Although there are various treatment options available for herpes and they work well, medicine is an ever-changing science, and scientists and researchers experiment with novel drugs to provide more benefits to the patients and lessen the disease burden in the society. One such drug is Pritelivir.
The use of pritelivir under investigation for the treatment of herpes. Pritelivir is an inhibitor of the HSV-2 helicase-primase complex and acts through a different mechanism when compared to already available antiviral drugs available for herpes in the market (e.g., acyclovir, valacyclovir).
However, the US Food and Drug Administration (FDA) has put a hold on the clinical development of pritelivir because of unexplained skin (hair loss, dry crusty skin) and blood (anemia) toxicities in monkeys, despite positive findings in two studies. In a clinical study, pritelivir was associated with significantly less viral shedding compared with valacyclovir. Moreover, patients receiving pritelivir had fewer days with genital lesions. However, the drug is still under research and may or may not be available for use in the future, depending on its safety and efficacy.
Vaccine Development
Several therapeutic vaccine trials have been carried out to “boost” natural immunity in persons with a known history of HSV-2 infection to reduce the risk of recurrent infection. A clinical trial of the gD2/alum vaccine showed that immunization of HSV-2 seropositive persons with a history of genital herpes reduced the number of recurrences (0.42 per month in vaccines versus 0.55 in placebo recipients) [1].
However, two other studies did not demonstrate any clinical benefit [2,3]. Several therapeutic HSV-2 vaccine trials are currently under investigation, and two vaccines have shown limited efficacy in reducing viral shedding following immunization. Additional research studies of these vaccines to optimize the dose, dosing schedule and the effect on recurrences are underway.
Circumcision Status
Circumcision has been affiliated with a decreased risk of acquisition of some infectious agents, for instance, HIV. A clinical trial of circumcision in Uganda (that was aimed at decreasing HIV transmission) showed a 28 percent reduction in HSV-2 incidence among study participants in the arm that had circumcision. [4].
Tenofovir
A variety of topical and oral agents are currently under investigation for the prevention of herpes simplex virus-2 (HSV-2) acquisition and shedding of virus [5]. For example, tenofovir, when used for HIV pre-exposure prophylaxis (PrEP) to an HSV-2 negative patient, may also reduce the risk of acquiring HSV-2.
The effect of vaginally administered tenofovir gel on acquiring HSV-2 infection was evaluated in a study of HSV-2- negative women from South Africa who participated in a clinical trial designed to assess the efficacy of this drug in reducing the acquisition of HIV infection [6].
The incidence of HSV-2 infection was notably decreased in the group that received tenofovir gel compared with the group that received just a placebo drug. However, we cannot confidently say if tenofovir gel has a role in decreasing viral shedding among women with HSV-2 infection.
In a randomized study of 64 immunocompetent women with symptomatic HSV-2 infection, tenofovir vaginal gel did not remarkably reduce viral shedding or the number of days with genital lesions [7]. Therefore, further studies are warranted before these agents can be recommended for HSV-2 prevention in routine care.
REFERENCES
- https://www.ncbi.nlm.nih.gov/pubmed?otool=flumrlib&term=7911177
- https://www.ncbi.nlm.nih.gov/pubmed?otool=flumrlib&term=9359709
- https://www.ncbi.nlm.nih.gov/pubmed?otool=flumrlib&term=16213066
- https://www.ncbi.nlm.nih.gov/pubmed?otool=flumrlib&term=16581731
- https://www.ncbi.nlm.nih.gov/pubmed?otool=flumrlib&term=17877886
- https://www.ncbi.nlm.nih.gov/pubmed?otool=flumrlib&term=26244306
- https://www.ncbi.nlm.nih.gov/pubmed?otool=flumrlib&term=26044291
