The recently detected BA.2.86 variant of Covid-19 could be more likely to cause infections in those who have already been vaccinated or infected than older variants, the Centers for Disease Control and Prevention (CDC) announced Wednesday.
However, the CDC said it was too soon to know if this will cause more severe infection than other variants.
But due to the high number of mutations detected in this lineage, there were concerns about its impact on immunity from vaccines and previous infections.
‘Nearly all the U.S. population has antibodies to SARS-CoV-2 from vaccination, previous infection, or both, and it is likely that these antibodies will continue to provide some protection against severe disease from this variant,’ the agency said.
The announcement comes as two Americans have tested positive for BA.2.86, and cases of another new variant, EG.5, or Eris, are on the rise.
The above graph shows the percent of positive Covid cases (tan line) and the weekly number of new Covid hospitalizations (blue bars)
Americans wear face masks as they wait in line to vote in the 2020 presidential election. Some colleges and businesses are reinstating mask mandates as Covid cases rise in the US
However, the CDC said the current increase in US hospitalizations is not likely driven by BA.2.86.
The most recently updated Covid vaccines are targeted toward strains from the variant XBB Omicron. However, BA.286 has many more mutations, with the CDC comparing it to something similar to the delta and Omicron variants.
‘The large number of mutations in this variant raises concerns of greater escape from existing immunity from vaccines and previous infections compared with other recent variants,’ the CDC said.
‘For example, one analysis of mutations suggests the difference may be as large as or greater than that between BA.2 and XBB.1.5, which circulated nearly a year apart.’
The test positivity rate in the US — the share of swabs that come back positive — has soared from one in 15 in the week ending July 15 to one in eight by August 12, according to the latest CDC data.
It means test positivity is at its highest level in more than a year. In several states, including Texas, Arkansas and Louisiana, one in six Covid swabs came back positive in the most recent week.
Because regular Americans are no longer testing en masse like they were at earlier points in the pandemic — just 40,000 swabs are being reported to the CDC each week — it has become more difficult to spot new outbreaks early.
But all metrics indicate infections are rising rapidly.
The above map shows the percent positivity rate in each state over the past week. In several states, including Texas, Arkansas and Louisiana, one in six Covid swabs came back positive in the most recent week
The above chart shows Covid variants in the United States. It highlights how EG.5, an emerging variant, has grown rapidly across the country
From July 15 to August 12, hospitalizations rose from 7,175 to 12,613, though they still remain three times lower than this time last year.
That concern, combined with an uptick in positive tests across the US, has spooked an Atlanta college and the Hollywood studio Lionsgate into mandating face masks again.
But while Covid rates are rising in the US — hospital admissions are up for the fifth week in a row — they remain at near-historic lows.
Test positivity — the share of tests that come back positive for the virus — has doubled in the US in the past month and searches for Covid symptoms on Google have spiked in the past few weeks.
Lionsgate studios asks office staff to don face coverings and test again as Covid hospital rates rise for fifth week
A major Hollywood studio has reintroduced Covid mask mandates amid fears about rising virus rates and a new highly mutated variant
But doctors on the ground say that while they are seeing an increase in patients with the virus, their symptoms are milder than at any point previously in the pandemic.
Dr Aaron Glatt, a medic at Mount Sinai in New York City, said the fact that two cases had been confirmed in the US signaled there are ‘many more’ not being picked up.
Asked whether there were more cases of BA.2.86 in the US, he previously told DailyMail.com: ‘This is certainly very possible. It would be surprising if it didn’t spread.’
On the number of cases already in the US, he said: ‘It’s certainly possible that there are tens of cases, and it is certainly very possible that there are more.
‘The only question is how important that is. Does this variant have a survival advantage over other strains?’
Its ability to evade vaccines might be that advantage.
So far three other countries — Israel, Denmark and the UK — have detected the strain, but most countries don’t have the infrastructure to pick up on new variants.
The new variant is yet to be detected in Japan, but official data from the country shows that cases and hospitalizations are rising.
Latest data shows there were 22,000 Covid patients in the country’s hospitals on August 16, which was double the 10,000 from the week before.
This was, however, still below the 35,000 reported at the same time last year.
The Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) have both said they are tracking the mutant strain.
This weekend, former Food and Drug Administration (FDA) commissioner Dr Scott Gottlieb also voiced alarm, saying he was ‘pretty concerned’ by the new strain and that it may well be more transmissible than other variants that are currently circulating.
However, doctors are still advising Americans to hold off getting a booster vaccine, despite these surging cases.
Dr Jennifer Nuzzo, director of the pandemic center at Brown University School of Public Health, told ABC News: ‘Reasonably at this point, if you’re not high risk and do not have high exposures, waiting a few weeks to get the updated shot should be okay.