Herpes Simplex Virus Infections and Vaccine Advances
Pp. 25-36 (12)
Tu Thanh Mai,
Herpes simplex viruses belong to the subfamily Alphaherpesvirinae and the
genus Simplexvirus and have the capacity to establish latent infections in sensory
ganglia of humans. Intermittent reactivation of the virus can cause retrograde
transportation to the dermatome where initial infection occurred, the virus crosses into
the stratified squamous epithelium where it starts replicating again. Herpes simplex
viruses that cause infections in humans are HSV-1 (infection of the skin and oral
mucosa) and HSV-2 (sexually transmitted infection of the genital tract). Despite almost
a century old efforts to develop vaccine against HSV viral infection, results from
clinical trials in humans have been disappointing. Three main approaches were used to
develop the vaccine: glycoprotein vaccine (gB and gD), mutated inactivated live virus
and DNA vaccines. Although all vaccine candidates showed excellent results in animal
models, significant protection was not seen in human clinical trials. This not only
questions the validity of the animal models but also calls for a change in the current
strategies in designing future vaccine candidates.
In designing the vaccine candidates very little attention was devoted to the immune
evasion mechanisms of the virus that are the main reason that the virus is able to persist
and to reactivate when immune responses weaken.
Herpes, alphaherpesviridae, sensory ganglia, HSV-1, HSV-2,
glycoprotein, vaccine, immune evasion, latent infection, skin infection, genital
tract infection, viral envelope, DNA vaccine, STD, Simplexvirus, gB, gD, CD8+
T cells exhaustion, HERPEVAC, ICP4.