Scientists are closely tracking a coronavirus variant with a 'worrying' number of mutations. They don't yet know if it's more infectious.

• A new coronavirus variant has been detected in South Africa, Botswana, and Hong Kong.
• Experts fear its mutations may help it avoid antibodies produced by vaccines and treatments.

Scientists and health officials are closely tracking a coronavirus variant with a "worrying" number of mutations that has been detected in South Africa, Botswana, and Hong Kong.

The variant, called B.1.1.529, has 32 mutations in the part of the virus that attaches to human cells, called the spike protein — the target for existing vaccines and antibody treatments. A higher number of mutations in the spike protein may change its shape and means there is a greater risk those vaccines and treatments won't be as effective against it.

Experts are worried the mutations might make the virus more infectious and help it avoid the antibody response, but this hasn't been proved. It's also not clear whether the mutations make the virus more deadly.

COVID-19 vaccines remain a "critical tool" to protect against severe illness, Tulio de Oliveira, the director at South Africa's Centre for Epidemic Response and Innovation, said in a briefing Thursday.

Tom Peacock, a virologist at Imperial College London who posted about the variant on GitHub on Tuesday, said the high number of mutations could be of "real concern" and there were combinations of mutations he hadn't seen before in a single variant of the virus that causes COVID-19.

Francois Balloux, the director at the University College London Genetics Institute, said in a statement to the Science Media Center on Wednesday that the fact such a large number of mutations appeared to have occurred in a single burst suggested the variant evolved from a chronic infection in an immunocompromised person.

B.1.1.529 was first detected November 11 and has been sequenced 82 times — 77 cases in South Africa, four cases in the neighboring Botswana, and one case in Hong Kong. The Hong Kong case was attributed to a person who had traveled to South Africa, according to South Africa's National Institute for Communicable Diseases on Thursday.

Peacock cautioned that the "export to Asia" might suggest it's already more widespread than the sequences imply.

Adrian Puren, the acting executive director at the NICD, said in a statement Thursday that NICD experts were "working overtime" to understand the new variant and its implications.

Ravi Gupta, a professor of clinical microbiology at Cambridge University, said on Twitter on Wednesday that the B.1.1.529 variant was "worrying, and I've not said that since Delta." The highly infectious Delta variant, which is the most common variant worldwide, has 11 to 15 mutations in its spike protein, and some of them help it avoid the immune response, according to the Centers for Disease Control and Prevention.

"Please get vaccinated and boosted and mask up in public as the mutations in this virus likely result in high level escape from neutralising antibodies," Gupta said.

Dr. Michelle Groome, the head of the division of public-health surveillance and response at the NICD, said individual compliance to preventive measures could have a "great collective impact" in limiting the spread of the new variant. "This means that individuals should get vaccinated, wear masks, practice healthy hand hygiene, maintain social distancing, and gather in well ventilated spaces," she said.

The World Health Organization and health officials from South Africa, where most of the cases have been detected, are due to meet to discuss the variant Friday.