While the HPV vaccine continues to garner attention and controversy, scientists continue to work on creating vaccines for other sexually transmitted diseases. The search for a vaccine to prevent Herpes faced a setback this month, when researchers published findings in the New England Journal of Medicine from a double-blind, placebo-controlled trial that found a new vaccine to be useless against Herpes Simplex Virus 2 (HSV-2).
HSV-2 is the virus which is primarily responsible for genital herpes though the disease can be caused by HSV-1, a different strain of the virus which more often causes oral herpes or cold sores to appear on the lips. Both strains are sexually transmitted and can cause painful sores to appear on an individual’s genitals. Many people infected with Herpes will never have an outbreak and may never be aware that they are infected while others will have recurrent outbreaks throughout their lives.
According to the Centers for Disease Control and Prevention (CDC) a nationally representative study found that 16.2 percent of people ages 14 to 49 in the Untied States, or about one out of six, have HSV-2 infection. The CDC does say that the percentage of adults in the United States infected with HSV-2 has remained stable for many years. Nonetheless, a vaccine to prevent the spread of this potentially painful disease would be a major step forward.
Two previous studies of a HSV-2 vaccine suggested that it might be effective. For this study, researchers randomly assigned 8,323 uninfected women ages 18 to 30 to receive the herpes vaccine or a placebo. (Researchers used the shot for hepatitis A as the placebo.) The study found that after 20 months, there was no significant difference in HSV-2 infection rates between the vaccine and placebo groups. The vaccine did provide some protection against HSV-1 genital infections.
One of the study’s authors suggested that it might be time to change course. “The failure of the vaccine really suggests that we need to look at new approaches to HSV vaccine development,” said Dr. Peter A. Leone, an author of the study and professor of medicine at the University of North Carolina. An attenuated virus, like that used in vaccines against chickenpox, may prove more effective.