Comparative Effectiveness of the 7-Valent Pneumococcal Conjugate Vaccine and Haemophilus Influenzae Type b Vaccine for the Prevention Acute Otitis Media with Tympanic Membrane Perforation: A Secondary Analysis of Data from a Randomized Trial among Bangladeshi Infants
Creators: name: Warner, Dane
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2015

description: Background: Streptococcus pneumoniae is the most common bacterial cause of acute otitis media (AOM). A few randomized controlled trials (RCTs) have found that administration of the pneumococcal conjugate vaccine (PCV) to infants is effective at decreasing episodes of AOM during infancy and early childhood. However, these RCTs were in high-income countries in populations with a relatively low burden of suffering due to otitis media. This trial is the first to use data from a randomized trial to investigate the effectiveness of a PCV at decreasing otitis media in a country with a high level of morbidity and mortality due to otitis media. Methods: The effects of the 7-valent PCV and Haemophilus influenzae type b (Hib) conjugate vaccine on AOM with TM perforation were compared through a secondary analysis of data that were collected during a blinded, randomized trial in Bangladesh in 2004 and 2005. Infants received vaccines at 6, 10, and 14 weeks of age and their caregivers were interviewed weekly from 6˗24 weeks of age. Caregiver report of ear drainage was considered to represent AOM with TM perforation. Weekly interviews also asked about antibiotic use and other illness symptoms. Results: 340 infants were enrolled and randomized. Data were collected and analyzed for 328 infants. Baseline data were comparable between the two groups. In the PCV and Hib vaccine groups there were similar numbers of episodes of AOM with TM perforation and similar numbers of infants who had one or more episodes. However, in the PCV group there were fewer positive weekly reports of AOM with TM perforation total. Infants in the PCV group had an average of 1.2 weekly reports per episode, compared to those in the Hib vaccine group who had an average of 2.6 weekly reports per episode (p = 0.005). In the PCV group antibiotics were given during the first week of an episode of AOM with TM perforation in 82% of weeks compared to only 25% of such weeks in the Hib vaccine group (risk difference: 57%, 95% C.I. 23% - 90%). A multivariate analysis that accounted for the type of vaccine and for antibiotics given during the first week of an episode found that neither had a statistically significant effect on the number of weekly reports per episode of AOM with TM perforation (p= 0.10 for vaccine type, p= 0.33 for antibiotics). Conclusions: The results suggest that the 7-valent PCV does not cause a statistically significant difference in the incidence or duration of episodes of AOM with TM perforation among infants in Bangladesh. However, due to significant concerns about the internal validity of the study, the accuracy of these results is unclear and they should be interpreted with caution. The potential for measurement errors, the use of the Hib vaccine in the comparison group, and the poor adherence to the intervention constitute the greatest concerns about the internal validity of the study. On March 21, 2015, Bangladesh added a 10-valent PCV to its national immunization program, creating the opportunity for the use of historical cohort studies to research this topic in the future.