Recent Human Papillomavirus Vaccination is Associated with a Lower Risk of COVID-19: A US Database Cohort Study.

OBJECTIVE: To explore the association between human papillomavirus (HPV) vaccination and risk of coronavirus disease 2019 (COVID-19). Specifically, our study aimed to test the hypothesis that HPV vaccination may also induce trained immunity, which would potentially reduce the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and improve clinical outcomes. BACKGROUND: Several vaccines have been reported to trigger non-specific immune reactions that could offer protection from heterologous infections. A recent case report showed that verruca vulgaris regressed after COVID-19, suggesting a possible negative association between COVID-19 and HPV infection. METHODS: We enrolled 57,584 women with HPV vaccination and compared them with propensity score-matched controls who never received HPV vaccination in relation to the risk of COVID-19 incidence. Cox proportional hazard regression analysis was conducted to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Subgroup analyses stratified by age, race, comorbid asthma, and obesity were performed. RESULTS: The risk of COVID-19 incidence was significantly lower in those who had recently received the HPV vaccine (within 1 year after HPV vaccination, aHR: 0.818, 95% CI 0.764-0.876; within 1-2 years after HPV vaccination, aHR: 0.890, 95% CI 0.824-0.961). Several limitations were recognized in this study, including residual confounding, problems of misclassification due to the use of electronic health record data, and that we were unable to keep track of the patients' HPV infection status and the HPV antibody levels in those who had received the vaccine. CONCLUSIONS: Recent HPV vaccination was associated with a lower risk of incident COVID-19 and hospitalization. Based on the promising protective effect of HPV vaccine shown in this study, these findings should be replicated in an independent dataset. Further studies are needed to provide a better understanding of the underlying mechanisms and the differences in risks among 2-, 4-, or 9-valent HPV vaccine recipients.

Risk of autoimmune diseases in patients with COVID-19: A retrospective cohort study.

Background: There are a growing number of case reports of various autoimmune diseases occurring after COVID-19, yet there is no large-scale population-based evidence to support this potential association. This study provides a closer insight into the association between COVID-19 and autoimmune diseases and reveals discrepancies across sex, age, and race of participants. Methods: This is a retrospective cohort study based on the TriNetX U.S. Collaborative Network. In the test-negative design, cases were participants with positive polymerase chain reaction (PCR) test results for SARS-CoV-2, while controls were participants who tested negative and were not diagnosed with COVID-19 throughout the follow-up period. Patients with COVID-19 and controls were propensity score-matched (1: 1) for age, sex, race, adverse socioeconomic status, lifestyle-related variables, and comorbidities. The primary endpoint is the incidence of newly recorded autoimmune diseases. Adjusted hazard ratios (aHRs) and 95% confident intervals (CIs) of autoimmune diseases were calculated between propensity score-matched groups with the use of Cox proportional-hazards regression models. Findings: Between January 1st, 2020 and December 31st, 2021, 3,814,479 participants were included in the study (888,463 cases and 2,926,016 controls). After matching, the COVID-19 cohort exhibited significantly higher risks of rheumatoid arthritis (aHR:2.98, 95% CI:2.78-3.20), ankylosing spondylitis (aHR:3.21, 95% CI:2.50-4.13), systemic lupus erythematosus (aHR:2.99, 95% CI:2.68-3.34), dermatopolymyositis (aHR:1.96, 95% CI:1.47-2.61), systemic sclerosis (aHR:2.58, 95% CI:2.02-3.28), Sjögren's syndrome (aHR:2.62, 95% CI:2.29-3.00), mixed connective tissue disease (aHR:3.14, 95% CI:2.26-4.36), Behçet's disease (aHR:2.32, 95% CI:1.38-3.89), polymyalgia rheumatica (aHR:2.90, 95% CI:2.36-3.57), vasculitis (aHR:1.96, 95% CI:1.74-2.20), psoriasis (aHR:2.91, 95% CI:2.67-3.17), inflammatory bowel disease (aHR:1.78, 95%CI:1.72-1.84), celiac disease (aHR:2.68, 95% CI:2.51-2.85), type 1 diabetes mellitus (aHR:2.68, 95%CI:2.51-2.85) and mortality (aHR:1.20, 95% CI:1.16-1.24). Interpretation: COVID-19 is associated with a different degree of risk for various autoimmune diseases. Given the large sample size and relatively modest effects these findings should be replicated in an independent dataset. Further research is needed to better understand the underlying mechanisms. Funding: Kaohsiung Veterans General Hospital (KSVGH111-113).