Vaccine  previously found effective now  fails to protect women with HSV-2 affliction  and seems to be a cause of concern.

Team@CMHF

A once-promising vaccine against herpes viruses has failed in a large clinical trial, researchers reported.

The vaccine had markedly reduced the risk of genital herpes disease in women in so-called serodiscordant couples, in which one partner had the virus and other did not, according to Robert Belshe, MD, of St. Louis University in St. Louis, Mo., and colleagues.

But in a large study intended to mimic the general population of uninfected women, vaccine efficacy against disease was only 20%, the researchers reported.

The vaccine showed some efficacy against herpes simplex-1 (HSV-1), but not against herpes simplex-2 (HSV-2), the researchers reported.

Since both viruses are common and clinically indistinguishable, Leone said, the vaccine probably would have a limited public health benefit and won’t be pursued.

He said researchers probably will need to take a “different type of vaccine approach” in order to find something that works against both viruses.

In general, HSV-2 is regarded as more worrisome since it tends to recur more than HSV-1 and also is associated with an increased risk of acquiring HIV.

In the two earlier clinical trials, among discordant couples, the vaccine showed efficacy of 73% and 74% against genital disease (caused by either virus) among women who did not have antibodies against HSV-1 or HSV-2. There was no effect in men.

Analysis showed:

• Overall, the vaccine was just 20% efficacious in preventing genital herpes disease
• It was 58% efficacious against disease caused by HSV-1 but had no effect against HSV-2 disease
• Overall, the vaccine protected against infection with an efficacy of 22%, but that was driven by a 35% efficacy against HSV-1 infection. There was no effect against HSV-2 infection

The researchers noted that the findings are “puzzling in view of the previous two studies involving discordant couples” — both of which showed efficacy against HSV-2.

Interestingly, there were only two cases of HSV-1 disease in those two studies (one in each), the researchers noted, so that it was impossible to evaluate efficacy against that virus.

Ref: http://www.medpagetoday.com/InfectiousDisease/Vaccines/30505?utm_medium=email&utm_campaign=DailyHeadlines&utm_source=WC&email=drsumanrao21@gmail.com&eun=g371326d0r&userid=371326&mu_id=