AstraZeneca Covid booster increases antibodies against omicron – study

A third dose of AstraZeneca Covid-19 vaccine significantly boosted neutralising antibody levels against omicron, according to lab studies at the University of Oxford.

The vaccine, created by Astra and Oxford, saw neutralising antibodies increase to similar levels as those after two doses against the delta variant with a booster shot, the drug company said in a statement Thursday.

A third dose produced higher levels of neutralising antibodies than those found in individuals who had recovered naturally from the alpha, beta and delta strains of Covid-19, the company said.

The results are good news for the vaccine, which has been sidelined in the West as a booster shot after messenger RNA vaccines were shown to be more effective in various trials. The study looked at 41 people who had been given a third dose.

“It is very encouraging to see that current vaccines have the potential to protect against omicron following a third dose booster,” said John Bell, a professor of medicine at Oxford and one of the study investigators. “These results support the use of third dose boosters as part of national vaccine strategies, especially to limit the spread of variants of concern, including omicron.”

The data comes after Pfizer and Moderna released studies on how their vaccines stand up against omicron in recent weeks, as the variant surges across the world. Initial lab tests from Pfizer and partner BioNTech SE showed a third dose of their Covid-19 vaccine may be needed to neutralise the omicron variant after researchers observed a 25-fold reduction in neutralising antibodies that fight the variant from two doses.

Moderna also found a booster dose increased antibody levels against omicron, with the authorised 50 microgram third shot producing a 37-fold increase and a higher 100 microgram dose pushing antibody levels up 83-fold.