BackgroundThe effects of COVID‐19 vaccines on immunocompromised people such as hemodialysis (HD) patients are an important topic that should be addressed. This study reports an observation of the effect of the third dose of the Sinopharm vaccine (SphV3) on the level of hepatitis B surface antibody (anti‐HBs) in HD patients, and the differences between anti‐HBs titers before and after SphV3 were analytically evaluated.MethodsThis single‐center observational study involved all HD patients presented to Shariati Hospital, Tehran, Iran, from February 2021 to March 2022. All patients received three doses of the Sinopharm vaccine over 8 months. The anti‐HBs level is measured every 6 months as the routine evaluation against HBV infection for all HD patients. Three months before (anti‐HBs‐B3) and 3 months after (anti‐HBs‐A3) SphV3 were the routine times to measure the anti‐HBs titer during this study.ResultsTwenty‐five HD patients were enrolled. Overall, the anti‐HBs‐A3 was significantly higher than anti‐HBs‐B3 (p = 0.001). The anti‐HBs levels before and after SphV3 were not statistically remarkable in patients with diabetes and ischemic heart disease. The patients with a history of kidney transplant and those with a history of COVID‐19 had significant differences between anti‐HBs‐B3 and anti‐HBs‐A3 (p = 0.002, p = 0.003, respectively).ConclusionOur findings revealed that inactivated COVID‐19 vaccine may be involved in the humoral immune response to hepatitis B in HD patients. It may be novel and have significant implications for the vaccination protocol for immunocompromised patients, including those undergoing HD and transplant recipients.