A Narrative Review of Pneumococcal Conjugate Vaccine Choices for Greater Access and Protection against Pneumococcal Diseases in the Philippines.

Background: Pneumococcal vaccination has been widely used for the prevention of pneumococcal disease, with two types of vaccines available since 2009. With the World Health Organization (WHO) recommendation of incorporating pneumococcal conjugate vaccines (PCVs) in National Immunization Programs (NIPs) worldwide, a ten-valent PCV (PHiD-CV) was initially introduced in the Philippines in 2012. This, however, transitioned to the use of the 13-valent PCV (Prevnar) subsequent to the recommendation of the Formulary Executive Council in 2014.

Objective: This review aimed to present evidence on pneumococcal disease and vaccine inclusion in the Philippine NIP from 2005 - 2021.

Methods: This narrative review compiled articles on Pneumococcus from January 2005 to October 2021, sourcing literature from databases such as BIOSIS Preview, CAB Direct, Embase, Google Scholar, and others.

Results: In the Philippines, there was a shift in prevalent serotypes of among children under five following the introduction of PCV13 in the National Immunization Program in 2014, with serotype 14 becoming the most common by 2018, and a significant reduction in isolates reported in 2020, where only serotypes 5, 19A, and 23F were identified among invasive strains. The immunogenicity results of a potential vaccine candidate should be factored into the overall evidence when conducting a reassessment of PCV.

Conclusion: As part of the decision making about the inclusion of the PCVs in the NIP of the Philippines, various factors such as local epidemiology, vaccine supply, cost, and programmatic characteristics must be careful weighed. Enhancing laboratory and surveillance capacity are essential to provide evidence-based decision-making in terms of existing serotype distribution and antimicrobial resistance (AMR) profile in the country. With the introduction of a new affordable formulation of a 10-valent PCV offering a comparable serotype coverage, the reassessment of choice of PCV with the consideration of all three formulations, namely PCV13, PHiD-CV, and SIIPL-PCV, may be warranted.