AstraZeneca Says First Dose of Its Covid-19 Vaccine Induces Immunity for at Least One Year

By Jaime Llinares Taboada

AstraZeneca PLC said Monday that trials on its Vaxzevria Covid-19 vaccine demonstrated strong immune responses following a prolonged second dose interval of up to 45 weeks.

The pharmaceutical company said antibody levels remain elevated for at least one year following a single dose.

AstraZeneca said a longer dosing interval isn't detrimental, but can derive stronger immunity as the level of antibodies were found to be four times higher with a 45-week dosing interval than with a 12-week interval.

A third dose given at least six months after the second boosted antibody levels six-fold, maintained T cell response, and resulted in neutralizing activity against the Alpha, Beta and Delta variants, it said.

"This should come as reassuring news to countries with lower supplies of the vaccine, who may be concerned about delays in providing second doses to their populations. There is an excellent response to a second dose, even after a 10 month delay from the first," said Andrew J Pollard, chief investigator and director of the Oxford Vaccine Group.

Shares in AstraZeneca at 1410 GMT were up 130 pence, or 1.5%, at 8,629 pence.

Write to Jaime Llinares Taboada at [e-mail]; @JaimeLlinaresT

(END) Dow Jones Newswires

June 28, 2021 10:32 ET (14:32 GMT)

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