Tdap Coverage Rates During a Major Pertussis Outbreak: Results From a Cross-Sectional Survey of Adults In San Diego County

Background:  California is currently experiencing a record number of Pertussis cases statewide.

Objectives:  Estimate adult Tdap vaccination coverage rates for San Diego County and analyze factors associated with the Tdap receipt, as well as, identify attitudes and beliefs towards the Tdap vaccine.

Methods:  Surveys were collected by computer-assisted random digit dial telephone survey (RDD) from July -October 2010. Eligible households were within San Diego County and had an adult 18-64 years of age at the time of the survey. 

Results:  The overall coverage rate of Tdap for the 1,281 participants aged 18-64 was 25%, a significant increase from 13% in 2009. However, among various subsets of the population coverage rates ranged from 19% for Whites 50-64 years old to 42% for Healthcare Workers. Adults with a child less than 12 months of age in the home had a coverage rate of 39%, significantly higher than those without a child of that age in the home (24%).   The younger Hispanic population (18-49) had the lowest coverage rate of Tdap among ethnicities (22% vs.27% White vs. 36% Other).  However, the older Hispanic population (50-64) had the highest coverage rate of 36%. When asked the main reason for not receiving the Tdap vaccine 66% responded they didn’t know they needed it/ hasn’t been recommended.

Conclusions:  Despite the improvement in adult Tdap coverage rates, more progress needs to be made overall. The recent epidemic of pertussis and associated media coverage provides an opportunity for focused efforts to educate the public, particularly adults who have contact with the vulnerable population of infants. Along with educating the general public, encouraging healthcare providers to be proactive about recommending and vaccinating patients should be included in the plan to improve coverage rates.