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Pfizer COVID-19 Vaccine 90 Percent Effective, Review Says

Promising News: Initial Data Reports Pfizer's COVID-19 Vaccine Is 90% Effective

Pfizer reported on Monday, Nov. 9, that the COVID-19 vaccine research it has been spearheading with BioNTech since March shows promise; in the first formal review of its Phase 3 clinical trial, the vaccine was found to be more than 90 percent effective. Additionally, the companies said in a press release that the external, independent Data Monitoring Committee conducting the analysis also found zero serious safety concerns.

The vaccine is a two-dose vaccine administered about three weeks apart. It is mRNA based, meaning, as The New York Times explained, it "takes genetic material called messenger RNA and injects it into muscle cells, which treat it like instructions for building a protein — a protein found on the surface of the coronavirus. The proteins then stimulate the immune system and are believed to result in long-lasting protection against the virus."

The committee's analysis comes from 94 volunteers from the Phase 3 trial, which began in late July and has enrolled over 43,000 participants worldwide to date. The 94 people evaluated developed COVID-19 but had no evidence of prior infection, and we don't know which volunteers received the placebo and which received the vaccine. This data has not been published, let alone peer reviewed yet, and the initial 90-percent efficacy rate (at seven days after the second dose) could change as the trial continues on to its final analysis.

That being said, the FDA has stated vaccines need to have a minimum effectiveness rate of 50 percent. Pfizer said it will extend the trial until there is data from 164 coronavirus-infected people as opposed to the 94 initially evaluated. Another caveat: it's unclear how long immunity will last from the vaccine.

As the Phase 3 trial continues, it aims to evaluate the potential for the vaccine to protect against COVID-19 in people who had prior exposure to COVID-19 as well, the press release states, and aims to evaluate prevention against severe cases. Pfizer and BioNTech are expected to seek US emergency use authorisation later this month.

This makes Pfizer the first company to announce positive results from a vaccine this late in trials, according to The New York Times. Company executives have reportedly said that Pfizer will have manufactured enough doses by the end of the year to immunise up to 20 million people.

"We are reaching this critical milestone in our vaccine development program at a time when the world needs it most with infection rates setting new records, hospitals nearing over-capacity and economies struggling to reopen," Pfizer Chairman and CEO Albert Bourla, DVM, PhD, said in a statement. "With today's news, we are a significant step closer to providing people around the world with a much-needed breakthrough to help bring an end to this global health crisis."

POPSUGAR aims to give you the most accurate and up-to-date information about the coronavirus, but details and recommendations about this pandemic may have changed since publication. For the latest information on COVID-19, please check out resources from the WHO, the NHS, and GOV.UK.

Image Source: Getty / Karl Tapales
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