Cost-Effectiveness Analysis of the South African Infant National Immunization Program for the Prevention of Pneumococcal Disease

Abstract

Introduction Pneumococcal disease, which presents a substantial health and economic burden, is prevented through pneumococcal vaccination programs. We assessed the impact of switching from a 13-valent-based (PCV13) to lower 10-valent-based (PCV10-GlaxoSmithKline [GSK] or PCV10-Serum Institute of India [SII]) or higher-valent (PCV15 or PCV20) vaccination programs in South Africa. Methods A previously published decision-analytic model was adapted to a South African setting. Historical invasive pneumococcal disease (IPD) incidence data were used to project IPD incidence over time for each vaccination program on the basis of serotype coverage. Historical incidence (IPD, pneumonia, otitis media), mortality, costs, and utilities were obtained from the published literature. Cases of disease, direct medical costs (i.e., vaccination, IPD, pneumonia, and otitis media costs) (in 2022 South African rands), life-years, quality-adjusted life-years (QALY), and incremental cost per QALY were estimated over a 5- and 10-year horizon for PCV13 and the PCV10 vaccines. Additionally, a public health impact analysis was conducted comparing PCV13, PCV15, and PCV20. Results Continuing use of PCV13 would substantially reduce disease incidence over time compared with switching to either of the PCV10 lower-valent vaccines. Cases of IPD were reduced by 4.22% and 34.70% when PCV13 was compared to PCV10-GSK and PCV10-SII, respectively. PCV13 was also found to be cost saving over 5- and 10-year time horizons compared with PCV10-SII and to be cost-effective over a 5-year time horizon and cost-saving over a 10-year time horizon compared with PCV10-GSK. PCV20 was consistently estimated to prevent more cases than the PCV10 vaccines, PCV13, or PCV15. Conclusions Switching from a higher-valent to a lower-valent vaccine may lead to disease incidence re-emergence caused by previously covered serotypes. Maintaining PCV13 was estimated to improve public health further by averting additional pneumococcal disease cases and saving more lives and also to reduce total costs in most scenarios. Higher-valent PCVs can achieve the greatest public health impact in the pediatric vaccination program in South Africa. Supplementary Information The online version contains supplementary material available at 10.1007/s40121-023-00767-4.

Estimating the Clinical and Economic Impact of Switching from the 13-Valent Pneumococcal Conjugate Vaccine (PCV13) to Higher-Valent Options in Greek Infants

“…However, our results are aligned with two published studies, one from South Africa and another from the Netherlands, that estimated the public health impact of switching from a 10-valent or 13-valent PCV to higher-valent alternatives. In South Africa, switching from PCV13 to PCV20 in 2025 was estimated to avert more pneumococcal disease cases and deaths compared to all other vaccination strategies, which included switching from PCV13 to either two 10-valent alternatives or PCV15 [ 20 ]. In the Netherlands, which has a PCV10 NIP, switching to PCV13 followed by a subsequent switch to PCV20 was expected to generate the largest decrease in pneumococcal disease cases and deaths compared to maintaining PCV10 vaccination and then switching to PCV15, even when PCV20 is implemented one year later than PCV15 [ 19 ].…”

“…A previously published decision-analytic model was adapted for the Greek setting to compare the clinical and economic impact of switching from PCV13 to PCV15 in 2023 or to PCV20 in 2024 (after the expected licensure in infants) over a 10-year time horizon from a payer perspective [ 19 , 20 , 21 ]. The vaccine switching model uses historic age- and serotype-specific IPD incidence data to predict prospective pneumococcal disease trends based on the observed retrospective data across all ages and serotypes.…”

Pediatric Otitis Media in the New Pneumococcal Conjugate Vaccines Era: What’s Next?

“…8 The South African model showed even more prominent results, as S. pneumoniae was the causative for >30% of pediatric OM cases in historical cohorts. 9 In contrast, a Japanese study predicted milder reductions: 2.9% in pediatric OM cases if PCV15 would replace PCV13, given a 95% coverage rate of the new vaccine, and 2.7% given a 90% coverage rate. 10 To conclude, the expected general reduction in pediatric allcause OM burden over 10 years in several countries is estimated at 5-10% for PCV15 and at 10-15% if switched to PCV20, based on the country and the causative pneumococcal serotypes of OM.…”

“…8 The South African model showed even more prominent results, as S. pneumoniae was the causative for >30% of pediatric OM cases in historical cohorts. 9 In contrast, a Japanese study predicted milder reductions: 2.9% in pediatric OM cases if PCV15 would replace PCV13, given a 95% coverage rate of the new vaccine, and 2.7% given a 90% coverage rate. 10…”

Geographical migration and fitness dynamics of Streptococcus pneumoniae

“…Despite their success at reducing disease, their use has been linked to serotype replacement by NVTs in both invasive pneumococcal disease (IPD) and carriage 8 , 19 – 21 . In South Africa, this has been characterized by increases in NVT serotypes 8 and 15B among IPD, and increases in NVT serotypes 16F, 24, 35B and 11A among carriage isolates (8, 15B and 11A are now included in PCV20) 20 , 22 , 23 . Although there has been success in predicting the fitness of individual isolates based on the overall gene distribution in a population, quantitative measures of fitness linked to the serotype of individual isolates are lacking 24 , 25 .…”