A new study that was recently published on the preprint server medRxiv examined the effectiveness of the bivalent coronavirus (COVID-19) vaccine in the real world. The study was conducted by researchers from the Cleveland Clinic Health System (CCHS) and involved 51,011 CCHS employees. Of those, 10,804 received the bivalent vaccine, with 9,595 receiving the Pfizer vaccine and 1,178 receiving the Moderna vaccine. The results showed that the bivalent vaccine provided an efficacy of about 30%. In addition, those who had been exposed to SARS-CoV-2 in the past six to nine months were twice as likely to be re-infected, and those with exposure in the past nine to 12 months were at a 3.5-fold greater risk of contracting COVID-19 than those infected within the last 90 days.
It is important to note that the study was limited in its scope, and that no children or immunocompromised individuals were included. Therefore, the results of the study should not be taken as definitive or used to guide clinical practice or health-related behavior. The study provides evidence that the bivalent COVID-19 vaccine can provide some protection against SARS-CoV-2 infection, but further research is needed to understand the impact of multiple COVID-19 vaccines on the future risk of infection.