Lack of compliance with hepatitis B vaccination among Canadian STD clinic patients: candidates for an accelerated immunization schedule?

Most studies looking at the effectiveness of vaccination programs have been based on the postvaccination response among health care workers, infants, public safety personnel, and haemodialysis patients. 3-7 In 1991, the Ontario Ministry of Health expanded its free hepatitis B vaccine program to include high risk groups, comprising homosexual/bisexual men, heterosexual people having multiple sexual partners, injection drug users, and STD clinic atten-dees. A vaccination program for STD clinic clients may be problematic since these vaccinees may not be as likely as health care workers to complete the vaccination series. To determine the effectiveness and any limitations of a hepatitis B vaccination program in an STD clinic, we studied our clinic attendees in Hamilton, Ontario, from July 1992 to March 1994. A total of 853 consecutive clients with a mean age of 27.1 (SD 9.9) years, 66% of whom were male, were approached by the public health nurse at the clinic and offered vaccination free of charge (Engerix-B, SmithKline Beecham Pharma Inc., Oakville, ON) on a schedule of three doses given at 0, 1 and 6 months. The clinic receptionist gave clients a reminder card for their next appointment, and mailed reminders to clients who were more than two months late for their second dose. A reminder letter was not sent for the third dose. Often, the clients agreed to receive the first dose at the time of the serologic testing. Of the 853 clients, 668 (78%) agreed to testing for anti-HBs and HbsAg, and 611 (91%) were seronegative for both. No clients tested positive for HbsAg. In a subset of 212 consecutive clients who were tested for both anti-HBc and anti-HBs, 10 people were positive for anti-HBc, 9 of whom were also positive for anti-HBs. Five hundred and fifty (90%) of the seronega-tive clients were vaccinated (20 mcg/1 mL) intramuscularly in the deltoid area. The presence or absence of antibodies was determined for 150 people at the time of the third dose (after two doses), and 22 (15%) of them did not have anti-HBs. The 85% seroconversion (seronegative to seropositive) rate after the second dose was higher than in other studies, which report about 33% 8 to approximately 70% 9 and 79% 10 of vaccinees seroconverting after two doses. Seventy of 88 men (80%) and 58 of 62 women (94%) had detectable antibodies after the second dose of vaccine (p=0.03). Titres were determined for only 91 of the 128 …