[Safety evaluation of simultaneous administration of quadrivalent influenza split virion vaccine and 23-valent pneumococcal polysaccharide vaccine in adults aged 60 years and older].

To evaluate the safety of simultaneous administration of quadrivalent influenza split virion vaccine and 23-valent pneumococcal polysaccharide vaccine in adults aged 60 years and older. From November 2021 to May 2022, eligible participants aged 60 years and older were recruited in Taizhou City, Jiangsu Province, China, and a total of 2 461 participants were ultimately enrolled in this study. Each participant simultaneously received one dose of quadrivalent influenza split virion vaccine and one dose of 23-valent pneumococcal polysaccharide vaccine. The safety was observed within 28 days after vaccination. Safety information was collected through voluntary reporting and regular follow-ups. All 2 461 participants completed the simultaneous administration of both vaccines and the safety follow-ups for 28 days after vaccination. The mean age of the participants was (70.66±6.18) years, with 54.61% (1 344) being male, and all participants were Han Chinese residents. About 22.51% (554) of the participants had underlying medical conditions. The overall incidence of adverse reactions within 0-28 days after simultaneous vaccination was 2.07% (51/2 461), mainly consisting of Grade 1 adverse reactions [1.83% (45/2 461)], with no reports of Grade 4 or higher adverse reactions or vaccine-related serious adverse events. The incidence of local adverse reactions was 0.98% (24/2 461), primarily presenting as pain at the injection site [0.93% (23/2 461)]. The incidence of systemic adverse reactions was 1.42% (35/2 461), with fever [0.85% (21/2 461)] being the main symptom. In the group with underlying medical conditions and the healthy group, their overall incidence of adverse reactions was 2.53% (14/554) and 1.94% (37/1 907), respectively. The incidence of local adverse reactions in the two groups was 1.62% (9/554) and 0.79% (15/1 907), respectively, and the incidence of systemic adverse reactions was 1.44% (8/554) and 1.42% (27/1 907), respectively, with no statistically significant differences between them (all >0.05). It is safe for adults aged 60 years and older to receive quadrivalent influenza split virion vaccine and 23-valent pneumococcal polysaccharide vaccine at the same time.