Merck: Pneumococcal Vaccination, a US Dynamic Transmission Model

Merck & Co., Rahway, NJ, developed a dynamic transmission model to assess the impact of pneumococcal vaccination strategies in the United States. The model simulates the spread of Streptococcus pneumoniae by considering different age groups and specific serotypes, incorporating factors like vaccine coverage, effectiveness, and serotype competition. By calibrating the model with historical data, they projected the epidemiological benefits of using the newer PCV15 (a 15-valent pneumococcal vaccine) compared to the currently used PCV13 (13-valent), suggesting that PCV15 could lead to a further reduction in pneumococcal diseases. The study highlights the model's potential for evaluating various vaccination policies and understanding the complex dynamics of pneumococcal transmission.

·      PCV15 is projected to reduce invasive pneumococcal disease incidence by 6.04% over 10 years compared to PCV13.

·      PCV15 is estimated to prevent around 13.54 more invasive pneumococcal disease cases in children under 2 and 4.82% more cases in adults over 65 than PCV13.

·      PCV15 is estimated to reduce non-bacteremic pneumococcal pneumonia cases by 5.5% and acute otitis media cases (an inflammatory disease of the middle ear) by 3% compared to PCV13.

The model is flexible, accurate, and can be adapted to other country settings with different pneumococcal epidemiology and vaccination policies. It could also be further improved by incorporating the impact of other viral pathogens that may facilitate invasive pneumococcal disease.

Malik TM, Bakker KM, Oidtman RJ, Sharomi O, Meleleo G, Nachbar RB, Elbasha EH. A dynamic transmission model for assessing the impact of pneumococcal vaccination in the United States. PLoS One. 2025 Apr 2;20(4):e0305892. doi: 10.1371/journal.pone.0305892. PMID: 40173185.

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0305892