A report published in the New England Journal of Medicine suggests that during a controlled lab test, a promising herpes vaccine failed to provide protection against herpes simplex-2 (HSV-2), disappointing researchers who had hopes that the vaccine could be used as genital herpes treatment, reports MSNBC.

The news channel notes that the experimental genital herpes shot proved effective against herpes type 1 (HSV-1), cause behind cold sores and rare genital herpes cases, but failed to show efficacy against herpes simplex-2 (HSV-2), the cause of genital herpes, leaving researchers struggling to determine their next course of action.

Expressing a disappointment of the failure, Dr. Peter A. Leone, an infectious disease specialist at the University of North Carolina, Chapel Hill and co-author of the research, told MSNBC that the vaccine will now have no market value due to its limited public health benefit, adding that there is a need of new and distant approach for developing a vaccine that works against both - HSV-1 and HSV-2.

A team of researchers randomly injected 8,000 women, aged 18 to 30, who were uninfected by either of the viruses, with herpes vaccine or hepatitis A vaccine, the cable news channel learns. After 20 months, study authors found new vaccine to be mildly effective against HSV-1, but ineffective in preventing genital herpes, one of the most common sexually transmitted infections, reports the US-based channel.

MSNBC notes that in two of the pervious clinical trials involving heterosexual couples, the vaccine showed an efficacy against both viruses among women, but failed to protect men from any kind of infection. Referring to the finding of earlier trails, Leone told the television channel that the vaccine effective against herpes-1 can help develop a future vaccine for treating both oral herpes and genital herpes.