Immunizing school-age children and adolescents: experience from low- and middle-income countries

Given the increased attention on the need for booster immunizations of older children and adolescents, as well as new primary vaccine series that specifically target school-age children and adolescents, we reviewed the current state of vaccine delivery to school-age children and adolescents in low- and middle-income countries.

We searched the published literature and unpublished sources for articles, meeting presentations, technical reports and program documents related to immunization policies and programs for school-age children and/or adolescents between 6 and 19 years of age in low- and middle-income countries.

We found several examples of ongoing school-age children and adolescent immunization in low- and middle-income countries. Reasons to vaccinate this age group include vaccines specifically targeted for this age group, waning immunity from prior vaccination, "catch-up" vaccination, acceleration of disease control or elimination efforts, and age distribution shift in the incidence of vaccine-preventable diseases. Multiple delivery strategies are currently in use: routine immunization, supplementary immunization activities, and Child Health Days and similar activities. Vaccines can be delivered in fixed sites, or through outreach. Most immunization programs that target adolescents and school-aged children are providing boosters of infant vaccines at school entry age, with scant experience in delivery of primary vaccination series in adolescents. Few of these programs have been formally evaluated and dissemination of lessons learned is limited.

This baseline description may facilitate immunization program planning in countries considering vaccinating this age group. Additionally, this summary may inform plans for operational research and program evaluation designed to expand vaccine delivery to school-age children and adolescents in low- and middle-income countries.