Herpes

Herpes simplex viruses (HSV)  type 1 and 2 causes lifelong latent infections that can lead to recurrent painful blisters. HSV-1 is common (infecting 40-60% of people)¹ , and predominantly induces lip, mouth and facial blisters, or the genitalia. HSV-2 is more usually sexually transmitted and affects the genitalia in about 20% of the population, but can also infect the oral mucosa. Although the disease is more a social burden than a serious disease, primary herpes infection can be devastating for newborn children, and HSV can cause serious complications in immune-compromised individuals, especially HIV/AIDS patients.

Both viruses are closely related immunologically, and infection with one type partially protects against the other.

Infection leads to life-long latency and periodic reactivations occur that can lead to the shedding of live virus. Although therapeutic drugs are available, their efficacy is limited and there is not currently a vaccine against these viruses.

Mymetics' HSV vaccine approach

Vaccine candidates based on live attenuated viruses have all failed clinical trials. Several preparations of isolated glycoproteins, combined with one or more adjuvants have provided some degree of protection in clinical trials.

Mymetics is developing a preventive HSV-1 and -2 vaccine, consisting of virosomes and adjuvants.

Latest Results and Next Steps

Exploratory experiments were performed on mice in which the immunogenicity of HSV-1 virosomes is investigated, following injections through various routes (intra-muscular and intra-nasal).

The next stage of research will focus on the development of new virosomes. If results are confirmed, up-scale and GMP production will be investigated with mandatory toxicity evaluation in animals. A small Phase I clinical trial in a population of seronegative subjects to HSV to assess the safety and tolerability of the vaccine should take place soon after toxicology studies.

References

¹Datamonitor; Commercial Insight: Select Herpes Viruses and Human Papilloma Virus; (August 2008)