Vaccine Candidate for Herpes Virus Complex 2

Herpes 1 and 2 are known as herpes simplex virus, where herpes 1 is most known as the common cold sores around your mouth whereas herpes 2 generally causes more cases of genital warts. Herpes can be transmitted sexually and non-sexually (think kissing a child on the mouth with an active open cold sore infection). Herpes 2 however is known to be more of a sexually transmitted disease and can be passed on to sexual partners and newborns who have infected mothers. Though as of right now there is not a vaccine against HSV-2, there is a promising study which is targeting "nucleoside-modified mRNA in lipid nanoparticles that encodes HSV-2 glycoproteins C, D and E" (Awasthi et. al., 2019). This candidate vaccine worked in mucine and guinea pigs, preventing them from developing genital lesions. Given the combination of glycoprotein D as well as two immune evasion molecules - binding glycoprotein C which binds complement C3b as well as glycoprotein E, Immunoglobulin G in inhibited. These three HSV-2 proteins were segregated in the hopes of increasing the effectiveness of the vaccine by inhibiting Immunoglobulin G fc activity. Though IgG is known to activate an immune response, it depends on whether the antigen or antibody is activated. For this vaccine, the IgG fc is inhibited, which inhibits an antibody bridge from forming. This antibody bridge leads to an anti-drug antibody, which inactivates the therapeutic effects of the targeted drug, which is why we specifically want to target the IgG fc receptor.

Since this vaccine has shown to work well  in animals, the next step will hopefully be clinical human trials. With that hopefully coming into fruition, there are some ethical questions to consider for those who have HSV-2 and for those who may come into contact with those infected. Is it more likely that if those with HSV-2 get this vaccine, that they will withhold their status from future potential sexual partners? Is it reasonable for the unaffected partners to potentially receive the vaccine to prevent transmission? Is that going overboard if the partner infected has had the vaccine? Also, most STD tests do not test for HSV strains unless specifically asked for, and since HSV can go dormant for a long while, many people may not even know they are affected. Like the HPV vaccine, should then everyone receive this HSV-2 vaccine to either prevent transmission or reduce the incidence of lesions? Once more is understood about this vaccine, I don't think it's a terrible idea for the population to receive it much like the HPV vaccine is being recommended; that's if however this vaccine is geared to people who are also not yet infected. Given the stigma that STDs have had on society, I think this is a promising next step in potential candidate vaccines.

References:

       Awasthi, S., Hook, L.M., Pardi, N., Wang, F., Myles, A., Cancro, M.P., Cohen, G.H., Weissman, D., Friedman, H.M. (2019). Nucleoside-modified mRNA encoding HSV-2 glycoproteins C, D and E prevents clinical and subclinical genital herpes. Science Immunology. 4.39. eaaw7083. doi: 10.1126/sciimmunol.aaw7083

      Lin, X., Lubinski, J.M., Friedman, H.M. (2003). Immunization strategies to block herpes simplex virus type 1 immunoglobulin G Fc receptor. Journal of Virology. 78. 5. 2562-2571. doi:10.1128/JVI.78.5.2562–2571.2004