Oxford study supports AstraZeneca for third dose against Omicron

A third dose of AstraZeneca's Covid vaccine, named Covishield in India, produces similar neutralising antibody levels against Omicron as after two doses against the Delta variant, according to a new study led by the Oxford University who developed the vaccine.

The yet-to-be peer-reviewed study showed that the levels of neutralisation titres for Omicron seen after the third dose booster were higher than the neutralising antibodies found in individuals who had been previously infected with and recovered naturally from Covid-19 Alpha, Beta, Delta variants and original strain.

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.

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 AstraZeneca vaccine, and 20 individuals that had received three doses of Pfizer.

"It is very encouraging to see that current vaccines have the potential to protect against Omicron following a third dose booster," said John Bell, Professor of Medicine at University of Oxford in a statement.

"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, said John Bell, Professor of Medicine at University of Oxford in a statement.

The drugmaker said researchers at Oxford University who carried out the study were independent from those who worked on developing the vaccine with AstraZeneca.

Meanwhile, Oxford University and AstraZeneca announced that they have begun the work to develop a Covid shot that specifically targets the new strain.

"Like with many previous variants of concern, and together with our partners AstraZeneca, we have taken preliminary steps in producing an updated vaccine in case it is needed," Sandy Douglas, a research group leader at Oxford, was quoted as saying to the Financial Times.