Pfizer Inc and BioNTech testing the third dose of their Covid-19 vaccine

In a view to better understand the immune response against the new strain of the virus, Pfizer and BioNTech SE on Thursday has said that they are testing the third dose of their vaccine against the deadly virus.

There has been continual talks with the regulatory authorities regarding the test of a vaccine developed to offer protection against the highly transmissible new strain reported in South Africa and in other countries, famed as B.1.351.

There is a firm belief in the company that their current two-dose vaccine shall be fruitful in tackling the South African variant as well as the variant found in the United Kingdom and in other places. They added that the studies shall grant opportunities to the vaccine makers to be prepared if and when more protection is required.

In an interview, the Chief Scientific Officer of Pfizer, Mikael Dolsten has said, “The rate of mutations in the current virus is higher than expected”.

He also added, “It’s a reasonable probability that we would end up with regular boosts. And for potent vaccines, it may be that you need to do a strain change every few years, but not necessarily every year”.

During the first stage of the first arm of the study, a third 30 microgram dose shall be given to 144 people who had been vaccinated 6 to 12 months before in the original Phase 1 safety trial.

Dolsten stated that in assuming the regulatory approval, a redesigned vaccine would be tested as a booster dose in people who have received the vaccination as well as not.

Unlike the large Phase 3 trial last year, the trial would not measure the effectiveness of the vaccine. But, it would measure the antibody response and determine whether the blood from recipents can neutralize the effect of the new strain of the virus and also provide safety of a third dose.

According to U.S. government data, the first case of the South African variant was detected in the month of January, thus spreading to 14 other states. Several studies have proved it to be more resistant to the existing vaccines in comparison to the other variants of coronavirus.

Dolsten from Pfizer have stated that like Pfizer and BioNTech vaccines, mRNA vaccines also produce a potent response, but the immune response may fade over time.

He is of the opinion that the third dose of their vaccine shall produce the same or a far better response in comparison to the second dose and can be a logical step for staying ahead of the existing variants.

Observing that the companies “want to be prepared for all options and be data-driven”, Dolsten further commented, “We think our vaccine is robustly active against all strains”.

According to Dolsten, the new trial is expected to be predominantly carried on in the United States.

On Wednesday, Moderna Inc told that it is working in collaboration with the U.S. government scientists on a study of experimental booster shot that aims the variant first detected in South Africa.