At this first interim look 94 participants in the study has been infected by COVID-19. According to Pfizer, more than 90% of those infected received placebo and not the active vaccine. This strongly suggest that the vaccine has an effect in stopping the spread of the virus and keeping people from getting the potentially severe disease.

While no detailed safety data was reported, no serious adverse events were noted. When the median participant in study has been exposed to the vaccine for two months after the second dose, Pfizer will collect all safety data and submit for Emergency Use Authorization (EUA, an early type of drug/vaccine approval) to the US FDA. This should occur before the end of the year, perhaps as early as before the end of November, and if efficacy continues to hold up at that point FDA may grant EUA before the end of 2020.

While the news is undoubtably positive some caution should be given as the data is still early, the efficacy number may vary in coming interim readouts, we do not have solid long-term data of the vaccine yet and as mentioned above, the safety dataset is little known at this point. In addition, Pfizer need to massively scale up production of the vaccine to meeting global demand. We also soon expect data from Moderna, AstraZeneca and Johnson & Johnson on their respective COVID-19 vaccine candidates.