A new study involving millions of people in the UK found that people who are fully vaccinated against COVID-19 are less likely to develop long COVID. In fact, having both shots cut their chances of developing long COVID symptoms by about 50% compared to those who haven’t been vaccinated at all.
The study, published in The Lancet Infectious Diseases this week, includes data for more than a million people in the U.K. who reported receiving at least one dose of a COVID-19 vaccine, through an app. (The COVID Symptom Study app was designed by health tech company Zoe and a collection of research institutions, including King’s College London.)
Of the 1.24 million people on the app who reported receiving one dose of a COVID-19 vaccine, 6,030 people (0.5%) developed a coronavirus infection. And of 971,500 people who reported getting a second dose, 2,370 people (0.2%) reported having COVID-19 at least seven days after their second shot. Those participants were matched with similar control participants, who were unvaccinated people who used the app for at least two weeks and tested positive for COVID-19.
Their results showed that, compared to unvaccinated people who developed COVID-19, those who were fully vaccinated and developed breakthrough infections were less likely to be hospitalised with COVID-19, less likely to experience five or more Coronavirus symptoms, and were less likely to still have symptoms 28 days later (long COVID).
“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,” the researchers wrote. “This result 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.”
This and other studies confirm that breakthrough infections among fully vaccinated people are generally rare. And this research suggests that, even if someone does develop one of those infections, they’ll likely have fewer symptoms and less severe symptoms than those who are unvaccinated. This study also shows that for those who develop a breakthrough infection, being vaccinated helps protect them from also experiencing lingering COVID symptoms.
People who have those prolonged COVID-19 symptoms, sometimes called “long haulers,” might experience a wide variety of issues such as difficulty with sleep or memory in addition to those they felt during the acute phase of the infection, like fatigue and loss of smell or taste. And previous research found that long-lasting COVID symptoms are relatively common after even mild infections. Experts are still working to understand how common long COVID is and why some people develop the condition while others don’t.
These results offer an important reminder that the best way to protect yourself from COVID-19 and all of its possible health consequences is to get vaccinated.