Long COVID is less likely to affect vaccinated people than unvaccinated people, a new review of 15 studies by the UK Health Security Agency released on Tuesday has concluded.

UKHSA said the people who received two doses of Pfizer-BioNTech , AstraZeneca or Moderna vaccine, or one dose of the single-shot J&J vaccine, were around half as likely to develop symptoms of long COVID compared to the unvaccinated.

"These studies add to the potential benefits of receiving a full course of the COVID-19 vaccination," said Dr Mary Ramsay, head of immunization at UKHSA.

"Vaccination is the best way to protect yourself from serious symptoms when you get infected and may also help to reduce the longer-term impact."

British Prime Minister Boris Johnson has lifted COVID-19 restrictions in England as booster shots and the lower severity of the omicron variant weaken the link between cases and death.

However, Britain is still averaging around 50,000 cases each day, and mild cases of COVID-19 can still lead to debilitating long COVID and associated symptoms of fatigue, memory issues and brain fog.

The UKHSA said that an estimated 2% of the UK population had reported symptoms of long COVID, with the most common symptoms being fatigue, shortness of breath and muscle or joint pain.

Of four studies that compared long COVID symptoms before and after vaccination, three suggested that more people reported an improvement in long COVID symptoms rather than a worsening following vaccination.

Three more studies found that long COVID symptoms improved in those who got vaccinated, compared to those who remained unvaccinated.