Duration of the efficacy of the Pfizer-BioNTech mRNA vaccine

According to information from Pfizer-BioNTech, the results of monitoring the efficacy of the COVID-19 vaccine trial,
at the six-month point, show that the vaccine remains highly effective. The manufacturers indicated that six months
after the second dose, or possibly longer, the vaccine remains effective in more than 91% of vaccinated individuals.

Of the 927 symptomatic cases of COVID-19 confirmed in the study, 850 cases of COVID-19 occurred in the placebo
group, while there were 77 cases in the vaccinated group, representing 91.3% efficacy (95% CI, 89.0%-93.2%).

In addition, the results suggest that the vaccine is effective against variant B.1.351 of the virus, the dominant strain in
South Africa, which was thought to have evolved to evade vaccine protection. This information must be evaluated
and confirmed by the regulatory authorities.

Source: Pfizer and BioNTech confirm high efficacy and no serious safety concerns for up to six months following
second dose in updated topline analysis of landmark COVID-19 vaccine study. 1 April 2021.