Article

Efficacy Results of a Trial of a Herpes Simplex Vaccine

Division of Infectious Diseases, Allergy, and Immunology, Saint Louis University, St. Louis, MO 63104, USA.
New England Journal of Medicine (Impact Factor: 55.87). 01/2012; 366(1):34-43. DOI: 10.1056/NEJMoa1103151
Source: PubMed

ABSTRACT

Two previous studies of a herpes simplex virus type 2 (HSV-2) subunit vaccine containing glycoprotein D in HSV-discordant couples revealed 73% and 74% efficacy against genital disease in women who were negative for both HSV type 1 (HSV-1) and HSV-2 antibodies. Efficacy was not observed in men or HSV-1 seropositive women.
We conducted a randomized, double-blind efficacy field trial involving 8323 women 18 to 30 years of age who were negative for antibodies to HSV-1 and HSV-2. At months 0, 1, and 6, some subjects received the investigational vaccine, consisting of 20 μg of glycoprotein D from HSV-2 with alum and 3-O-deacylated monophosphoryl lipid A as an adjuvant; control subjects received the hepatitis A vaccine, at a dose of 720 enzyme-linked immunosorbent assay (ELISA) units. The primary end point was occurrence of genital herpes disease due to either HSV-1 or HSV-2 from month 2 (1 month after dose 2) through month 20.
The HSV vaccine was associated with an increased risk of local reactions as compared with the control vaccine, and it elicited ELISA and neutralizing antibodies to HSV-2. Overall, the vaccine was not efficacious; vaccine efficacy was 20% (95% confidence interval [CI], -29 to 50) against genital herpes disease. However, efficacy against HSV-1 genital disease was 58% (95% CI, 12 to 80). Vaccine efficacy against HSV-1 infection (with or without disease) was 35% (95% CI, 13 to 52), but efficacy against HSV-2 infection was not observed (-8%; 95% CI, -59 to 26).
In a study population that was representative of the general population of HSV-1- and HSV-2-seronegative women, the investigational vaccine was effective in preventing HSV-1 genital disease and infection but not in preventing HSV-2 disease or infection. (Funded by the National Institute of Allergy and Infectious Diseases and GlaxoSmithKline; ClinicalTrials.gov number, NCT00057330.).

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Available from: Peter Leone, Apr 22, 2014
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    • "Efforts to prevent genital herpes using gD-2 subunit vaccines have been ongoing for the last 20 years at a cost in excess of $100 million[41]. To date, gD-2 vaccines have yielded ambiguous protection in clinical trials[18,40].Furthermore, no protection against acquisition or genital herpes disease was shown, despite high titers of neutralizing antibody[41]. The morbidity and socioeconomic burden associated with genital herpes as well as the alarming relationship between genital herpes and increased risk of acquiring HIV infection emphasize the need for the development of an effective vaccine[42]. "
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    ABSTRACT: The highly immunogenic glycoprotein D (gD) of herpes simplex virus type 2 (HSV-2) is a very important element for entry of this virus into host cells. These characteristics have made this protein a very interesting HSV-2 subunit vaccine candidate. Despite efforts to prevent genital herpes using gD-based subunit vaccines, to date, clinical trials using this antigen have failed. Therefore, using a small animal model, we sought to determine if a tetramerized truncated form of gD subunit vaccine, produced by recombinant baculovirus infected insect larvae, would elicit better protection against genital herpes than a monomeric gD-2 subunit vaccine. Three out of 5 mice immunized with the tetramerized antigen produced in a baculovirus expression vector system, survived a lethal challenge with a wild type HSV-2 strain (for more than 3 weeks after challenge). In contrast, all the mice (5) immunized with the truncated protein, produced by the same methodology, died within two weeks after challenge. These results suggest that multimerization (increasing the structural complexity) of the truncated gD antigen might be more likely protective than the monomer form. Also the use of an alternative cost-efficient eukaryotic expression system is described. Copyright © 2015. Published by Elsevier Inc.
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    • " , while antibody may provide some protection to neonates ( Brown et al . , 1991 ) , and recently antibody concentration was associated with preventing HSV - 1 genital disease and infection in gD2 vaccine immunized HSV - seronegative women , there is minimal evidence that antibody alone is effective against acquisition of HSV - 2 genital disease ( Belshe et al . , 2012 , 2013 ) , or virus reactivation and recurrent disease ( Spruance et al . , 1995 ) . This observation was nicely characterized in a study of patients with a history of frequent recurrences who had higher median serum antibody titers to HSV that were coincident with lower HSV - 2 - specific IFN - γ and IL - 2 production from PBMC ( Sprua"
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    ABSTRACT: Reactivation of latent herpes simplex virus 2 (HSV-2) infections can be characterized by episodic recurrent genital lesions and/or viral shedding. We hypothesize that infected (HSV-2 pos) asymptomatic individuals have acquired T cell responses to specific HSV-2 antigen(s) that may be an important factor in controlling their recurrent disease symptoms. Our proteomic screening technology, ATLAS™, was used to characterize the antigenic repertoire of T cell responses in infected (HSV-2 pos) and virus-exposed seronegative (HSV-2 neg) subjects. T cell responses, determined by IFN-γ secretion, were generated to gL, UL2, UL11, UL21, ICP4, ICP0, ICP47 and UL40 with greater magnitude and/or frequency among cohorts of exposed HSV-2 neg or asymptomatic HSV-2 pos individuals, compared to symptomatic recurrent HSV-2 pos subjects. T cell antigens recognized preferentially among individuals who are resistant to infection or who are infected and have mild or no clinical disease may provide new targets for the design of vaccines aimed at treating and/or preventing HSV-2 infection.
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    • "Unfortunately, however, the numerous attempts to develop anti-HSV vaccines have thus far proved unsuccessful [9]–[20]. Chiron and GlaxoSmithKline vaccine candidates based on recombinant HSV envelope glycoproteins have failed to show efficacy [21], [22]. This has prompted researchers to increase their efforts to define immune correlates of protection and new vaccination strategies able to induce protective immunity [8], [19], [20], [23]. "
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