Covid-19: T-cells to rescue as Omicron can't escape it, show studies

An unsung arm of the immune system appears to protect against severe disease with the Omicron variant even when antibodies wane, helping to explain why a record wave of infections hasn’t engulfed hospitals so far.

T cells, the body’s weapon against virus-infected cells, were primed enough by vaccination that they defended against omicron in separate studies from Erasmus University in the Netherlands and the University of Cape Town in South Africa. 

The study from the University of Cape Town’s Institute of Infectious Disease and Molecular Medicine looked at patients who had recovered from Covid or been vaccinated with shots from Pfizer Inc. and partner BioNTech SE or Johnson & Johnson. They found that 70 per cent to 80 per cent of the T cell responses they assessed held up against Omicron.

The number of Covid-19 cases topped one million globally for the third day in a row, as the World Health Organization warned of a “bumpy road” ahead. 

Experts in Singapore, which is seeing a surge in Omicron cases, warned that the new and supposedly more contagious variant is likely to replace Delta over the coming weeks as the dominant global variant, with the virus being fitter and having a reproductive advantage.

A booster dose of Johnson & Johnson’s single-dose Covid-19 vaccine was 84 per cent effective at preventing hospitalisation in South African healthcare workers who became infected as the Omicron variant spread, researchers said on Thursday.

The real-world study, which has not been peer-reviewed, was based on a second dose of the J&J vaccine administered to 69,092 healthcare workers between November 15 and December 20.

In the US, virus deaths are declining even as cases rise, according to federal health officials who suggested the surging Omicron variant may cause less suffering than other strains. Cases involving the Omicron variant will likely peak by the end of January, presidential medical adviser Anthony Fauci said.

England’s National Health Service is building temporary structures at hospitals around the country to prepare for a possible surge of Covid-19 patients as the highly transmissible omicron variant fuels a new wave of infections.

The UK reported a record 183,037 confirmed new coronavirus infections on Wednesday, 32 per cent more than the previous day. 

JetBlue Airways said it was reducing its schedule through January 13 by about 1,280 flights due to a surge in crew members falling sick from the Omicron variant, a spokesperson for the airline told Reuters on Thursday.

Italy, meanwhile, eased coronavirus quarantine rules and imposed a vaccine mandate for most activities in a bid to keep essential services running, after the country recorded a record number of cases for consecutive days.

Mario Draghi’s government lifted its quarantine requirement completely for people who come into contact with a Covid-19 case as long as they have had three vaccine doses, according to a statement.