Adolescent Vaccination Uptake Among Students Participating In Tdap-Only Clinics In Deschutes County, Oregon

Background:  In 2008, Tdap (tetanus toxoid, diphtheria toxoid, acellular pertussis) vaccine was added as a school entry requirement for children entering 7^th and 8^th grade in Oregon.  Many local health departments provided Tdap through school-located vaccination clinics in 2008, using vaccine provided at no cost by the Oregon Immunization Program.  A condition of receiving free vaccine was that all administered doses had to be entered in Oregon’s Immunization Information System (IIS).

Objectives:  To examine uptake of all adolescent- recommended vaccines among children who received Tdap in a school setting.

Methods:  OR IIS data were used to describe receipt of all vaccines routinely recommended for adolescents (Tdap, meningoccocal conjugate vaccine (MCV4), Human Papillomavirus vaccine (HPV), 2^nd dose Varicella vaccine) who received Tdap in school settings in Deschutes County in 2008.  Vaccine uptake was assessed using 2010 data, when participating adolescents were 12-17 years old.

Results:  1153/5380 (21%) adolescents received Tdap in school in Deschutes County in 2008. 589 (51%) were female; 292 (25%) were 10-11 years old, 761 (66%) were 12-13 years, and 100 (9%) were 14-15 years.  According to the IIS, as of October 2010, 803/1153(70%) had received no other recommended adolescent vaccines and 30% had received at least one other recommended vaccine. Among 1153 who received Tdap, 193 (16.7%) ever received MCV4, 239 (21%) ever received a second dose of Varicella, 155/589 females (26%) ever received ≥1 dose of HPV, and 62/589 (11%) received all 3 doses of HPV.

Conclusions:  A significant proportion of adolescents participating in the school-located Tdap clinics had no record of receiving other recommended vaccines.  Further study is needed to determine how school-located clinics impact adolescent vaccine uptake. Uptake among this group will be compared to a representative sample of adolescents from Deschutes County to examine differences in uptake between these groups, as well as issues related to IIS reporting.