The BA.5 COVID Surge Is Here

A three-year-old getting her first dose of a COVID vaccine in Seattle last month. Photo: David Ryder/Getty Images

The newest wave of COVID infections and reinfections, fueled by more transmissible subvariants of the Omicron strain including BA.4 and BA.5, continues to grow across the U.S. The extra-worrisome BA. 5 is now the most dominant variant in the country, accounting for an estimated 53.6 percent of new infections last week, according to the CDC. As countless Americans gathered over the July 4 holiday weekend, it’s entirely possible that there were more new daily infections happening in the country than at any other point in the pandemic other than the Omicron wave. As BA.5 rapidly rises to what will likely be global dominance, the U.S. isn’t the only country experiencing a surge.

This week, the U.S. test positivity rate — which is now a more reliable indicator of case surges than official case counts — reached a seven-day average of over 17 percent for the first time since February 2.

The seven-day average test positivity rate for the U.S. through July 7, 2022. Illustration: Screencap/New York Times

As of July 8, New York City’s test positivity rate had climbed to 15.4 percent, the highest that metric has been since January 19. Last week, the city took down its color-coded COVID risk alert system; this week, Mayor Eric Adams called the system — which he introduced in March — an “old weapon” fighting an “old war.” He insisted the city’s COVID levels were “at a good, stable place,” explaining that “The numbers are ticking up … but we’re not at the place where our hospitals are over-impacted, and we’re not at a place where [we’re] stopping our growth in the city.”

It might be weeks before a replacement system is in place.

Seven-day average test positivity rate for New York City through June 27, 2022 Illustration: Screencap/New York Times

The CDC estimates that the level of community transmission remains high in more than 87 percent of U.S. counties, and remains substantial or higher in more than 95 percent of counties.

Illustration: Screencap/CDC

The good news? While U.S. COVID hospitalizations have been trending up since mid-April, they are nowhere near the levels reached in the Omicron wave, and the rates of new reported COVID deaths and COVID patients in intensive-care units are thus far only slightly ticking up and remain near pandemic lows. The vaccines are still doing an excellent job of preventing severe illness in most instances (and are finally now available for small children), and doctors have never had more tools to combat those severe illnesses when they do occur.

The bad news? Against these new subvariants, vaccines and prior infection are proving less and less effective at preventing infections and reinfections. They also appear to be at least somewhat less effective at preventing hospitalizations as the coronavirus evolves — particularly among the many un- and under-boosted seniors.

Daily number of people per 100,000 in the U.S. who were newly admitted to a hospital with COVID-19, grouped by age, according to HHS data. The top line is people 70 and older. Illustration: Screencap/HHS data/New York Times

A big wave of cases will be at best disruptive, will increase the risk of a lot more people developing long COVID, and will give SARS-CoV-2 many more opportunities to evolve. The full impact of multiple COVID reinfections, which many Americans already have or soon will experience, remains unclear. Most importantly, BA.5 may be the worst COVID variant yet. Its unique mutations make it the best equipped major variant to date at avoiding antibodies, which means it can likely reinfect people who recently had other Omicron subvariants. There is still a lot that scientists don’t know about the strain, and the threat of other even worse variants emerging remains very real. (BA.2.75, an Omicron subvariant recently detected in India, is the newest one to rapidly attract scientists’ attention.)

Estimated proportions of COVID variants in the U.S. through the week ending July 2, according to the CDC. Illustration: Screencap/CDC Nowcast

BA.5 and BA.4 continue to outcompete the other Omicron subvariants across the U.S. and BA.5 has quickly become the most dominant variant in the U.S. As of the week ending July 2, the CDC’s NowCast model estimates that BA.5 accounted for 53.6 percent of new infections nationwide, up from under 10 percent a month ago. BA.4 and BA.5 together comprised more than 70 percent of U.S. cases, and the previously dominant BA.2.12.1 continues to fade, after peaking at an estimated 63 percent of cases five weeks ago.

Overseas, the U.K. is experiencing a surge of new infections likely fueled by BA.4 and BA.5, as are many other countries. The tentative good news is that in most countries, the two variants haven’t thus far produced more severe outcomes, most likely thanks to the wall of immunity and hybrid immunity most people have at this point in the pandemic. But their evolutionary advantages remain concerning, and remain one of the major reasons why the current COVID wave is getting bigger, and may indeed last for a long time.

This post has been updated.

The BA.5 COVID Surge Is Here