Africa.

That's not unlike how the changes are with flu shot from year to year, accounting for variants, most possible to infect people.

A similar report is shown on below on WPRI 12's YouTube video:

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