Influenza and pneumococcal vaccination and COVID-19 in kidney transplant patients

BACKGROUND: This study aims to investigate the effect of recent influenza and pneumococcal vaccines' administration on the development of COVID-19 infection in kidney transplant recipients during the pandemic. METHODS: The effect of influenza and pneumococcal vaccines on the clinical course of the disease in COVID-positive (COVID group, n: 105) and COVID-negative (control group, n: 127) recipients has been examined. The control group included patients with negative rRT-PCR test results. At the time of the study, no patient was vaccinated with COVID-19 vaccine. The patients' influenza and/or pneumococcal vaccination rates in 2019 and 2020 were determined. In 2019 and 2020, 32 and 33 people in the COVID-positive group and 61 and 54 people in the COVID-negative group had received influenza and/or pneumococcal vaccines, respectively. The median study follow-up times of the COVID-negative and COVID-positive groups were 13.04 and 8.31 months, respectively. RESULTS: Compared with the COVID-negative group, the patients in the COVID-positive group were younger and had a longer post-transplant time. In addition, the rate of transplantation from a living donor and the rate of COVID positivity in family members were also higher. The influenza vaccination rates in the COVID negative group were significantly higher than the COVID-positive group in 2020 (23.8% vs 37%, p = 0.031). Multivariate logistic regression analysis revealed that the presence of COVID-19 in family members and lack of pneumococcal vaccination in 2020 increased the risk of being positive for COVID-19. There was no significant difference in the hospitalization rates, the need for dialysis and intensive care, the hospital stay, and the graft dysfunction in the COVID-positive patients with and without influenza and pneumococcal vaccines. CONCLUSION: The observations made throughout this study suggest that influenza and pneumococcal vaccination in transplant patients may reduce the risk of COVID-19 disease and provide additional benefits during the pandemic period.