Adults who are elderly or who have underlying health conditions are at particular risk of Streptococcus pneumoniae infections, and pneumococcal vaccines are available. Nonetheless, only national recommendations from countries of North America and Europe have been previously reviewed in the literature. Consequently, we aimed to collate national guidelines for adult pneumococcal immunization across the 161 countries within the World Health Organization (WHO) regions-the Americas (except Canada and the United States of America), Africa, Eastern Mediterranean, South East Asia, and Western Pacific-from country-level official websites and documents, from the WHO portal, and from direct contact with public health officials, pertinent governmental sources, or local vaccination experts. For 40.4 % (65/161) of these countries, adult pneumococcal vaccination information was available. Among these 65 with available information, 63.1 % (41/65) include adult pneumococcal vaccination in the national vaccination schedule: 58.5 % (24/41) recommend vaccination both for older adults and for risk groups, while 9.8 % (4/41) recommend it only for older adults, and 31.7 % (13/41) only for risk groups. Of note, among the 13 national risk based-only recommendations, 30.8 % (4/13) are age-dependent and strictly reserved for older adults. The regions where age-based adult pneumococcal vaccination recommendations seem to predominate are South East Asia, Western Pacific, and the Americas. The threshold for age-based pneumococcal vaccination recommendations varies between 50 and 70 years of age. The Americas has the highest proportion of countries with risk-based recommendations. Three-quarters of these countries include PCV and PPV23 in the recommendations, most often given in sequence. Less than half of countries of the five WHO regions analyzed have accessible information on adult pneumococcal vaccination, and only 25.5 % (41/161) of all countries reviewed recommend adult pneumococcal immunization within the national vaccination schedule. Policymakers should consider extending pneumococcal vaccination guidelines-adapted to national priorities for adult healthcare-as based on local age demographics and risk factor predominance.

Background: Pneumococcal disease (PD) is a major cause of morbidity and mortality in young children in Asia and globally. Pneumococcal conjugate vaccines (PCVs) have significantly reduced the burden of PD when included in pediatric national immunization programs (NIPs). This study estimates the clinical and economic burden of PD due to serotypes contained in different PCVs in children aged < 5 years in eight Asian countries/territories. Methods: Based on published data, a cohort-based decision analytic model was used to estimate annual PD cases, deaths, and direct medical costs associated with serotypes contained in PCV10, PCV13, PCV15, and PCV20. Results: PD incidence rates were lower in regions with PCV13 in their NIP than those without. Serotypes contained in higher but not lower valency PCVs resulted in a significant incremental clinical and economic burden, although the difference between PCV13 and PCV15 serotypes was generally small. Moving from PCV13 to PCV20 was estimated to result in greater clinical and economic burden reductions. Conclusions: This study demonstrates the remaining and incremental burden of PD from PCV10 to PCV20 serotypes in young children in selected Asian regions. Extending NIP access to higher-valency PCVs with broader serotype coverage and improving vaccine uptake will help prevent morbidity and deaths and save healthcare costs.

Background: Clinical trials and serological studies have demonstrated that vaccine-induced antibodies can cross-react with some non-vaccine serotypes. However, there are limited longitudinal data on the impact of pneumococcal conjugate vaccines (PCV) on cross-reactive serotypes after implementation in immunization programs. This study examines the impact of PCVs on pneumococcal disease cases due to potential cross-reactive serotypes. Methods: Eleven countries with serotyped invasive pneumococcal disease (IPD) surveillance data that had introduced PCV10 or PCV13 were identified. The analysis focused on IPD cases due to serotypes included in PCV10 and PCV13 (PCV10/13 VTs: 6B, 9V, 19F, 23F; PCV13 only VTs: 6A, 19A) and to vaccine-related serotypes (VRTs: 6C, 9N, 23A, 23B) that may be immunologically related to VTs in children under 5 years old. For each country, the number of IPD cases were charted over time according to serogroup. Results: Following PCV introduction, reductions in VT IPD cases were observed in all countries, while some VRT IPD cases remained unchanged or increased. Serotype 19A cases declined in PCV13 countries but increased in countries that introduced PCV10. VRT 6C cases rose in PCV10 countries but showed minimal change in PCV13 countries. In PCV13 countries, 9N cases remained unchanged while 23A and 23B experienced modest increases. Conclusions: The inclusion of VT 19A in PCV13, but not in PCV10, may account for the significant increase in VRT 19A cases in PCV10 countries. The slight change in VRT 6C cases in PCV13 countries compared to the significant rise in PCV10 countries suggests that PCV13 provides cross-protection for serotype 6C through serotype 6A. Cross-protection could not be determined for other VRTs, as their cases increased or remained unchanged or had insufficient data for evaluation.

Pneumococcal diseases have a major impact on childhood morbidity and mortality across the world. While any child could be infected, those with certain health conditions have an increased risk of infection and subsequent disease severity. This report provides an overview of pneumococcal vaccination policies focused on children considered to be at particular risk of pneumococcal disease. Risk-group targeted vaccination schedules were retrieved from the World Health Organization and the European Centre for Disease Prevention and Control portals, and from countries' official governmental and/or public health websites. Additional information was gathered directly from governmental sources and specialists working in the field. Of the 195 countries considered, 37.9% (74/195) provide information on vaccination policies for children with risk factors, with 85.1% of these (63/74) recommending a differentiated pneumococcal vaccination schedule. Among countries with recommendations, 65.1% (41/63) suggest administration of one or more pneumococcal conjugate vaccine (PCV) boosters after the general infant vaccination schedule, followed by the administration of the 23-valent polysaccharide vaccine (PPV23). In contrast, 12.7% of countries (8/63) recommend only subsequent PPV23, whereas 20.6% (13/63) recommend the administration of only PCV revaccination. PCV13 is the most frequently recommended PCV, while the higher-valency PCV15 and PCV20 are already recommended by five countries. Overall, risk-targeted recommendations vary widely according to the vaccination schedule employed, the risk conditions considered, and the level of detail of the recommendations. Pneumococcal vaccination schedules specifically tailored for children with risk factors are relatively exceptional - present in about one-third of countries - in contrast to the more widely adopted routine infant vaccination schedules. When available, these risk-group recommendations vary widely by conditions and dosing. Continued guidelines development and vaccine access are needed to support the provision of pneumococcal vaccination to children with risk factors.