Timely booster jab effective in lowering risk of Omicron infection: HKU study

Timely Covid booster jabs are effective in reducing the frequencies of breakthrough infection and disease severity, according to an HKUMed study published in The Lancet.

The research team’s investigation found that a timely third-dose vaccination provided significant protection with lower incidence rates of breakthrough infections.

It said the third-dose vaccination activated spike (S)-specific memory B cells and Omicron cross-reactive T cell responses, which correlated with reduced frequencies of breakthrough infections and disease severity rather than with types of vaccines. 

Meanwhile, the study also found that tripled jabbed individuals could have enhanced cross-neutralizing antibodies to Omicron sublineages, including BA.2.12.1 and BA.4/5, after receiving a fourth dose with the bivalent vaccine.