B immunization among private health plans is unclear but is considered to be low (Eric Mast, CDC, Hepatitis Branch, personal communication, October 1996).
A recent economic analysis of various immunization strategies to prevent hepatitis B showed that perinatal prevention (screening of pregnant women and prophylaxis of infants) and routine infant immunization would reduce the 4.8 percent lifetime risk of hepatitis B virus infection by at least 68 percent, compared with a 45 percent reduction of lifetime risk for adolescent vaccination (Margolis et al., 1995). The authors concluded that adolescent vaccination of those who were not currently immunized should be considered part of a national strategy against hepatitis B virus infection.
With the exception of not having sexual intercourse with an infected partner, using a new latex condom during every act of sexual intercourse is currently the most effective method of preventing exposure to STDs (CDC, 1993b). When used correctly and consistently (during every act of intercourse), condoms are highly effectively against bacterial and viral STDs including HIV infection (Cates and Stone, 1992; Roper et al., 1993; Weller, 1993). Several studies that have followed ''discordant" partners show that consistent condom use significantly reduces the transmission of STDs including HIV infection (Laurian et al., 1989; European Study Group on Heterosexual Transmission of HIV, 1992).
Failure to use a condom correctly and consistently, rather than potential defects of the condom itself, is considered to be the major barrier to condom effectiveness (Cates and Stone, 1992; CDC, 1993b). Many incidents of condom breakage and leakage are associated with improper handling or inappropriate use of lubricants.
Data show that condom use has increased in the United States in the last few decades (DeBuono et al., 1990; Pleck et al., 1993; Peterson, 1995). Data from the National Survey of Family Growth show that, among women who had their first intercourse premaritally at 15-19 years of age, the proportion who used a condom at first intercourse rose from 28 percent during 1980-1982 to 55 percent during June 1988-November 1990 (Peterson, 1995). In addition, data from the CDC's Youth Risk Behavior Surveillance System show that, from 1990 through 1993, the proportion of high school students who reported using condoms at last sexual intercourse increased significantly from 46.2 percent to 52.8 percent (CDC, 1995a). Among unmarried sexually experienced women of reproductive age, approximately 30 percent reported using a condom for disease prevention every time or most times that they have intercourse (Anderson et al., 1996).
Although the first female condom was introduced in the 1920s, the polyurethane female condom has only recently been approved for use in the United States and represents an important alternative to the male condom (CDC, 1993b; IOM, 1996). A major advantage of the female condom is the greater control that