Vical Incorporated, a San Diego-based gene-based treatment and vaccine company, announced the results on Monday of a study testing its Vaxfectin-formulated plasmid DNA herpes vaccine on guinea pigs.
The vaccine candidate was meant to protect against herpes simplex virus type two, the more serious of the two serotypes of herpes simplex. Approximately 25 percent of the U.S. population is seropositive for HSV-2 by the age of 40, Seeking Alpha
The company tested multiple variants of the vaccine and found that Vaxfectin-gD2/UL46/UL47 was the most successful in reducing latent viral load of herpes simplex. The variant was also able to reduce both recurrent disease and viral shedding in the genital tract.
"The observation that therapeutic immunization with Vaxfectin-gD2/UL46/UL47 significantly reduced the frequency of virus shedding has public health implications given that this is thought to be a major source of transmission," the authors of the study said, according to Seeking Alpha
The authors said that the success of the Vaxfectin variant strongly suggests that it warrants development as a therapeutic vaccine and should be moved into clinical trials. The company anticipates that the HSV-2 vaccine could enter clinical trials in the second half of 2013.
The study says that while immunization reduced the potential for viral transmission by reducing the frequency of genital tract shedding, the potential for infection by exposure during a shedding event is not lessened.
There is currently no cure for genital herpes, Seeking Alpha
Viral is developing the vaccine candidate under a grant from the National Institute of Allergy and Infectious Diseases.
The study was published in the journal Vaccine.