Ten month gap between AstraZeneca doses sees highest antibody boost: Oxford study

Study also reported reduced common adverse events after the second dose

Two doses of the AstraZeneca vaccine administered 44-45 weeks apart generated nearly four times the level of antibodies than when the doses were given 8-12 weeks apart, says a report by the Oxford Vaccine Group, the developers of the vaccine, on Monday. Antibody levels remained elevated for nearly a year and a third booster dose of the vaccine, given to a subset of volunteers, also significantly boosted antibody levels to twice that after a second dose. “A single dose of ChAdOx1 nCoV-19, with a second dose given after a prolonged period, may, therefore, be an effective strategy when vaccine supplies are scarce in the short term. A third dose results in a further increase in immune responses, including greater neutralisation of variant SARS-CoV-2 viruses, and could be used to increase vaccine efficacy against variants in vulnerable populations,” the authors report in a pre-print publication. This means the study is yet to peer-reviewed. A group of vaccine volunteers who got their second dose 15-25 weeks after the first, saw average antibody levels at nearly twice those in the 8-12 week interval, suggesting that lengthening the duration between doses appeared to be boosting antibody count.