Research proposing the possibility of cross-immunity among different strains of coronaviruses has been carried out, suggesting that previous exposure to one of these viruses might provide a level of protective immunity against another. The goal of a recent retrospective cohort study was to understand whether patients who had previously been infected with the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) were less likely to contract COVID-19 and, consequently, experience less severe outcomes.
The study was conducted among patients screened for MERS-CoV at a tertiary hospital in Saudi Arabia between 2012 and the beginning of 2020. It included both patients who tested positive for MERS-CoV and those who tested negative. All these patients were followed up from early 2020 to September 2021 for the development of COVID-19, which was confirmed via RT-PCR testing. Out of the 397 patients overseen, 93 tested positive for MERS-CoV, with 65.6% being symptomatic. Of all the patients, 12.1% developed COVID-19 by the end of the follow-up period.
Notably, patients with positive MERS-CoV exhibited a marginally significant lower risk of contracting COVID-19 and being admitted to the hospital. Furthermore, the risk of developing COVID-19 declined further among patients who had been symptomatic during their MERS-CoV infection, with the difference now appearing statistically significant.
These observations could suggest that people previously infected with MERS-CoV might have partial cross-immunity, which makes them less likely to contract COVID-19 or be hospitalized due to the disease. However, further investigation using immunity markers may be beneficial to corroborate the findings.
Coronaviruses, which are single-stranded RNA viruses, predominantly cause respiratory infections. Like other viruses, coronaviruses trigger certain immune responses in the human body, providing some degree of protective immunity. The level of specific antibodies against SARS-CoV-2, another coronavirus, declines relatively quickly in most individuals, especially asymptomatic ones.
This study’s findings indicating the possibility of partial cross-immunity against COVID-19 among individuals previously infected with MERS-CoV may hold potential implications for tackling the ongoing pandemic. However, such conclusions merit further national examination for more comprehensive understanding.
Source: https://bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-023-08763-2