Study shows COVID-19 vaccine is most effective within 6 months after vaccination

An analysis of more than 10 million COVID-19 cases by the UK's Health and Safety Executive found that vaccination significantly reduces the risk of death. The findings, published in the Journal of the Royal Society of Medicine, highlight the success of the vaccination program and the need for booster doses.

Research from the UK's Health Security Service shows that getting a COVID-19 vaccine significantly reduces the risk of death, especially in the six months after vaccination, highlighting the importance of boosting vaccination.

A new study has found that the risk of death is significantly reduced after receiving a COVID-19 vaccine, but that protection wears off after six months, providing evidence for continued booster shots.

Researchers from the UK Health Security Agency (UKHSA) analyzed more than 10 million adult COVID-19 cases between May 2020 and February 2022. Their findings were published in the Journal of the Royal Society of Medicine (JRSM).

Case fatality risk (CFR) - the proportion of cases that result in death - was cross-compared with vaccination status and showed a clear link between vaccination and reduced mortality. Notably, the study highlights a critical time period - the six months after the last dose of vaccine - where the risk of death from cases remains at its lowest across all age groups. Thereafter, the protective benefit begins to wane and the CFR begins to rise.

Research highlights the success of COVID-19 vaccination programs in reducing mortality.

Among adults over 50 years old, the CFR among those who had not been vaccinated (6.3%) was 10 times higher than among those who had been vaccinated within six months before testing positive (0.6%). The study also showed a sharp decline in CFR in early 2021, consistent with the early days of the vaccine rollout.

Florence Halford, of the COVID-19 Vaccine and Epidemiology Unit at the UK Health and Wellness Council, said: "The risk of death in COVID-19 cases is reduced after vaccination, with the lowest risk of death in cases of all ages when vaccinated six months before the specimen date. This provides some evidence for continued booster doses in older age groups."

Reference: Temporal changes in the risk of death in adults following COVID-19 vaccination in England between May 2020 and February 2022: a national surveillance study, by Florence Halford, Kathryn Yates, Tom Clare, Jamie Lopez-Bernal, Meaghan Kall and Hester Allen, December 13, 2023, Journal of the Royal Society of Medicine.

doi:10.1177/01410768231216332

Compiled source: ScitechDaily