Risk of death from Covid-19 decreases post-vaccination but wanes after six months, reveals study

A new study has found the risk of death from Covid-19 decreases significantly after vaccination but this protection diminishes after six months, highlighting the need for ongoing booster doses.

The recent study was conducted by researchers at the UK Health Security Agency (UKHSA) and delved into over 10 million Covid-19 cases among adults between May 2020 and February 2022.

Their findings, published in the Journal of the Royal Society of Medicine (JRSM), revealed a noteworthy correlation between vaccination and reduced mortality rates, with a significant decline in the Case Fatality Risk (CFR) among vaccinated individuals.

Interestingly, the study identified a critical window of protection within six months of the last vaccine dose, during which CFR consistently remained at its lowest across all age brackets.

However, beyond this timeframe, the protective effect of the vaccine showed signs of waning, leading to an increase in CFR.

Therefore, this research emphasised the success of the Covid -19 vaccination programme in mitigating mortality rates.

Particularly among adults aged over 50, the CFR was notably higher in the unvaccinated group (6.3%) compared to those vaccinated within six months before testing positive (0.6%).

Additionally, the study observed a sharp decline in CFR in early 2021, coinciding with the initial stages of the vaccine rollout.

Florence Halford, from the UKHSA’s Covid -19 Vaccines and Epidemiology Division, said, " Covid -19 Case Fatality Risk reduced after vaccination, with the lowest seen across all age bands when vaccinated up to six months prior to the specimen date. This provides some evidence for continued booster doses in older age groups."