Pfizer Vaccine Shows 90% Efficacy

The world cheered on Monday when Pfizer Inc announced its shot, jointly developed with BioNTech SE, was more than 90% effective based on initial trial results.

Important questions also remain. It’s unclear how long protection will last, as this study has only been underway for three months.

It’s unclear if this vaccine protects against severe disease or if this vaccine will work equally well in everyone.

Other important questions also remain. It’s unclear how long protection will last, as this study has only been underway for three months. It’s unclear if this vaccine protects against severe disease or if this vaccine will work equally well in everyone.