Published June 29, 2021, 9:39 AM London, United Kingdom — Delayed second and third doses of the AstraZeneca vaccine boost immunity against COVID-19, a study by Oxford University, which developed the jab with the British-Swedish firm, said on Monday. An interval of up to 45 weeks between the first and second dose of the AstraZeneca vaccine led to an enhanced immune response, rather than compromising immunity, the study said. Vials of the Oxford-AstraZeneca COVID-19 vaccine are pictured at the Bangabandhu Sheikh Mujib Medical University Hospital (BSMMU), in Dhaka on June 22, 2021. (Munir Uz zaman / AFP / MANILA BULLETIN) Giving a third dose of the jab more than six months after the second dose also leads to a “substantial increase” in antibodies and induces a “strong boost” to subjects’ immune response, said the pre-print study, meaning that it has yet to be peer-reviewed.