Fully vaccinated people who later contract COVID-19 are significantly less likely to experience long COVID-19 compared to those who are unvaccinated, according to research published Sept. 1 in The Lancet Infectious Diseases.
More than 1.2 million adults in the U.K. who are part of the national COVID Symptom Study were involved in the research. Researchers evaluated participants who had received at least one dose of the Pfizer, Moderna or AstraZeneca mRNA vaccine between Dec. 8 and July 4, as well as a control group of unvaccinated individuals.
Of 971,504 people who were fully vaccinated, 0.2 percent developed a breakthrough infection.
Compared to those who were unvaccinated and had COVID-19, breakthrough cases were associated with a 49 percent lower risk of having lingering symptoms that lasted at least four weeks after infection, findings showed.
"This result suggests that the risk of long COVID is reduced in individuals who have received double [full] vaccination, when additionally considering the already documented reduced risk of infection overall," the study found.
The findings also added to a growing body of research that indicates breakthrough infections are less severe. For example, those in the breakthrough group were about twice as likely to be asymptomatic compared to unvaccinated people and had a 73 percent lower risk of hospitalization.
"We don’t have a treatment yet for long Covid," Claire Steves, PhD, lead study author and geriatrician at King's College London, told The New York Times, adding that vaccination "is a prevention strategy that everybody can engage in."
Scientists noted several study limitations, including that data was self-reported.
To view the full study manuscript, click here.