Most common long-term symptoms reduced by 50-80% in vaccinated individuals who were infected
A new study shows a major reduction in the most commonly-reported long-term symptoms of COVID-19 among individuals vaccinated with two doses and infected with the virus compared to non-vaccinated previously-infected individuals.
Those vaccinated and infected individuals reported no more of these symptoms than individuals who were never infected with the virus.
These findings suggest that two doses of COVID-19 vaccine protect against long COVID. These results were not observed in individuals who received just a single dose.
The research was led by Prof. Michael Edelstein, of Bar-Ilan University's Azrieli Faculty of Medicine in Safed, in collaboration with three of the Faculty's affiliated hospitals: Ziv Medical Center, Baruch Padeh Medical Center, and the Galilee Medical Center. The findings were reported on the medRxiv pre-print server.
The study, involving over 3,000 participants, showed a 50-80% reduction in seven of the ten most commonly reported long-term symptoms, such as fatigue, headache, weakness and muscle pain, four to 11 months after infection among vaccinated cases compared with unvaccinated ones. These vaccinated cases were no more likely to report these symptoms than people who reported never having been diagnosed with COVID-19.
"A double comparison of vaccinated vs. unvaccinated COVID-19 cases followed by comparing vaccinated COVID-19 cases to people reporting no infection enabled us to show not only that vaccinated people were experiencing much fewer long COVID symptoms than unvaccinated people, but that that they did not report any more symptoms than people never infected," says Prof. Edelstein, whose PhD student Paul Otiku led the complex data analysis.
This study is the first of comprehensive research on a large cohort of patients -- both infected and non-infected with COVID-19 – whose health Edelstein and colleagues will continue to analyze over the coming years to understand the long-term impact of COVID-19. The cohort is comprised of over 4,000 participants, and more are being recruited.
The finding that vaccination is likely to protect against long COVID may encourage countries to expand their vaccination drives, and persuade individuals not yet vaccinated to exercise their right to get vaccinated.