Britain on Monday became the first country to authorize a coronavirus vaccine that targets two variants, the original virus and Omicron, the variant that became dominant over the winter. Half of each dose of the Moderna-made vaccine will target the original variant, and the other half will target Omicron. InContinue Reading

In just eight weeks, the Omicron subvariant known as BA.5 has gone from a blip in United States case counts to the dominant version of the coronavirus in the country, now making up more than three-quarters of new cases. Perhaps the most transmissible subvariant yet, BA.5 is driving increases inContinue Reading

Although Vice President Kamala Harris was infected by the coronavirus in April, it’s not impossible that she could become infected again — a prospect raised by being with President Biden just two days before he tested positive. According to her schedule for that day, Ms. Harris received the president’s dailyContinue Reading

Barely six weeks after Shanghai fully lifted a prolonged and harshly enforced lockdown, China’s biggest city is again grappling with a surge of coronavirus cases. Residents wary of being suddenly confined in their homes have been alarmed by mixed messages from official sources circulating on social media, including advice thatContinue Reading

With coronavirus cases increasing in its immediate vicinity in Alaska, the vast Denali National Park and Preserve reimposed a mask mandate on Friday for federal buildings and on park buses. The National Park Service said the decision was made after community transmission of the coronavirus in Denali Borough, which includesContinue Reading

The rapidly spreading Omicron subvariants known as BA.4 and BA.5 are driving a summertime surge of the coronavirus in Europe, health officials say, after most Covid policies were removed in spring and a more relaxed approach to the pandemic has become the norm during the warmer months. Known cases inContinue Reading

Roseann Renouf, 77, has grown tired of the current generation of coronavirus shots. Having “never been one for a lot of vaccination,” she decided to forgo the latest round of boosters after watching vaccinated friends contract Covid-19, even though the doses offer a critical extra layer of protection. “It’s justContinue Reading

A new Chinese study about the relatively low risks associated with the Omicron variant of the coronavirus has reignited discussion about whether the country’s aggressive response to Covid-19 cases is necessary. The Chinese Center for Disease Control and Prevention on Saturday published a study that found that 22 of moreContinue Reading

Coronavirus infections surged in South Africa in recent months despite research suggesting that about 98 percent of the population had some antibodies from vaccination, previous infection, or both. The study, released Thursday but not yet peer reviewed, analyzed the prevalence of two types of antibodies in 3,395 blood donors collectedContinue Reading

Tests also differ in their sensitivity, and people differ in how they perform them. “Some people do a swab test and it’s like they barely touch their nose,” Dr. Gordon said. “Whereas with other individuals — actually, with a family member recently, I had to be like, ‘Don’t hurt yourself,’Continue Reading