Early results were announced today for clinical trials involving 43,538 volunteers that showed a robust 90% success rate for protecting people against coronavirus.
As part of the Phase–3 trials launched in July by developers Pfizer and BioNTech, the participants from diverse backgrounds in six countries—in the US, Germany, Brazil, Argentina, South Africa, and Turkey—received two injections spaced 21 days apart.
The analysis compared the number of cases of COVID-19 among volunteers receiving the vaccine with an approximately equal-sized group of volunteers who got a placebo jab, instead. The researchers reported no contraction of the disease in over 90% of the vaccinated group, so far, with immune protection achieved 28 days after the first dose of the 2-dose schedule.
The US Food and Drug Administration (FDA) set a minimum effectiveness bar for COVID-19 vaccines at 50% for drugs seeking approval. This is the first COVID-19 candidate vaccine to produce data exceeding that mark.
The data presented is only an early look into how the new vaccine seems to be performing. Further safety and efficacy data continue to be collected.
Relying on an independent Data Monitoring Committee to analyze the results, Pfizer and BioNTech say they are continuing to accumulate safety data and estimate that a median of two months of such data following the final dose—the amount of safety data specified by the FDA in its guidance for potential Emergency Use Authorization—will be available by the third week of November.
Based on their current projections, Pfizer would be ready to manufacture globally up to 50 million vaccine doses at the end by the year and “up to 1.3 billion doses in 2021.”
Dr. Anthony Fauci, the director of the USA’s National Institute of Allergy and Infectious Diseases, described the trial results as “extraordinary” in an interview with the Washington Post, and said—given the US firm Moderna uses similar technology in its candidate vaccine—it, “gives you hope we might even have two vaccines.”