Follow the latest coronavirus updates
Fully vaccinated adults are 47 per cent less likely to suffer from long Covid after contracting the virus, a study published in The Lancet has suggested.
Using the Zoe Covid Symptom Study app, data from more than 2 million people was logged by a team at King's College London between December 8, 2020, and July 4, 2021.
"We found that the odds of having symptoms for 28 days or more after post-vaccination infection were approximately halved by having two vaccine doses," researchers wrote in the study.
"This suggests that the risk of long Covid is reduced in individuals who have received double vaccination, when additionally considering the already documented reduced risk of infection overall."
Study lead Prof Tim Spector from King's College outlined the ways in which vaccines were "massively reducing" the chances of people getting long Covid.
Prof Spector said they reduced the risk of any symptoms by eight-to-tenfold.
"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," he said.
"We are encouraging people to get their second jab as soon as they can."
The study looked at the two main vaccines being used in the UK, the ones produced by Pfizer and AstraZeneca.
But they did not have enough evidence to look at Moderna, which was approved for use in 12 to 17-year-olds in Britain last month.
Both vaccines showed a similar reduction in risk when examined independently.
Frail and deprived population still at risk
Researchers found that double-vaccinated people who get the virus were 73 per cent less likely to be admitted to hospital, and 31 per cent less likely to have acute symptoms.
The symptoms that did break through in fully vaccinated people were similar to those of unvaccinated adults, but much less severe. The most common were loss of smell, cough, fever, headaches and fatigue.
Lead researcher Dr Claire Steves, also from King's College, acknowledged the good news but had a warning for the frail and deprived.
"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," she said.