After maintaining the need for a booster dose within six to 12 months of vaccination against COVID-19, Pfizer will soon approach regulators for authorization of its booster dose, the company said in a press release. The move is aimed to help countries stay ahead of the virus and its variants that have been emerging in various parts of the world.
In the released statement, the company also acknowledged the report from Israel's Health Ministry that saw a drop in protection offered by the vaccine in a real-world scenario. The company said that the report was consistent with the company's analysis of its Phase 3 trials that vaccine efficacy declines after a period of six months, making a case for the booster dose, even after full vaccination.
In a yet unpublished study, Pfizer saw that a booster given after six months of vaccination, elicited neutralization titres, against the wild-type and Beta variants, that were 5-10 times higher than the previous doses. The company pointed to a Nature paper that demonstrated under laboratory conditions, strong neutralization titres against the Delta variant, in sera obtained from fully vaccinated individuals. Currently, Pfizer is conducting clinical trials to confirm this in the field.
Apart from the booster dose strategy, the company is also working on an updated version of its vaccine that will contain the full-spike protein of the Delta variant, CEO Albert Burla tweeted.
We have seen initial encouraging data in the booster study for our current #COVID19 vaccine, but we are also remaining vigilant and developing an updated version of the vaccine that targets the full spike protein of the Delta variant: https://t.co/CI5ZiY4jEn (1/3)— AlbertBourla (@AlbertBourla) July 8, 2021
The first batch of mRNA for trials has already been manufactured and the company is awaiting regulatory approvals to begin the clinical trials in August.
While Pfizer's vaccine was effective against other variants, the Delta variant has become an issue of concern of late. The rising number of cases has forced countries to push back plans of returning to normal life.
As of now, the Pfizer vaccine has Emergency Use Authorization for active immunization to prevent COVID-19 in all individuals over 12 years of age in the US.