Researchers at the University of Florida have made a Hammerhead ribozyme that targets and cleaves the mRNA of essential genes in HSV-1. The hammerhead which targets the mRNA of the UL20 gene greatly reduced the level of HSV-1 ocular infection in rabbits and reduced the viral yield in vivo. The gene-targeting approach uses a specially designed RNA enzyme to inhibit strains of the herpes simplex virus. The enzyme disables a gene responsible for producing a protein involved in the maturation and release of viral particles in an infected cell. The technique appears to be effective in experiments with mice and rabbits, but further research is required before it can be attempted in people who are infected with herpes.
Another possibility to eradicate the HSV-1 variant is being pursued by a team at Duke University. By figuring out how to switch all copies of the virus in the host from latency to their active stage at the same time, rather than the way the virus copies normally stagger their activity stage, leaving some dormant somewhere at all times, it is thought that conventional anti-viral drugs can kill the entire virus population completely, since they can no longer hide in the nerve cells. One class of drugs called antagomir could serve this purpose. These are chemically engineered oligonucleotides or short segments of RNA, that can be made to mirror their target genetic material, namely herpes microRNAs. They could be engineered to attach and thus 'silence' the microRNA, thus rendering the virus incapable to keep latent in their host. Professor Cullen believes a drug could be developed to block the microRNA whose job it is to suppress HSV-1 into latency.
One vaccine that was under trial was Herpevac, a vaccine against HSV-2. The National Institutes of Health (NIH) in the United States conducted phase III trials of Herpevac. In 2010, it was reported that, after 8 years of study in more than 8000 women in the United States and Canada, there was no sign of positive results against the sexually transmitted disease caused by HSV-2 (and this despite earlier favorable interim reports).
A laboratory at Harvard Medical School has developed dl5-29 (now known as ACAM-529), a replication-defective mutant virus that has proved successful both in preventing HSV-2/HSV-1 infections, and in combating the virus in already infected hosts, in animal models. It has been shown that the replication-defective vaccine induces strong HSV-2-specific antibody and T-cell responses; protects against challenge with a wild-type HSV-2 virus; greatly reduces the severity of recurrent disease; provides cross-protection against HSV-1, and renders the virus unable to revert to a virulent state or to become latent. His vaccine is now being researched and developed by Accambis (acquired by Sanofi Pasteur in September 2008), and is due to be applied as an Investigational New Drug in 2009. However, the status of ACAM-529 became after the acquisition somewhat unclear. According to Jim Tartaglia, a company representative of Sanofi Pasteur, ACAM-529 is still under development and should be enter phase I clinical testing in 2012.
A private company called BioVex began Phase I clinical trials for ImmunoVEX, another proposed vaccine, in March 2010. A completely new approach has the "HSV-2 ICP0 live-attenuated HSV-2 vaccine" investigated by Dr. William Halford at the Southern Illinois University (SIU) School of Medicine.