According to the World Health Organization's most recent report, it was behind 52% of cases sequenced in late June, up from 37% in one week. In the United States, it is approximated to be causing around 65% of infections.
BA.5 is not unknown. First identified in January, it has been followed by the WHO since April.
It is a sister of the Omicron variant that has been dominant worldwide since the end of 2021 and has already brought spikes in case rates – even with reduced testing – in countries including South Africa, where it was first found, as well as the United Kingdom, parts of Europe, and Australia.
WATCH: BRITAIN'S HEAVIEST MAN HAS PASSED AWAY AT 33
Coronavirus cases worldwide have now been increasing for four weeks in a row, WHO data showed.
Like its closely affiliated sibling, BA.4, BA.5 is particularly good at avoiding the immune protection provided either by vaccination or previous infection.
PASTOR DODGES BULLET MID-SERMON AFTER MAN "SEES SPIRITS" AND OPENS FIRE
For this reason, "BA.5 has a growth advantage over the other sublineages of omicron that are circulating," Maria Van Kerkhove, the WHO's technical lead on COVID-19, told a news briefing on Tuesday. For many people, this means they are getting re-infected, often even a short time after COVID-19. Van Kerkhove said the WHO is assessing reports of re-infections.
WATCH: AT WHAT POINT WE WILL TAKE THEM SERIOUSLY?
"We have ample evidence that people who've been infected with omicron are getting infected with BA.5. No question about it," said Gregory Poland, a virologist and vaccine researcher with the Mayo Clinic in Rochester, Minnesota.
If that seems quite common now, it could be simply because so many people got Omicron, researchers have suggested.
While surging cases have caused more hospitalizations in some countries, deaths have not gone up dramatically.
JOHN FETTERMAN BELIEVES CAMPUS PROTESTS ARE "WORKING AGAINST PEACE" IN THE MIDDLE EAST
This is virtual because vaccines continue to protect against severe illness and death if not infection. Manufacturers and regulators are also looking at tweaked vaccines targeting the newer omicron variants.
MAN'S UNEXPECTED CONFESSION ON SIDE OF OKLAHOMA HIGHWAY SHAKES UP 5-YEAR-OLD COLD CASE
There is also no proof that BA.5 is more hazardous than any of the other Omicron variants, the WHO's Van Kerkhove stressed, although spikes in cases can put health services under pressure and risk more people getting long COVID.
The WHO and other experts have also said that the continuing pandemic - prolonged by vaccine inequity and the desire in many countries to "move beyond" COVID-19 – would only direct to more new and unpredictable variants.
TARGETING DISSIDENTS: THEY ESCAPED THEIR HOMELANDS, BUT DANGER STILL LOOMS FOR THEM HERE, FBI SAYS
Scientists are already drawing attention to BA.2.75, first identified in India, which has many mutations and is spreading fast. The WHO said on Tuesday that the pandemic remained a global health emergency, and countries should consider public health measures like masking and social distancing when cases surge, alongside vaccinations.
MORE CHINESE NATIONALS CAUGHT CROSSING U.S. BORDER IN 2 DAYS THAN ALL OF 2021
"What people fundamentally don't understand is that when there is this high level of community transmission, this will mutate," Poland said. "Who knows what's going to come next. We are playing with fire."
Some 31,000 people across the U.S. are hospitalized with the virus, with entries up 4.5% compared to a week ago. And data from New York state shows that reinfections started trending upwards again in late June.
Dr. Bob Wachter, the chair of the Department of Medicine at the University of California, San Francisco, says BA.5 is highly transmissible and manages to sidestep at least partially some of the immunity people may have from prior infections and vaccinations.
MEDIA FRENZY: ABC NEWS PRESIDENT KIM GODWIN STEPS DOWN, TRUMP RESPONDS
"Not only is it more infectious, but your prior immunity doesn't count for as much as it used to," he explains. "And that means that the old saw, 'I just had COVID a month ago, and so I have COVID immunity superpowers, I'm not going to get it again' — that no longer holds."
Discover alternative ideas that will make you think
Engage in mind bending debate
Earn points, rise in rank, have fun
