“It makes us fear that this variant is already circulating quite widely in the country,” said Richard Lessells, an infectious disease specialist at the University of KwaZulu-Natal in Durban, South Africa, at the press conference of Thursday.
Dr de Oliveira warned that South Africa, where less than a quarter of the population is fully vaccinated, could see an increase in hospitalizations unless the country stops Omicron from multiplying further during events of super-spread. “We would really like to be wrong on some of these predictions,” he said.
Countries in Europe as well as the United States and Canada have been among those banning flights from South Africa and several other African countries. But Omicron has already been spotted in Hong Kong and Belgium, and may well be in other countries outside of Africa as well.
Theodora Hatziioannou, a virologist at Rockefeller University in New York, said the distinctive mutations in Omicron raise the possibility that it first evolved inside the body of an HIV-positive person, whose immune system was maybe too weak to fight it quickly. “Your answers are just not as good,” said Dr Hatziioannou.
Instead of being cleared within days, the virus may have lingered in that person for months, spending time gaining the ability to escape antibodies. “This virus has seen a lot of antibodies,” said Dr Hatziioannou.
Dr Hatziioannou and his colleagues were able to produce advanced mutant proteins in their laboratory that make viruses highly resistant to Covid-19 antibodies. She said Omicron had many mutations in the same regions of the spike protein identified in their own research. “The overlap is quite striking,” she said.
This overlap makes Dr Hatziioannou fear that Omicron may escape some of the antibodies people have acquired from vaccines or Covid-19 infections. Some monoclonal antibody treatments also won’t work against Omicron, she predicted, because the variant’s spike protein is protected from it.