Cleveland Clinic Statement on Previous COVID-19 Infection Research

Updated August 16, 2021

Media Contact

Andrea Pacetti 216.316.3040

Cleveland Clinic recommends those who are eligible receive the COVID-19 vaccine.   

In June, we shared research that provided insight into how the immune system protects the body after a confirmed COVID-19 infection. The study followed Cleveland Clinic caregivers over five months as the vaccination process was beginning. The data showed that the vaccine was extremely effective in preventing COVID-19 infection. In addition, during the study, none of the employees who had confirmed positive PCR tests and remained unvaccinated were re-infected.  It’s important to note that this study was conducted in late 2020 and early 2021, before the emergence of the Delta variant.   

More research is needed. We do not know how long the immune system will protect itself against re-infection after COVID-19, as our study only looked at individuals over a five-month period, or how well-protected previously infected individuals are against variants. It is also important to keep in mind that this study was conducted in a population that was younger and healthier than the general population.  

It is safe to receive the COVID-19 vaccine even if you have previously tested positive, and we recommend all those who are eligible receive it.  

About Cleveland Clinic
Cleveland Clinic – now in its centennial year – is a nonprofit multispecialty academic medical center that integrates clinical and hospital care with research and education. Located in Cleveland, Ohio, it was founded in 1921 by four renowned physicians with a vision of providing outstanding patient care based upon the principles of cooperation, compassion and innovation. Cleveland Clinic has pioneered many medical breakthroughs, including coronary artery bypass surgery and the first face transplant in the United States. U.S. News & World Report consistently names Cleveland Clinic as one of the nation’s best hospitals in its annual “America’s Best Hospitals” survey. Among Cleveland Clinic’s 70,800 employees worldwide are more than 4,660 salaried physicians and researchers, and 18,500 registered nurses and advanced practice providers, representing 140 medical specialties and subspecialties. Cleveland Clinic is a 6,500-bed health system that includes a 173-acre main campus near downtown Cleveland, 19 hospitals, more than 220 outpatient facilities, and locations in southeast Florida; Las Vegas, Nevada; Toronto, Canada; Abu Dhabi, UAE; and London, England. In 2020, there were 8.7 million total outpatient visits, 273,000 hospital admissions and observations, and 217,000 surgical cases throughout Cleveland Clinic’s health system. Patients came for treatment from every state and 185 countries. Visit us at clevelandclinic.org. Follow us at twitter.com/ClevelandClinic. News and resources available at newsroom.clevelandclinic.org.

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