challenged mice (Hilleman et al., 1981.) Such vaccines also induce antibody in humans (Hilleman et al., 1981). Studies are underway to measure the vaccine’s ability to prevent infection in adults not previously infected with HSV-2 whose sexual partners suffer from recurrent genital herpes (Mertz et al., in press).
The glycoprotein vaccines are being actively pursued by a number of groups working to prevent herpesvirus infections and disease in man. The current thrust is to prepare the glycoproteins by recombinant DNA techniques in host species such as yeast or mammalian cell cultures (Gunby, 1983; Lasky et al., 1984). The ultimate vaccine probably will include at least two glycoproteins each from serotypes 1 and 2.
Advances in molecular biology also have made possible the development of genetically engineered attenuated live virus vaccines against HSV (Roizman et al., 1984). These vaccines, which have been tested in experimental animals, are expected to produce longer lasting immunity than the subunit vaccines. Some researchers believe that objections to the use of live HSV vaccines will diminish as genetic engineering makes possible the removal of regions of the genome responsible for cell transformation.
Clinical trials of vaccine candidates pose no major problems with regard to study populations because sexual partners of persons already infected provide an easily identifiable and accessible test group.
The health belief model parameters (perceptions of risk of illness, severity, vaccination benefits, and barriers) used to predict vaccine utilization are described in Chapter 6, where scores assigned to various vaccines are displayed together to ease comparison.
The perception among parents of the risk of illness caused by HSV-1 and HSV-2 to their children is believed to be low to moderate. The perception of the clinical and social consequences of the associated illnesses (possibly with some physican cueing on CNS complications) have been rated as moderately high. Perceptions of the benefits of vaccination probably also would be moderately high because there are no cures for these diseases. Several potential barriers exist, however, including the long delay in some of the major benefits from childhood to the sexually active adult years; the realization by parents that they would be protecting their children against a disease for which the risk rises with promiscuity; and the probable number of injections involved in maintaining immunity through early adult life.
Differences between lay perceptions of glycoprotein and live attenuated vaccines are expected to be minimal.