JMIR Public Health Surveill. 2022 Oct 18. doi: 10.2196/38898. Online ahead of print.
ABSTRACT
BACKGROUND: Several risk factors have been identified for severe COVID-19 disease by the scientific community. In this work we focus on understanding the risks for severe COVID-19 infections post-vaccination, i.e. in breakthrough SARS-CoV-2 infections. Studying these risks by vaccine type, age, sex, comorbidities, any prior SARS-CoV-2 infection is important for making policy decisions regarding booster vaccinations for each vaccine.
OBJECTIVE: We perform a comparative study of the risks of hospitalization (n=1140) and mortality (n=159) in a SARS-CoV-2 positive cohort of 19,815 patients who were all fully vaccinated with either the Pfizer, Moderna or Janssen vaccines.
METHODS: We perform Cox regression analysis to calculate the risk factors for developing a severe breakthrough SARS-CoV-2 infection in the study cohort, by controlling for vaccine-type, age, sex, comorbidities and a prior SARS-CoV-2 infection.
RESULTS: We find lower hazard ratios for those receiving the Moderna vaccine (P<.001) and Pfizer vaccine (P<.001) with the lowest hazard rates being for Moderna, as compared to those who received the Janssen vaccine independent of age, sex, comorbidities, vaccine type and prior SARS-CoV-2 infection. Further, individuals who had a SARS-CoV-2 infection prior to vaccination had some increased protection over and above the protection already provided by the vaccines, from the risk of hospitalization (P=.001) and mortality (P=.035), independent of age, sex, comorbidities, and vaccine type. We find that the top statistically significant risk factors for severe breakthrough SARS-CoV-2 infections were age>50, male gender, moderate and severe renal failure, severe liver disease, leukemia, chronic lung disease, coagulopathy and alcohol abuse.
CONCLUSIONS: We find that among individuals who were fully vaccinated, the risk of severe breakthrough SARS-CoV-2 infection was lower for those who had received the Moderna or Pfizer vaccines, and higher for those who received the Janssen vaccine. This result from our analysis at a population level, suggests that individuals who received the Janssen vaccine could benefit from a booster shot. Our result on the influence of a previous SARS-CoV-2 infection necessitates further research into the impact of multiple exposures on the risk of developing severe COVID-19.
PMID:36265135 | DOI:10.2196/38898
