Introduction There are scarce data on the safety of the COVID-19 vaccines in Gynecologic cancer patients. This study evaluated the safety of COVID-19 vaccines among gynecologic cancer patients.

Methods A descriptive study was performed on gynecologic cancer patients who received at least one COVID-19 vaccine at King Chulalongkorn Memorial Hospital, Thailand, from January 2020 to August 2021. The evaluation was conducted via telephone interviews. Logistic regression was conducted to assess the association between demographics, clinical factors, cancer treatment status, and the occurrence of any grade adverse event. The number of COVID-19 infections of patients receiving at least two vaccine doses was studied.

Results Of 294 patients interviewed, the most common adverse effects were the grade 1–2 injection site reaction. One patient developed grade 3 fever and seizure ten days after the first dose of the AstraZeneca vaccine. Between the 2nd to 4th dose of the vaccination, most of the adverse events were the grade 1–2 injection site reaction. No severe allergic reactions or grade 4 adverse events were reported. The study found that patients under 60 had more adverse events than older patients (Adjusted odds ratio 1.99 [95% CI 1.08–3.71]; p=0.029). The treatment status did not affect the adverse events. Of 283 who received two doses, 27.6% were infected with COVID-19.

Conclusion/Implications COVID-19 vaccines are safe among gynecological cancer patients, both those receiving active anticancer therapy and those in surveillance. The younger patients frequently reported more adverse effects.