Vaccination Coverage among Institutionalized Elderly Population: A Case Study in Cascais, Portugal

Abstract Vaccination stands as a cornerstone of public health, significantly reducing the morbidity and mortality associated with infectious diseases. However, the aging demographic, with declining homeostasis and immunosenescence, presents new challenges. Those residing in nursing homes face heightened risks of infectious diseases due to proximity and interactions with multiple staff members. In Portugal, elderly vaccination against tetanus/diphtheria (Td) is integrated into the National Vaccination Program, with additional official recommendations for pneumococcal (Pn), seasonal influenza, and COVID-19 vaccinations. Specific vaccination campaigns in nursing homes for influenza and COVID-19 are coordinated by Public Health Units. This study aimed to assess the vaccination coverage for these vaccines among the institutionalized elderly in Cascais municipality and evaluate the implementation of official recommendations. A survey of nursing homes in Cascais was conducted, and the vaccination status of residents was assessed through electronic records in February 2024. Statistical analysis was performed. Vaccination status for each vaccine was considered valid if individuals had received at least one dose of Pn13 or Pn23, a Td vaccine dose within the last 10 years, and vaccinations against influenza and COVID-19 within the last 6 months. Among 2189 institutionalized elderly in Cascais, 87% were vaccinated against both influenza and COVID-19, 39% against Td, and 17% against pneumococcal disease. While influenza and COVID-19 vaccination coverage is high, the tetanus/diphtheria vaccination rate is low, and pneumococcal vaccination is very low, despite official recommendations. This population remains at increased risk for preventable diseases. Monitoring vaccination status and implementing targeted vaccination campaigns are crucial for increasing coverage, realizing health and economic benefits and preventing severe diseases. Key messages • Vaccination is essential for safeguarding the health of institutionalized elderly populations. There is a need for targeted interventions to address preventable diseases and protect these individuals. • Monitoring vaccination status and implementing targeted campaigns are critical for increasing coverage and realizing health and economic benefits among elderly populations in nursing homes.