Around the world, the latest Omicron subvariant, BA.5, is quickly becoming the dominant strain of the SARS-CoV-2 virus. Indeed, it just took the top spot in the U.S.: As of the last week of June, BA.5 made up more than half of all new COVID-19 cases, according to new estimates from the U.S. Centers for Disease Control and Prevention (CDC). That’s up 10 percentage points compared to the prior week.
For several reasons—including a lack of protective mandates and mutations in the virus—BA.5 may now be tricky to get under control.
The power of BA.5 (and its sibling BA.4, which makes up about 16% of new cases, has the same spike protein mutation as BA.5, but doesn’t seem to spread as quickly) is its ability to infect, and reinfect, almost anyone. This highly contagious strain is able to evade people’s built-up immunity, whether from vaccination or previous infection. As Nature reports , lab studies show that even people who have so-called “hybrid immunity” from vaccination and a past infection with the Omicron BA.1 strain are less able to ward off reinfection from either the BA.4 or BA.5 strains. Experts believe this is due largely to changes in the virus’ spike proteins. Current COVID-19 vaccines and boosters target the original strain of the virus rather than any of the variants, so being vaccinated doesn’t offer as much protection as it once did against infection. (Luckily, the vaccines still confer broad protection against the worst outcomes of the disease.)
Since BA.4 and BA.5 have taken over, "we have seen some cases of reinfection,” Dr. Wesley Long, an experimental pathologist at Houston Methodist Hospital, told CNN, “and I have seen some cases of reinfection with people who had a BA.2 variant in the last few months."
Combine the virus’ greater transmissibility and more immune evasion with fewer protective mandates across the country, the threat of infection is high. Conditions are also ripe for new variants to emerge, since the risk of mutation increases the more the virus spreads. On top of this, recent research (which has yet to be peer reviewed) found that people who had been reinfected with COVID-19 had a higher risk of hospitalization and death than people who had just been infected once. They were also more likely to develop new and lasting health impacts, including lung and heart problems, fatigue, digestive and kidney disorders, diabetes, and neurologic problems.
Vaccine manufacturers are trying to keep up with the virus. On June 30, the U.S. Food and Drug Administration (FDA) said that new booster shots for the fall must target BA.4 and BA.5. But while companies are developing new vaccines to specifically address Omicron, it’s still unclear how effective they will be in tackling the more recent subvariants, or, if the virus keeps evolving so rapidly, whether anything developed now will be outdated by the time it’s available.
The hopeful news is that from what experts can tell so far, the BA.5 variant isn’t causing a more severe form of infection (although scientists are still gathering more data on this), the reported symptoms haven’t changed much, and death and hospitalization rates in the U.S. are lower than they were during the winter Omicron wave. (This could change, however, as there appears to be a slight uptick in hospitalizations, according to the CDC.)
In the meantime, experts recommend that people over 50 not delay getting their boosters, since the risk of infection right now is high.
TODAY'S CORONAVIRUS OUTLOOK
More than 550 million people around the world had been diagnosed with COVID-19 as of 3 a.m. E.T. today, and more than 6.3 million people have died. On July 4, there were 851,037 new cases and 1,034 new deaths confirmed globally.
Here's how the world as a whole is currently trending, in terms of cases:
And in terms of deaths:
Here's where daily cases have risen or fallen over the last 14 days, shown in confirmed cases per 100,000 residents:
And here's every country that has reported over 10 million cases:
The U.S. had recorded more than 87.8 million coronavirus cases as of 3 a.m. E.T. today. More than 1 million people have died. On July 4, 43,028 new cases were reported and 67 new deaths were confirmed in the U.S.
Here's how the country as a whole is currently trending in terms of cases:
And in terms of deaths:
Here's where daily cases have risen or fallen over the last 14 days, shown in confirmed cases per 100,000 residents:
All numbers unless otherwise specified are from the Johns Hopkins University Center for Systems Science and Engineering, and are accurate as of July 5, 12 a.m. E.T. To see larger, interactive versions of these maps and charts, click here.
Have suggestions for our COVID-19 newsletter? We'd love to hear from you. Fill out our survey here.
WHAT ELSE YOU SHOULD KNOW
Between March 2020 and October 2021, COVID-19 was the third leading cause of death in the U.S., after heart disease and cancer. That’s according to new analysis by the National Cancer Institute, which is part of the National Institutes of Health. During that time period, COVID-19 accounted for 1 in 8 deaths—350,000 in total—in the country.
While many parents welcomed the news last month that children under five could finally get vaccinated, others remain hesitant. But there are good reasons to vaccinate the youngest Americans, my colleague Alice Park reports.
New York City is the first place in the U.S. to offer free, immediate Paxlovid prescriptions at mobile testing centers for people who test positive, the New York Times reports. The aim is to help increase access to the antiviral treatment for people who may not have a primary care doctor or insurance, or who don't know about the treatment.
Thanks for reading. We hope you find the Coronavirus Brief newsletter to be a helpful tool to navigate this very complex situation, and welcome feedback at coronavirus.brief@time.com. If you have specific questions you'd like us to answer, please send them to covidquestions@time.com.
If you were forwarded this and want to sign up to receive it twice a week on Mondays and Thursdays, click here.
Today's newsletter was written by Kyla Mandel and edited by Mandy Oaklander.
沒有留言:
張貼留言