Booster vaccines significantly reduced the risk of hospitalisation and death related to COVID-19 for adults in England during the autumn 2022 booster campaign, according to a new study published today in the journal Vaccine. The research, led by the universities of Bristol and Oxford, provides further evidence supporting the effectiveness of booster vaccinations against the virus.
The study, conducted by researchers at the National Institute for Health and Care Research (NIHR) Bristol Biomedical Research Centre (BRC), analysed data from over 3.4 million adults aged 50 and over who received a booster vaccine during the autumn 2022 rollout. Researchers compared these individuals with a matched group of over 3.4 million unboosted adults, controlling for factors such as age, time since last COVID-19 vaccine, prior vaccine brand, clinical vulnerability, and geographical location.
Using linked GP and hospital records within the OpenSAFELY research platform, the team tracked hospitalisations and deaths due to COVID-19 for nearly a year. The analysis revealed that boosted individuals experienced a 350-day risk of COVID-19 hospitalisation of 3.78 per 1,000 people, compared to 6.81 per 1,000 in the unboosted group. The risk of COVID-19 related death was also substantially lower for those who received a booster, at 0.29 per 1,000, versus 0.61 per 1,000 for the unboosted.
The study found that booster vaccines approximately halved the risks of both COVID-19 hospitalisation and death. Protection was strongest within the first 70 days after vaccination, with effectiveness waning over time. The Moderna (BA.1 mRNA-1273) and Pfizer-BioNTech (BA.1 BNT162b2) booster vaccines demonstrated similar performance in preventing COVID-19 related hospitalisations and deaths.
Researchers also observed a slightly higher rate of non-COVID-19 mortality in the group receiving the Moderna vaccine. But, the study also assessed fracture risk – an outcome not expected to be directly linked to vaccination – and found a small reduction in fractures among boosted individuals. Researchers noted this suggests that some confounding factors may not have been fully accounted for, but the limited effect on fracture risk supports the overall validity of the study’s findings.
“Our findings reinforce the importance of booster vaccination against COVID-19 among people over 50 years old,” said Dr. Paul Madley-Dowd, Research Fellow in Medical Statistics and Health Data Science at the University of Bristol, and the study’s corresponding author. “The study also provides further evidence that COVID-19 booster vaccinations reduced the risk of hospitalisation and death.”
The research was funded by NHS England, the Wellcome Trust, the Medical Research Council (MRC), the NIHR, the NIHR Bristol BRC, OpenSAFELY, and the Bennett Institute for Applied Data Science.
Moderna UK was established within nine months during the pandemic to ensure supply of the COVID-19 vaccine, according to Darius Hughes, General Manager of Moderna United Kingdom. The company aims to leverage mRNA technology to develop a new generation of medicines.
Spikevax, formerly known as the COVID-19 Vaccine Moderna, was initially approved by the Medicines and Healthcare products Regulatory Agency (MHRA) on January 8, 2021, and the Summary of Product Characteristics has been updated as recently as September 15, 2023. Spikevax JN.1 is currently indicated for active immunisation to prevent COVID-19 caused by SARS-CoV-2 in individuals 6 months of age and older.
