20 THE ADA PRACTICAL GUIDE TO EFFECTIVE INFECTION CONTROL Currently, two recombinant DNA hepatitis B vaccines are available in the United States — Recombivax HB and Engerix-B. Both vaccines are considered to be safe and effective in producing immunity to HBV. The vaccines are administered in three injections during a 6-month period — at 0, 1 and 6 months. Members of the dental team receiving the vaccine should be tested for antibody to HBV surface antigen (HBsAg) 1 to 2 months after completion of the 3-dose vaccination series. Persons who do not respond adequately to the vaccine should complete a second 3-dose series. Persons in whom a protective antibody response (greater than 10 mIU/ml) develops after vaccination are considered immune. If there is no antibody response after the second series, testing for HBsAg should be performed. Vaccine-induced antibodies gradually decline over time, and 60% of persons who initially responded to vaccination will lose detectable antibodies over 12 years. However, immunity continues to prevent clinical disease. Booster vaccines and periodic serological testing to monitor antibody levels after completion of the vaccine series are not necessary for vaccine responders. The 1991 Occupational Safety and Health Administration’s Bloodborne Pathogens Standard mandated that employers must offer the hepatitis B vaccine to employees without cost within their first 10 working days if they are potentially exposed at work to blood or OPIM. Employers are also required to ensure that employees who decline to accept HBV vaccination sign an appropriate declination statement. Employees who decline should also be told that they can accept the vaccine later, again, at no cost to the employee. Persons unable or unwilling to be vaccinated as required or recommended should be educated on their exposure risks, infection control policies and procedures for the facility, and the management of work-related illness and work restrictions (if appropriate) if exposed or infected. The 1991 Occupational Safety and Health Administration’s Bloodborne Pathogens Standard mandated that employers must offer the hepatitis B vaccine to employees without cost within their first 10 working days if they are potentially exposed at work to blood or OPIM.