United Kingdom

Pfizer scientists are studying whether a THIRD vaccine shot can offer protection

Pfizer Inc announced on Thursday it has begun studying a third dose of its COVID-19 vaccine, part of a strategy to guard against mutated versions of the coronavirus.

Health authorities say first-generation COVID-19 vaccines still protect against variants that are emerging in different parts of the world including the UK and South Africa.

But manufacturers are now starting to prepare in case a more vaccine-resistant mutation comes along. 

Pfizer and its German partner, BioNTech SE, said it will offer a third dose to 144 volunteers, drawing from people who participated in the vaccine's early-stage U.S. testing last year. 

It wants to determine if an additional booster shot given six to 12 months after the first two doses would rev up the immune system enough to ward off a mutated virus.  

Pfizer Inc and its German partner BioNTech are studying a third dose of their coronavirus vaccine, which is aimed at protecting against future variants. Pictured: A health worker shows a vial of the Pfizer-BioNTech COVID-1) vaccine, in San Jose, Costa Rica, February 24

Variants spreading across the U.S. including the one from South Africa (purple dot), are better at evading antibodies from vaccine than earlier strains of the virus

Researchers believe if the shot is given six to 12 months after the first two doses, it may help stimulate the immune system enough to ward off a mutated virus as the U.S. vaccinates about 1.2 million people per day

'The rate of mutations in the current virus is higher than expected,' Pfizer Chief Scientific Officer Mikael Dolsten told Reuters in an interview.

'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.'

The vaccine candidate from Pfizer and BioNTech uses part of the pathogen's genetic code called messenger RNA, or mRNA, to get the body to recognize the coronavirus and attack it if a person becomes infected.

In the jab, known as BNT162b2, the mRNA encodes for all of the spike protein found on the outside of the virus that it uses to enter and infect cells. 

It was authorized for emergency use by the U.S. Food and Drug Administration (FDA) after a clinical trial involving 44,000 volunteers found the shot was 95 percent effective at preventing symptomatic COVID-19.

The two-dose Pfizer-BioNTech vaccine was the first authorized for use in the U.S., in December, after a large global study in 44,000 people found the shot was safe and 95% effective at protecting against symptomatic

However, the company's current two-dose regimen produced a weaker immune response against the South African variant. 

Recently, in a study punished in the New England Journal of Medicine, Pfizer teamed up with the University of Texas Medical Branch to test its vaccine against the variant known as B.1.351.

They found that only one-third of its neutralizing antibodies were activated compared with its effect on the most common version of the virus prevalent in U.S. trials.

However, the pharmaceutical giant said the actual efficacy of its vaccine against the South African variant is yet to be determined.  

'While we have not seen any evidence that the circulating variants result in a loss of protection provided by our vaccine, we are taking multiple steps to act decisively and be ready in case a strain becomes resistant to the protection afforded by the vaccine,' Pfizer CEO Albert Bourla said in a statement.

'At the same time, we are making the right investments and engaging in the appropriate conversations with regulators to help position us to potentially develop and seek authorization for an updated mRNA vaccine or booster if needed.' 

It currently unclear when Pfizer and BioNTech will have results on the efficacy of the booster shots but, during an earnings call earlier this month, Pfizer R&D chief Mikael Dolsten said preliminary data may be available in early summer.  

Pfizer and BioNTech are also are tweaking their vaccine recipe. 

The companies are in discussions with U.S. and European regulators about a study to evaluate doses updated to better match variants such as B.1.351.

Pfizer's approach is different from than of Moderna Inc, which announced yesterday it had made a new vaccine as a booster and had sent doses to the National Institutes of Health for testing.

Moderna's vaccine, like Pfizer's, is made with new mRNA technology and also needs to be stored at freezing temperatures.

Also like Pfizer, Moderna's shot was found to be less effective against the strain.

Recently, the FDA said any company developing a booster would have their results analyzed quickly and would not need large efficacy trials to be approved.

Football news:

We decide when you play. Manchester United fans have blocked the base-waiting for the sale of the club amid the collapse of the Super League
Josh Kroenke - Arsenal fans on Super League: We were wrong. Do you still want cold evenings in Stoke
Atalanta does not lose 6 matches: 5 wins and a draw. Miranchuk was not released in the last two
Ilkay Gundogan: The new format of the Champions League is just the lesser of two evils compared to the Super League. There will be more matches - and no one thinks about the players
Ceferin's salary increased by 450 thousand euros, despite a 21% drop in UEFA revenues due to the pandemic
Lineker on Barca's Super League statement: It is disappointing
Orlov on the transfer of matches from Dublin to St. Petersburg: The issue is resolved by 99%. I am a knowledgeable person