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
Study Details How Delta Variant Dodges Immune System
By Apoorva Mandavilli