Do Pneumococcal Conjugate Vaccines Represent Good Value for Money in a Lower-Middle Income Country? A Cost-Utility Analysis in the Philippines
PURPOSE OF REVIEW This review provides the otolaryngologist with the evolving understanding of various aspects of pneumococcal conjugate vaccines (PCVs) that are related to their effect on the respiratory tract RECENT FINDINGS The efficacy of PCVs against invasive pneumococcal disease and pneumonia is well established and is documented in several well-conducted studies. However, the effect of PCVs on otitis media is less obvious and more complex. PCVs clearly reduce diseases caused by vaccine-type (VT) pneumococci, but replacement of VT serotypes by non-VT serotypes in nasopharyngeal carriage of Streptococcus pneumoniae is responsible for the increase in acute otitis media (AOM) caused by non-VT serotypes. Furthermore, an increased rate of AOM caused by Haemophilus influenzae and Moraxella catarrhalis was found. Since most antibiotic-resistance in S. pneumoniae is confined to VT serotypes, vaccine use also reduces antibiotic resistance. The reduction of carriage by PCVs is responsible for the reduction of spread of VT pneumococci (herd immunity). Thus a modification of AOM rather than just a simple reduction is seen with the widespread use of PCV. SUMMARY Acute otitis media in the era of widespread use of PCV is modified. A disease with reduced VT serotypes, reduced antibiotic resistance, and a lower rate of sequelae is to be expected. However, replacement with potential virulent organisms and development of antibiotic resistance in non-VT pneumococci is a possibility that needs careful monitoring.