A delayed second and third dose of the AstraZeneca vaccine results in a heightened immune response to COVID-19, according to an Oxford University study.
According to the research on the Oxford-AstraZeneca vaccine, a long interval between the first and second doses does not impair the immune response after a late second dose, and a third dose of the vaccine continues to boost antibodies against COVID-19.
Researchers investigating the effects of a 45-week delay between the first and second doses in study participants discovered that antibody levels increased after the delayed second dose.
“Additionally, a longer delay between first and second doses may be beneficial, resulting in an increased antibody titer and enhanced immune response after the second dose,” the University of Oxford said on Monday.
According to Professor Sir Andrew Pollard, Professor of Pediatric Infection and Immunity and Lead Investigator of the Oxford University vaccine trial, there is an excellent response to a second dose, even after a 10-month delay from the first jab.
The study also discovered that the incidence of side effects was lower after the second and third doses than after the first.
A third dose, which is also recommended, significantly boosts antibody titers as well as T-cell response and immune response against COVID-19 variants.
“It is not known if booster jabs will be needed due to waning immunity or to augment immunity against variants of concern,” Associate Professor Teresa Lambe OBE, lead senior author for these studies said on Monday. “Here we show that a third dose of ChAdOx1 nCoV-19 is well tolerated and significantly boosts the antibody response.”
The news comes as a relief to many countries, particularly those in Africa, which were facing a bleak vaccination road map due to a shortage of AstraZeneca vaccines manufactured in India.
The vaccine shortage caused by India’s pandemic crisis stranded poorer countries that relied on vaccines from the country’s serum institute.
Kenya which was scheduled to begin the second phase of the vaccination in May received 358,000 doses of the Oxford AstraZeneca vaccine from Denmark last Monday after supply ran out, causing concern among health care and other front-line workers.
