Last Monday, November 9, drugmaker company Pfizer announced that its COVID-19 vaccine demonstrated 90% efficiency based on early studies. According to the analysis, 94 positive cases out of 43,000 volunteers who took two doses of the vaccine showed less than 10% of infection. Pfizer said that the vaccine reached its 90% efficiency seven days after the second shot was administered. This means that a person who takes the shots will be protected from the virus after 28 days. It is also required to have two doses of the vaccine for the immunization to take effect.

Since July 27, Pfizer has had approximately 43,538 participants for Pfizer’s Phase 3 trial and 38,955 out of the total number have received the second dose of the vaccine. Pfizer’s final goal is to reach 164 positive cases with its vaccine. The company also intends to check if the vaccine is effective enough to leave long-term protection even to those who had been infected before and recovered. According to Pfizer CEO Albert Bourla, it is still undecided if the shots are to be made yearly or seasonal.