The booster shot of the AstraZeneca’s Covid-19 vaccine gives significant boost to levels of antibodies against the Omicron variant, according to data from a new laboratory study. Performed independently by investigators at the University of Oxford, the study analysed blood samples taken from individuals infected with Covid-19; those who had been vaccinated with a two-dose schedule and a third dose booster; and those who had reported previous infection from other Covid-19 variants of concern. The study included samples from 41 individuals who had received three doses of the AstraZeneca vaccine. According to its findings, neutralisation titres for Omicron were boosted following a third dose with COVID-19 Vaccine AstraZeneca compared to titres after a second dose. “Sera obtained from individuals one month after receiving the third dose booster vaccination neutralised the Omicron variant to levels that were broadly similar to those observed one month after the second dose against the Delta variant,” read part of the statement from In addition, the levels of neutralising antibodies seen after the third dose booster were higher than those found in individuals who had been previously infected with and recovered naturally from Covid-19 (original strain, Alpha, Beta and Delta variants). Sir John Bell, Regius Professor of Medicine at the University of Oxford, one of the study investigators, said: “It is very encouraging to see that current vaccines have the potential to protect against Omicron following a third dose booster. 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.” Sir Mene Pangalos, the Executive Vice President for BioPharmaceuticals R&D at AstraZeneca said: “Covid-19 Vaccine AstraZeneca plays an important role in vaccination programmes around the world and these data give us confidence that the vaccine should be given as a third dose booster. It is also important to look beyond antibodies to better understand how vaccines offer protection against Omicron. As we better understand Omicron, we believe we will find that T-cell response provides durable protection against severe disease and hospitalisations.” Data from another laboratory study supported AstraZeneca’s effect against Omicron, with individuals vaccinated with two doses of the vaccine retaining neutralising activity against Omicron, although a decrease was seen compared to the original strain.
