that trimethylpsoralen damage stimulates recombination. MR of HSV appears to partially depend on the host cell recombinational repair machinery since skin fibroblast cells defective in a component of this machinery (i.e. cells from Bloom's syndrome patients) are deficient in MR. These observations suggest that MR in HSV infections involves genetic recombination between damaged viral genomes resulting in production of viable progeny viruses. HSV-1, upon infecting host cells, induces inflammation and oxidative stress. Thus it appears that the HSV genome may be subjected to oxidative DNA damage during infection, and that MR may enhance viral survival and virulence under these conditions. Use as an anti-cancer agent Modified Herpes simplex virus is considered as a potential therapy for cancer and has been extensively clinically tested to assess its oncolytic (cancer killing) ability. Interim overall survival data from Amgen's phase 3 trial of a genetically attenuated herpes virus suggests efficacy against melanoma. Use in neuronal connection tracing Herpes simplex virus is also used as a transneuronal tracer defining connections among neurons by virtue of traversing synapses. Other related outcomes HSV-2 the most common cause of Mollaret's meningitis. HSV-1 can lead to potentially fatal cases of herpes simplex encephalitis. Herpes simplex viruses have also been studied in the central nervous system disorders such as multiple sclerosis, but research has been conflicting and inconclusive. Following a diagnosis of genital herpes simplex infection, patients may develop an episode of profound depression. In addition to offering antiviral medication to alleviate symptoms and shorten their duration, physicians must also address the mental health impact of a new diagnosis. Providing information on the very high prevalence of these infections, their effective treatments, and future therapies in development may provide hope to patients who are otherwise demoralized. Research There exist commonly used vaccines to some herpesviruses, such as the veterinary vaccine HVT/LT (Turkey herpesvirus vector laryngotracheitis vaccine). However, it prevents atherosclerosis (which histologically mirrors atherosclerosis in humans) in target animals vaccinated. The only human vaccines available for herpesviruses are for Varicella zoster virus, given to children around their first birthday to prevent chickenpox (varicella), or to adults to prevent an outbreak of shingles (herpes zoster) . There is, however, no human vaccine for herpes simplex viruses. As of 2022, there are active pre-clinical and clinical studies underway on herpes simplex in humans; vaccines are being developed for both treatment and prevention. References External links Herpes simplex: Host viral protein interactions: