In the 5 years since the ACIP had recommended that gay men, injection drug users, health care workers, and select immigrants be vaccinated against the infection, hepatitis B prevalence had not decreased but rather increased, with rates particularly high among young adults. Incrementally, federal recommendations evolved in response. In 1988, the ACIP recommended that all pregnant women be tested for hepatitis B, and, if positive, their infants vaccinated within 12 h of birth to prevent transmission to the next generation. When disease incidence persisted at high rates, the ACIP altered its strategy again, recommending universal infant vaccination against hepatitis B in 1991. Health officials acknowledged that the new strategy was necessary “because vaccinating persons engaged in high-risk behaviors, life-styles or occupations…has not been feasible” and because many infected people had “no identifiable source for their infections.”