AstraZeneca vaccine highly effective at preventing COVID-19 severe outcomes and death when used as first or second booster: study
WHO recommends COVID-19 Vaccine AstraZeneca as booster in revised Good Practice Statement on the use of COVID-19 Boosters, based on latest data
BANGKOK - AstraZeneca's COVID-19 vaccine (ChAdOx1-S [Recombinant]) was highly effective at preventing Omicron-related COVID-19 severe outcomes or death when used as a first booster, irrespective of the type of vaccines previously given, with an 89% relative risk reduction. Following a second booster, protection increased further with no severe outcomes or death being observed. The data from Thailand’s Chiang Mai University and Chiang Mai Provincial Health Office, et al, was published in the International Journal of Infectious Diseases. In all schedules studied, a booster with COVID-19 Vaccine AstraZeneca was shown to offer comparable protection to mRNA vaccines.
Based on the latest data, including that from the Chiang Mai University, and following advice issued by the Strategic Advisory Group of Experts (SAGE) on immunisation, the World Health Organisation (WHO) has revised its Good Practice Statement on the use of COVID-19 boosters to include the use of viral vectored vaccines, including COVID-19 Vaccine AstraZeneca, as first or second boosters as part of any COVID-19 heterologous vaccination schedule.
WHO has also concluded that currently available data are not sufficient to support a preferential recommendation for bivalent variant-containing vaccine boosters over other currently available viral vector and mRNA vaccine boosters.
Data from an earlier analysis of the same data set, posted as a preprint in Research Square, show that a first booster with COVID-19 Vaccine AstraZeneca was also effective at preventing COVID-19 infections due to Omicron, offering comparable protection to mRNA vaccines.
Emeritus Professor Suwat Chariyalertsak, MD, Dr.PH, Faculty of Public Health, Chiang Mai University, Thailand, commenting on the data produced in collaboration with the Chiang Mai Provincial Health Office, said: “Our studies provide important data showing that COVID-19 Vaccine AstraZeneca and mRNA vaccines are both effective as first or second boosters in reducing the risk of Omicron-related severe COVID-19 or death when used as part of a heterologous schedule. Adopting a heterologous, or ‘mix and match’, vaccination schedule may help enhance ongoing efforts to increase population coverage of booster doses.”
John Perez, Senior Vice President, Head of Late Development, Vaccines & Immune Therapies, AstraZeneca, added: “These new data further support our expectation that additional boosters of COVID-19 Vaccine AstraZeneca can help protect against all severities of Omicron-related COVID-19 from mild symptomatic to severe disease including hospitalisation and death. COVID-19 Vaccine AstraZeneca will continue to play an important role in helping to protect against currently-circulating COVID-19 variants as part of a primary or booster vaccination schedule.”
To date, over 3 billion doses of COVID-19 Vaccine AstraZeneca have been released for supply to more than 180 countries around the world, of which over two thirds have gone to lower- or lower-middle income countries. Based on model outcomes, COVID-19 Vaccine AstraZeneca is estimated to have helped save over 6 million lives during its first year of use.
