Vaccination against COVID-19 does not prevent infection from the virus; however, it does significantly reduce the severity and reduces the risks of passing COVID-19 on to friends, family and colleagues.
A recent review in the medical journal The Lancet (“Risk factors and disease profile of post-vaccination SARS-CoV-2 infection in UK users of the COVID Symptom Study app: a prospective, community-based, nested, case-control study”) provides an indication of the level of risk reduction stemming from vaccination.
Medical data shows that a vaccination with one of the approved COVID-19 vaccines significantly reduces the severity and duration of symptoms. For example, 20 percent of people with COVID-19 experience multiple symptoms after vaccination. In contrast, this proportion within the population rises to 29 percent compared with those who have not been vaccinated.
Perhaps more importantly in relation to overall health, the risk of illness lasting for more than 28 days drops by over 50 percent in vaccinated individuals. A further telling statistic drawn out from the research is where the risk of hospitalisation after vaccination drops by 50 percent in 18 to 59 year-olds and by 82 percent in those aged over 60 years.
The research concludes that to minimise SARS-CoV-2 infection, those populations most at risk must be targeted so that overall community-related vaccine effectiveness rises. In the meantime, the study supports caution around relaxing social distancing and the necessity to continue with other personal protective measures in the post-vaccination era.
The main ‘at risk’ groups are frail older adults and citizens living in the more deprived areas. Going forwards, such areas and individuals should be considered as priorities for booster vaccinations.
There is a difference between ‘boosters’ and ‘third vaccine doses’. A booster is given to people who have received a full vaccine course to stop the immune response from waning over time. Third doses are being given to people who are immunocompromised and classed as especially vulnerable.
In terms of lowering the risk within the community, a study that features in the British Medical Journal (“Covid-19: One dose of vaccine cuts risk of passing on infection by as much as 50%, research shows”) establishes that the risk of passing on COVID-19 halves from an individual after that person has been vaccinated once.
Commenting on this, Deborah Dunn-Walters, the British Society for Immunology’s COVID-19 taskforce chair states: “While this study brings welcome news, we must not be complacent . . . It is still very important for us all to get two doses of the covid-19 vaccine to ensure we receive the optimal and longest lasting protection, both for ourselves and our communities.”
