The pathogen responsible for COVID-19, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a respiratory virus that primarily targets pulmonary epithelial cells. The virus also affects the digestive system, heart, liver, kidney, and brain in addition to the respiratory tract.
After their clinical recovery, many SARS-CoV-2-infected individuals continue to have long-lasting symptoms for weeks or months. This condition is known as long-COVID or post-COVID conditions. The most prevalent long-term effects include cardiovascular, pulmonary, and mental disorders. According to estimates, long-COVID affects more than 200 million people worldwide.
Researchers investigated the effectiveness of COVID-19 vaccinations against long-COVID symptoms in this systematic review and meta-analysis.
Clinical trials and real-world studies conducted during the pandemic have indicated that most COVID-19 vaccines are highly effective against wild-type SARS-CoV-2 infection, severe COVID-19, hospitalization, and mortality.
In order to find studies that examined the effectiveness of the COVID-19 vaccine against long-COVID in individuals who had received at least one dose of mRNA-based (Pfizer and Moderna) or adenoviral vector-based (AstraZeneca and Janssen) vaccines, the researchers searched various scientific study-reporting databases. The restricted search window ran from December 2019 to April 2022.
A total of 26 studies were initially screened, of which ten were included in the systematic review. All studies were non-randomized, including five prospective cohort studies, four retrospective cohort studies, and one case-control study. Of the ten reviewed studies, six were included in the quantitative meta-analysis. The effectiveness of Pfizer, Moderna, Janssen, and AstraZeneca vaccines was evaluated in 9, 7, 6, and 5 studies, respectively.
