OBJECTIVES: This study aimed to evaluate the potential public health impact and cost-effectiveness of switching from PCV13 to PCV15 in the national immunization program (NIP) for infants in Saudi Arabia in a 3+1 schedule.

METHODS: State-transition Markov model was adapted to a Saudi Arabian healthcare setting to simulate the incidence, costs and mortality of non-bacteremic pneumococcal pneumonia, invasive pneumococcal disease, acute otitis media and post-meningitis sequelae over life time horizon. The model was designed to follow the entire population tracking individuals aged 0 to 77 years old with a one-year cycle length. During each cycle, another cohort of newborns entered the model. Herd immunity was considered. Epidemiological, economic and sociodemographic inputs were obtained from published local and regional data and online databases. The vaccine acquisition costs were obtained from Saudi Food and Drug Authority.

RESULTS: Switching from PCV13 to PCV15 in Saudi Arabian NIP is projected to prevent additional 5,860 IPD cases, 41,278 NBPP cases, 1,132,450 AOM cases and 56 PMS cases over life-time horizon. Furthermore, PCV15 would prevent 1,493 IPD deaths and 351 pneumonia deaths compared to PCV13, leading to gains of 7,923 life-years and 9,451 quality-adjusted life years (QALY) over the 77-year time horizon. Switching from PCV13 to PCV15 is highly cost-effective with incremental cost-effectiveness ratio (ICER) equaling 48,444 SAR per QALY from societal perspective and 78,498 SAR per QALY from payer perspective, being significantly lower than willingness-to-pay threshold in Saudi Arabia (114,193 SAR per QALY). Comprehensive sensitivity analysis demonstrated the robustness of these results. Incremental costs for immunization with PCV15 for 77 years will be 0.35% (457,838,886 SAR) higher compared with PCV13 from societal perspective.

CONCLUSIONS: Including PCV15 in Saudi Arabian NIP can prevent a significant number of pneumococcal cases and deaths. PCV15 further offers value as a highly cost-effective immunization strategy compared to PCV13 both from payer and societal perspectives.