With an uptick in Covid-19 cases, there is growing alarm. 'We've seen almost an entire takeover in the Delta variant,' one state official says
By Aya Elamroussi
Study shows booster shot after 6 to 12 months likely to provide best protection from COVID-19, Pfizer says
By Eric M. Strauss & Mark Osborne
Yes, you can still get COVID after being vaccinated, but you're unlikely to get as sick
By Lara J. Herrero