A systematic review of 511 studies confirmed that vaccines against COVID-19, RSV, and influenza are safe and effective for the 2025–2026 season as well. In children aged 5–17 years, the BNT162b2 COVID-19 vaccine was 65% effective in preventing hospitalization or emergency room visits against the XBB.1.5 subvariant. In adults, the efficacy of vaccines against hospitalization was 46–58% for the XBB.1.5 subvariant, 14–54% for the dominant JN.1 subvariant, and 68% for KP.2. In immunocompromised adults, the efficacy against hospitalization was 37%. The RSV vaccine was associated with 18.2 cases of Guillain-Barré syndrome per million doses in older adults. Concomitant administration of vaccines against COVID-19, RSV and influenza, even with other vaccines, has an acceptable immunological and safety profile. The study confirms that vaccination provides strong protection against hospitalization in all monitored groups.