Top SA scientist warns Omicron may be easier to spread

The new coronavirus variant, Omicron, appears to be more transmissible than earlier lineages and is likely to send the reported number of daily cases surging past 10,000 by the end of the week, one of SA’s top scientists said on Monday.

The current seven-day moving average of new cases stands at about 1,640, according to Our World in Data.

Omicron was detected in Botswana and SA last week and has since been identified in at least 10 other countries. It has dozens of mutations, many of which are present in other variants of concern and are associated with increased transmissibility, said University of KwaZulu-Natal epidemiologist Salim Abdool Karim, former co-chair of the health minister’s Covid advisory committee.

The detection of Omicron has coincided with an extremely rapid increase in cases and hospital admissions in Gauteng since mid-November, adding weight to scientists’ concerns about the new variant’s potential to drive new infections.

"I’m expecting we will top 10,000 cases per day by the end of the week, and [see] pressure on hospitals within the next two to three weeks because of the rapidity of transmission," Karim said in a virtual briefing led by health minister Joe Phaahla.

Scientists from the National Institute for Communicable Diseases (NICD) said the average number of daily hospital admissions had risen sharply in Gauteng, almost tripling in the fortnight to November 27 to 49 per day, compared with 18 per day in the previous 14 days.

While these numbers are still low relative to the peaks of SA’s three previous waves, the speed with which the numbers are rising is worrying scientists. Daily hospital admissions in Gauteng peaked at 941 during the peak of SA’s third wave in July.

"Admissions always lag a week or two [behind new cases], but we can already see a very sharp rise in both the public and private sector," said NICD scientist Waasila Jassat. All five districts in Gauteng show rising hospital admissions, with the biggest jump in Tshwane.

The "vast majority" of Covid-19 patients recently admitted to hospital were unvaccinated, and most were younger adults.

Karim said Covid-19 vaccines are likely to retain their protection against severe disease caused by Omicron, but it is unclear at this stage whether they would be less effective at preventing transmission compared with other variants, such as Delta, which drove SA’s third wave of infections.

A little more than a third (35.6%) of SA’s adults are fully vaccinated, with either two doses of the Pfizer/BioNTech vaccine or a single dose of the Johnson & Johnson jab.

Nicholas Crisp, acting health director-general, said the government was considering rolling out booster shots, starting with older people, many of whom received shots six months ago.

SA began its mass vaccination programme on May 17, and at that stage, had only Pfizer supplies on hand. Providing booster shots will need approval from the SA Health Products Regulatory Authority, which is considering an application from Pfizer, Crisp said.

Many governments have imposed travel bans on SA and other Southern African countries to try to stop the spread of Omicron. But Karim said closing borders would do little to contain the new variant, and it would be far better for countries to focus on tried-and-tested public health measures for slowing the spread of Covid-19 among travellers.

These include vaccination, testing and symptom screening before departure, wearing masks, and testing upon arrival, Karim said.

kahnt@businesslive.co.za