I know this sounds rather startling (but it does get your attention): Most of us have probably or will have a herpes simplex infection. There are two major herpes simplex viruses: herpes simplex 1 (HSV-1) and herpes simplex 2 (HSV-2). Although HSV-1 is the “one” that commonly causes the cold sores we get on our lips and mouth, especially when our immune guard is down, it can also cause genital disease. Herpes 2 is the more “classic” cause of genital herpes. (For more complete information on herpes see my article “Shedding the Herpes Virus: Even when you don’t know you have it” archived on my website judithreichman.net.)

Many of us have had our first bout of HSV-1 in childhood (and developed cold sores), but epidemiologists are now finding that more and more HSV-1 infections occur later in life, causing genital disease in young adults. The type of herpes that is present “up there”, or “down there” can be differentiated through a blood test for specific type 1 or type 2 antibodies. (The test is aptly termed Herpes Select.) However, most HSV infections occur without symptoms and only 10 to 20% of persons with antibodies to HSV-2 have recurrent disease. That’s why HSV is so easily spread, the virus can be shed without a lesion, is highly contagious and voila, sexual contact allows it to pass to and infect a partner.

As usual I spent part of my weekend perusing medical journals. The most interesting articles (for me) are often found in general medical journals, and sure enough there was one that appeared in the January 5th JAMA titled “Efficacy Results of a Trial of Herpes Simplex Vaccine”

There was a time before we became so concerned about the spread of HIV and HPV, when patient and doctor concerns were focused on herpes. The question commonly posed to gynecologists was “if we can put a man on the moon, why can’t we develop a herpes vaccine?” And we, the ObGyn’s would sadly bow our heads and admit research failure. Well the researchers are still working on developing that vaccine… The study reported in this article was supported by the National Institute of Allergy and Infectious Diseases and the pharmaceutical company GlaxoSmithKline. (Guess why the latter corporation is interested.)

The study of the efficacy of the herpes vaccine that they had tried to develop was appropriately performed. It was randomized, double-blinded and included 8323 women ages 18 to 30 that were negative for antibodies for HSV-1 and HSV-2. These women were divided into 2 groups and either received the investigational herpes vaccine at months 0, 1 and 6 or a control vaccine (which was an inactivated hepatitis A vaccine) on those 3 occasions. The women were then followed for development of HSV-1 or HSV-2 from one month after the second dose through month 20.

Although the study doesn’t seem that huge, it was…it was carried out at 50 clinical sites in the United States and Canada: 31,770 women were screened for antibodies to HSV-1 and HSV-2 and 12,468 were negative. From the latter group, 8323 women met eligibility criteria (I guess they agreed to take the three injections and could be appropriately followed) and were then enrolled.

The researchers found that, overall; the vaccine was 55% effective against HSV-1 infection but was not effective against HSV-2 infections even though it produced antibodies against HSV-2. They weren’t sure why. Rather than admit defeat (at least a type 2 defeat) the authors proposed the following: “Among the control subjects in the present study, 60% of the cases of genital disease and two thirds of the infections were caused by HSV-!….HSV-1 now rivals HSV-2 as a cause of neonatal herpes disease….and although the development of a vaccine that provides protection against HSV-1 genital disease is a substantial step forward, additional progress is needed before a herpes vaccine is likely to be approved for general use.”

In other words, we still don’t have that vaccine against herpes…even though we have put a man on the moon.