20-valent Pneumococcal Conjugate Vaccine (Suzhou VAC)

A nationwide surveillance program was conducted in Japan between April 2021 and March 2024 to assess the antimicrobial susceptibilities of Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis in pediatric patients aged <15 years with respiratory tract infections. A total of 1498 clinical isolates were collected from 18 medical institutions. Among 384 S. pneumoniae isolates, vaccine serotype coverage was 4.4 % for the 13-valent pneumococcal conjugate vaccine, 9.1 % for the 15-valent pneumococcal conjugate vaccine, and 30.2 % for the 20-valent pneumococcal conjugate vaccine. Serotype 35B was the most frequently isolated serotype. The proportion of S. pneumoniae isolates with penicillin G minimum inhibitory concentration ≥0.125 μg/mL increased compared with the 2017 survey, with serotypes 23A and 15A being the most common among less susceptible penicillin strains. Among 530 H. influenzae isolates, 9.2 % were β-lactamase-producing and 35.3 % were β-lactamase-non-producing ampicillin-resistant (BLNAR) strains, indicating a rise in BLNAR prevalence compared with the 2017 survey. Almost all of the H. influenzae isolates (98.3 % [521/530]) were non-encapsulated, and no capsular type b strain was detected. All 584 M. catarrhalis isolates were β-lactamase-producing strains, and one macrolide-resistant strain was identified for the first time in our surveillance program. These findings underscore the ongoing shifts in antimicrobial resistance and serotype distribution and provide information that will inform future treatment and prevention strategies.

Updated recommendations for adult pneumococcal vaccination in the U.S. (publication date: January 27, 2022) incorporated 2 new vaccines (15- and 20-valent pneumococcal conjugate vaccines), removed 13-valent pneumococcal conjugate vaccine, and called for pneumococcal conjugate vaccine use among immunocompetent adults aged 19-64 years with certain medical conditions. This study assessed uptake of recommendations and disparities in uptake across subgroups of adults.

A retrospective cohort design and data from Optum's deidentified Clinformatics Data Mart Database were employed. Study population comprised all adults aged ≥65 years and adults aged 19-64 years with ≥1 chronic (at-risk) or immunocompromising (high-risk) condition. Vaccine uptake (including 23-valent pneumococcal polysaccharide vaccine) was estimated using the Kaplan-Meier method.

During 21-month follow-up period, 13.2% of adults (n=6.8 million) received pneumococcal vaccine, mostly 20-valent pneumococcal conjugate vaccine (9.6%). By age/risk conditions, 20-valent pneumococcal conjugate vaccine uptake was highest among adults aged 65-66 years (23.8%) and at-risk/high-risk adults aged 60-64 years (12.1%) and lowest among at-risk/high-risk adults aged 19-49 years (4.7%). By immunization history, 20-valent pneumococcal conjugate vaccine uptake was highest among adults with a history of 23-valent pneumococcal polysaccharide vaccine uptake only (15.1%) or 13-valent pneumococcal conjugate vaccine uptake only (10.6%) and lowest among those without prior pneumococcal vaccination (8.7%) or with a history of 13-valent pneumococcal conjugate vaccine + 23-valent pneumococcal polysaccharide vaccine uptake (7.9%).

Fewer than ∼1 in 7 U.S. adults received 20-valent pneumococcal conjugate vaccine in the first 21 months after the updated recommendations. Uptake was lower among at-risk/high-risk adults aged <60 years, adults aged ≥75 years, and adults without prior pneumococcal vaccination. Routine evaluation of vaccination status by providers and additional strategies to increase uptake of recommend vaccines are warranted.