Comments on ‘‘Monitoring vaccination coverage: Defining the role of surveys”

Response to an article - Dear Editors,

Felicity Cutts and co-authors [Vaccine 34 (2016) 4103–4109]

provide a good overview of the role of household surveys in monitoring

of immunization coverage. More should be said, however,

about the optimal monitoring strategy for lower coverage

countries.

The most recent WHO/UNICEF estimates of national immunization

coverage (WUENIC) suggest that for 26 (57%) of 46 countries

with 2015 DTP3 coverage below 85%, the administrative data

over-estimate coverage by from 10 percentage points to as much

as 40 percentage points.1 Of course, as the article points out, coverage

surveys provide an imperfect ‘‘gold standard” with which to

assess even national (let alone sub-national) immunization coverage.

However, when national coverage is low it is essential to periodically

attempt to validate the administrative coverage estimate

with an estimate from a high quality nationwide household

survey.