Vaccination Coverage Among Children Aged 2 Years - U.S. Affiliated Pacific Islands, April-October, 2016.

Vaccine-preventable diseases (VPDs) cause substantial morbidity and mortality in the United States Affiliated Pacific Islands (USAPI).* CDC collaborates with USAPI immunization programs to monitor vaccination coverage. In 2016, USAPI immunization programs and CDC piloted a method for estimating up-to-date status among children aged 2 years using medical record abstraction to ascertain regional vaccination coverage. This was the first concurrent assessment of childhood vaccination coverage across five USAPI jurisdictions (American Samoa; Chuuk State, Federated States of Micronesia [FSM]; Commonwealth of the Northern Mariana Islands [CNMI]; Republic of the Marshall Islands [RMI]; and Republic of Palau). Differences in vaccination coverage between main and outer islands were assessed for two jurisdictions where data were adequate.** Series coverage in this report includes the following doses of vaccines: ≥4 doses of diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP); ≥3 doses of inactivated poliovirus vaccine (IPV); ≥1 dose of measles, mumps, and rubella vaccine (MMR); ≥3 doses of Haemophilus influenzae type B (Hib) vaccine; ≥3 doses of hepatitis B (HepB) vaccine; and ≥4 doses of pneumococcal conjugate vaccine (PCV); i.e., 4:3:1:3:3:4. Coverage with ≥3 doses of rotavirus vaccine was also assessed. Completion of the recommended series of each of these vaccines was <90% in all jurisdictions except Palau. Coverage with the full recommended six-vaccine series (4:3:1:3:3:4) ranged from 19.5% (Chuuk) to 69.1% (Palau). In RMI and Chuuk, coverage was lower in the outer islands than in the main islands for most vaccines, with differences ranging from 0.9 to 66.8 percentage points. Medical record abstraction enabled rapid vaccination coverage assessment and timely dissemination of results to guide programmatic decision-making. Effectively monitoring vaccination coverage, coupled with implementation of data-driven interventions, is essential to maintain protection from VPD outbreaks in the region and the mainland United States.