However, people living in most deprived areas were at greater risk of infection after a single vaccination. While age on its own was not a risk factor, individuals who had health conditions that limited their independence – such as frailty - were up to two times more likely to contract COVID-19 infection after vaccination, and of getting sick.
The findings demonstrate the need to target at-risk groups. Frail adults have already been shown to be disproportionately affected by COVID-19. The research team suggests strategies such as a timely booster programme, targeted infection control measures and more research into the immune response to vaccination in this group could help address the issue.
Lead researcher Dr Claire Steves from King's College London said: "In terms of the burden of Long COVID, it's good news that our research has found that having a double vaccination significantly reduces the risk of both catching the virus and if you do, developing long standing symptoms. However, among our frail, older adults and those living in deprived areas the risk is still significant and they should be urgently prioritised for second and booster vaccinations."
Professor Tim Spector from King’s College London and Lead investigator of ZOE COVID Study comments: “Vaccinations are massively reducing the chances of people getting Long COVID in two ways. Firstly, by reducing the risk of any symptoms by 8 to 10 fold and then by halving the chances of any infection turning into Long COVID, if it does happen. Whatever the duration of symptoms we are seeing that infections after two vaccinations are also much milder, so vaccines are really changing the disease and for the better. We are encouraging people to get their 2nd jab as soon as they can.” Health and Social Care Secretary, Sajid Javid said: "COVID-19 vaccines have saved more than 105,000 lives and prevented over 24 million infections in England alone. This research is encouraging, suggesting vaccines are not only preventing deaths but could also help prevent some of the longer lasting symptoms.
“We have invested £50 million in research to better understand the lasting effects of COVID and over 80 long COVID assessment services have opened across England as part of a £100 million expansion of care for those suffering the effects. “It is clear vaccines are building a wall of defence against the virus and are the best way to protect people from serious illness. I encourage everyone who is eligible to come forward for both their jabs as quickly as possible."