Scientists say Omicron spreading twice as quickly as Delta in South Africa

The omicron variant of the coronavirus is spreading twice as quickly as the delta variant and may be three times as likely to reinfect those that have already recovered from Covid-19, according to a pair of preliminary studies out of South Africa this week.

Key Facts

Preliminary data from nine South African provinces shows the omicron variant has spread more than twice as quickly as the delta variant, according to South African Covid-19 Modelling Consortium figures shared on Twitter Friday by London School of Hygiene & Tropical Medicine mathematical modeler Carl Pearson, though the data has not been peer-reviewed or published in a scientific journal.

Pearson told the New York Times researchers aren’t sure whether the omicron variant’s quick spread is primarily due to its contagiousness or an ability to evade the immune system, adding, “It’s possible that it might even be less transmissible than Delta.”

South African researchers also estimated Thursday that omicron is at least three times more likely to reinfect people who have recovered from a Covid infection than previous variants, citing a large increase in the rate of coronavirus reinfection during the country’s most recent wave, according to a non-peer-reviewed preprint article.

The omicron variant accounted for 73% of all sequenced genomes from positive Covid-19 tests in South Africa in the month of November, according to the country’s National Institute For Communicable Diseases, though only a small fraction of samples from tests are sequenced each week.

Crucial Quote

“The studies appear to illustrate what we’ve been seeing anecdotally come out of the data from South Africa,” Dr. Amesh Adalja, senior scholar at Johns Hopkins University’s Center for Health Security at the Bloomberg School of Public Health, told Forbes. “This variant has the ability to transmit efficiently and has the ability to cause reinfections at a higher rate than we’ve seen with other variants.”

Big Number

16,055. That’s how many new Covid-19 cases South Africa reported on Friday, jumping from 11,535 on Thursday and 8,561 on Wednesday.

Forbes