Filenews 9 July 2021
Us company Pfizer and German BioNTech have announced that they are developing a new vaccine - essentially an upgrade of their existing vaccine - specifically aimed at the more contagious Delta variant of the coronavirus and plan to begin its clinical trials in August.
The two companies - which will be the first to create a vaccine specifically against Delta - consider this to be an extra weapon if a booster dose of their existing vaccine proves insufficient against Delta.
At the same time, they reported encouraging results from studies of people who received a third supporting dose of their existing vaccine. The extra dose, six months after the second, increased the strength of antibodies against the original strain of the virus and against the Beta variant ('South African') by five to ten times.
The effectiveness of the current vaccine may be reduced six months after administration and therefore, according to the two cooperating companies, a booster dose may be needed in particular against coronavirus variants. The relevant data, which has not yet been released, is due to be submitted to the US Food and Drug Administration (FDA) in the coming weeks, taking the first step towards getting approval to administer a booster dose, according to the New York Times, Reuters agency and the Financial Times.
However, other experts do not consider an extra dose necessary, at least for the time being. "There really is no indication in favour of a third booster dose of an mRNA vaccine, given the variants currently circulating. In fact, many of us are wondering if they will ever need booster doses," said infectious disease specialist Dr. Celine Gauder of Bellevue Hospital in New York City.
In a joint statement, the FDA and the US CDC said that fully vaccinated people do not so far need an extra dose. "We are prepared for booster doses, if and when science shows that they are needed," the two organizations stressed.
Citing data from Israel, Pfizer and BioNTech argue that the effectiveness of the existing vaccine "shows a decrease of six months after vaccination, both in terms of preventing infection and symptomatic disease." Taking into account the spread of Delta, the two companies estimate that "a third dose may be needed within six to 12 months after full vaccination".
Pfizer chief scientist Michael Dolsten said that, according to data from Israel and Britain, the current vaccine remains about 95% effective against serious disease from any variant. He also said some European countries have begun discussions with the company to administer booster doses, and some may do so before the FDA even gives its approval for doing so. He also pointed out that the extra third dose is particularly important for the elderly.
The Israeli health authorities estimated - based on newer data in June - that the two doses of the Pfizer/BioNTech vaccine provide protection only 64% against Delta in terms of infection and simple symptomatic disease, but 93% in terms of serious disease and hospitalisation due to Delta. But this assessment conflicts with other studies that have concluded that the vaccine is very effective against all variants.
"Pfizer displays an opportunism, basing its announcement on very early and 'ingr' elements from Israel. When the right time comes for booster doses is a decision the company won't make," saidologist John Moore of New York's Weill Cornell School of Medicine.
The new vaccine under development against Delta will target all the protein-spike of the coronavirus and not just part of it as it has so far. The first batch of the test vaccine has already been produced. Pfizer expects sales of $26 billion from its anti-coronavirus vaccine this year, as well as big revenue in the coming years.
Source: RES-BE
