A nurse administers a coronavirus vaccine to 15-year-old Lara Sofia in Gran Canaria, Spain, on July 28, 2021. Borja Suarez / Reuters
A nurse administers a coronavirus vaccine to 15-year-old Lara Sofia in Gran Canaria, Spain, on July 28, 2021. Borja Suarez / Reuters
Pfizer vaccine protection against Covid-19 reduced after four months
Research released as company seeks approval for boosters
