Biological feasibility and importance of a gonorrhea vaccine for global public health

Abstract

There is a growing public health interest in controlling sexually transmitted infections (STIs) through vaccination due to increasing recognition of the global disease burden of STIs and the role of STIs in women's reproductive health, adverse pregnancy outcomes, and the health and well-being of neonates. Neisseria gonorrhoeae has historically challenged vaccine development through the expression of phase and antigenically variable surface molecules and its capacity to cause repeated infections without inducing protective immunity. An estimated 78 million new N. gonorrhoeae infections occur annually and the greatest disease burden is carried by low- and middle-income countries (LMIC). Current control measures are clearly inadequate and threatened by the rapid emergence of antibiotic resistance. The gonococcus now holds the status of "super-bug" as there is currently no single reliable monotherapy for empirical treatment of gonorrhea. The problem of antibiotic resistance has elevated treatment costs and necessitated the establishment of large surveillance programs to track the spread of resistant strains. Here we review the need for a gonorrhea vaccine with respect to global disease burden and related socioeconomic and treatment costs, with an emphasis on the impact of gonorrhea on women and newborns. We also highlight the challenge of estimating the impact of a gonorrhea vaccine due to the need for more data on the burden of gonococcal pelvic inflammatory disease and related sequelae and of gonorrhea-associated adverse pregnancy outcomes and the problem of empirical diagnosis and treatment of STIs in LMIC. There is also a lack of clinical and basic science research in the area of gonococcal/chlamydia coinfection, which occurs in a high percentage of individuals with gonorrhea and should be considered when testing the efficacy of gonorrhea vaccines. Finally, we review recent research that suggests a gonorrhea vaccine is feasible and discuss challenges and research gaps in gonorrhea vaccine development.

Genetic Similarity of Gonococcal Homologs to Meningococcal Outer Membrane Proteins of Serogroup B Vaccine

“…OMP, outer membrane protein; ϩ, predicted as OMP by at least 2 tools; -, not predicted as OMP by any of the tools; ϩ/-, predicted as OMP by 1 tool; NA, not applicable due to the absence of an ORF. (9,12,13,41). The remaining 34 OMPs, including the MenB-4C vaccine antigens FHbp and NhbA, had not been previously identified in NZ98/254 OMVs.…”

“…Gonorrhea facilitates human immunodeficiency virus (HIV) transmission through the stimulation of antiapoptotic proteins essential for the HIV life cycle (11). The emergence of N. gonorrhoeae strains that are resistant to nearly all classes of antibiotics available for treatment and the lack of an effective gonococcal vaccine (9,10,12,13) underscore the urgent need for new prevention and control measures.…”

Liposomes used as a vaccine adjuvant-delivery system: From basics to clinical immunization

“…In prospect, liposomes may be further formulated into an advanced VADS that is suitable for developing the efficacious vaccines to combat many tedious pathogens, especially, some most challenging ones, such as HIV, HCV, HSV, and even the emerging super bugs [164,165]. For this, in future, liposomes may be developed to play roles of a versatile VADS that can mimic the way whereby the Ags are maintained and exposed to APCs by a pathogen during a natural infection to trigger strong immunoresponses [166].…”

Bacterial sexually transmitted infections

“…Given the current trends in antibiotic resistance, new therapeutic approaches are required. Apart from testing new classes of antibiotics in the treatment of gonorrhea , the feasibility of a new vaccine against N. gonorrhoeae has also been investigated, using an existing vaccine against Neisseria meningitidis .…”