A new study that included more than a million adults in Britain has found that instances of people contracting the coronavirus after full vaccination are extremely rare — and that their risk of experiencing lingering symptoms of the disease in what’s known as “long COVID” is reduced by almost half.

The study, published in the Lancet Infectious Diseases journal on Wednesday, included nearly 1 million fully vaccinated British adults who reported receiving their first dose from December 2020 to July 2021. The study’s participants included people who received vaccines by Pfizer-BioNTech, Moderna or AstraZeneca — the latter of which is not approved for use in the United States.

The study adds to the evidence that vaccinations not only protect people against severe COVID-19 symptoms and reduce the risk of hospitalization, but also significantly reduce the likelihood of ongoing, debilitating symptoms after an infection — and drastically reduce the chances of getting infected at all. The study’s authors also suggest that immunocompromised people are the ones who should be prioritized for booster shots, rather than making the decision solely based on age.