Pfizer's COVID-19 vaccine candidate offers protection after the first dose, according to documents released by the Food and Drug Administration Tuesday morning.
The information was made public ahead of a Thursday meeting of the Vaccines and Related Biological Products Advisory Committee, or VRBPAC — an advisory group to the FDA, which will vote on whether to advise the agency to grant emergency use authorization of the vaccine in the U.S.
The 53-page document contains analysis from both federal regulators and Pfizer on the latest data from the company's Phase 3 clinical trial on its COVID-19 vaccine. It will be used to help guide the advisory group in its decision making.
Based on the information provided in the document, Dr. Greg Poland, director of the Mayo Clinic's Vaccine Research Group in Rochester, Minnesota, said he could "see absolutely no reason why this emergency use authorization would not be granted." Poland is not involved in Pfizer's vaccine trials.
The Pfizer vaccine calls for two doses, three weeks apart. In November, Pfizer said early results from its Phase 3 clinical trials appeared to be 95 percent effective in preventing symptomatic COVID-19.
The new information shows it has benefits even after the first dose, with an effectiveness of more than 50 percent about a week later. What's more, the effectiveness seems to be the same across all age groups, racial and ethnic minorities, and people with underlying conditions, such as obesity, diabetes and high blood pressure.
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The shots may come with side effects, however, including fatigue, fever, headaches, muscle and joint pain.
Pfizer and its German partner BioNTech expects to have 50 million doses available this year and 1.3 billion in 2021, using facilities both in the United States and Belgium.
The United Kingdom was first to roll out the Pfizer vaccine. A 90-year-old woman near London was the receive the shot Tuesday morning.
This article originally appeared on NBCNews.com.