An assessment of PCV13 vaccine coverage using a repeated cross-sectional household survey in Malawi.

ABSTRACT

Background: The 13-valent pneumococcal conjugate vaccine (PCV13) was introduced in Malawi from November 2011 using a three dose primary series at 6, 10, and 14 weeks of age to reduce Streptococcus pneumoniae-related diseases. To date, PCV13 paediatric coverage in Malawi has not been rigorously assessed.  We used household surveys to longitudinally track paediatric PCV13 coverage in rural Malawi. Methods: Samples of 60 randomly selected children (30 infants aged 6 weeks to 4 months and 30 aged 4-16 months) were sought in each of 20 village clinic catchment 'basins' of Kabudula health area, Lilongwe, Malawi between March 2012 and June 2014. Child health information was reviewed and mothers interviewed to determine each child's PCV13 dose status and vaccine timing. The survey was completed six times in 4-8 month intervals. Survey inference was used to assess PCV13 dose coverage in each basin for each age group. All 20 basins were pooled to assess area-wide vaccination coverage over time, by age in months, and adherence to the vaccination schedule. Results: We surveyed a total of 8,562 children in six surveys; 82% were in the older age group. Overall, in age-eligible children, two-dose and three-dose coverage increased from 30% to 85% and 10% to 86%, respectively, between March 2012 and June 2014.  PCV13 coverage was higher in the older age group in all surveys. Although it varied by basin, PCV13 coverage was consistently delayed median ages at first, second and third doses were 9, 15 and 21 weeks, respectively. Conclusion: In our rural study area, PCV13 introduction did not meet the Malawi Ministry of Health one-year three-dose 90% coverage target, but after 2 years reached levels likely to reduce the prevalence of both invasive and non-invasive paediatric pneumococcal diseases. Better adherence to the PCV13 schedule may reduce pneumococcal disease in younger Malawian children.