Hepatitis B Vaccination Among Research Participants, Seattle, Washington

The authors report on a protocol to increase hepatitis B virus vaccination among participants in two research studies in Seattle. Researchers interviewed and screened injection drug users in a cohort study for blood borne viral infections, including HBV. Participants learned their results at post-test counseling, at which time they also received risk reduction counseling and medical services referral. Although only 14 percent of participants reported prior HBV vaccination, the prevalence of the core antibody, anti-HBc, was 67 percent.

Anti-HBc negative participants took away vouchers for a no-cost series of HBV vaccinations at a downtown Seattle public health clinic that agreed that people with vouchers would be accepted on a drop-in basis. The clinic also pledged to reduce waiting time and to record the number of vouchers participants redeemed. Researchers distributed 120 vouchers between February and December, 1997. Among participants with vouchers, 91 (76 percent) completed no vaccinations; 6 (5 percent) completed 1 vaccination; and 5 (4 percent) completed 2. Eighteen participants (15 percent) completed the full series of 3 HBV vaccinations.

The Young Men's Survey in 1998 studied men ages 15 to 22 who attended Seattle same-sex venues. YMS participants received counseling and testing for HIV and HBV. Thirty-two percent were surface-antibody positive; five percent were anti-HBc positive. Researchers counseled HBV-susceptible study subjects at the post-test visit and gave them vouchers for free vaccinations at a health department clinic. This clinic's staff recorded when the first voucher was redeemed but could not keep track of subsequent vaccinations. Of 285 YMS participants with vouchers, only 9 (3 percent) initiated vaccination.

A study of injection drug users in Anchorage, Alaska, gave a $10 incentive for participants to complete their first vaccination at off-site locations. The percentage of completion rose from 7 percent to 48 percent.

Higher completion rates occur on-site at needle exchanges, drug treatment centers, and HIV counseling and testing programs. However, research field offices may not be able to provide on-site service unless medically licensed personnel are there to administer the vaccinations. Previous studies have also cited frequent missed opportunities, in health-care settings, to vaccinate injection drug users and men who have sex with men.

Screening research study participants for HBV could contribute to HBV prevention by raising awareness of the need for vaccination and identifying gaps in local public and private health services. Research findings in the first two studies contributed to the decision to assign a public health nurse for on-site vaccination at the Seattle needle exchange. Results of the study were used to develop a local vaccination campaign for gay men.

The authors conclude that HBV screening and no-cost vaccination referrals provided by research studies might not be enough to achieve acceptable vaccination levels. Additional strategies -- which may include monetary incentives -- need to be implemented.

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