Vaccine coverage can be greatly improved, study says

A new study has demonstrated that vaccine coverage can be significantly improved through the proper interpretation of a combination of administrative and survey data.

The study, conducted by researchers from the Johns Hopkins University Bloomberg School of Public Medicine, was recently featured in the October 2011 issue of PLoS Medicine, according to

The researchers found that current measurements used to determine the success of vaccination campaigns can be seriously flawed and are often inconsistent.

"Reliable estimates of vaccination coverage are key to managing population immunization status," Justin Lessler, the lead author of the study, said, reports. "Currently, the performance of routine and supplemental immunization activities is measured by the administrative method, which leads to coverage estimates that are often inconsistent with the proportion reporting vaccination in cross-sectional surveys.”

The study further found that the administrative method does not properly account for the number of people that are systematically missed during a vaccination campaign.

The new method, which uses cross-sectional surveys of vaccine coverage combined with administrative data, showed significantly lower vaccination rates for three African countries - Sierra Leone, Madagascar and Ghana - than World Health Organization and UNICEF estimates.

“Estimates of the inefficiency of past vaccination activities and the proportion not covered by any activity allow us to more accurately predict the results of future activities and provide insight into the wars in which vaccination programs are failing to meet their goals,” Lessler said, according to