Curable bacterial sexually transmitted infections (STIs), including Chlamydia trachomatis, Neisseria gonorrhoeae, Treponema pallidum, Haemophilus ducreyi, and Mycoplasma genitalium, remain serious public health challenges driven by increasing infection rates and asymptomatic cases, reinfections, and growing antimicrobial resistance. Although the STIs caused by these microorganisms are treatable with antibiotics, the rising number of infections, antibiotic resistance (currently and in the recent past), and lack of fully protective vaccines highlight an urgent need for effective preventive solutions. This review presents a comprehensive evaluation of the current status and scenario of vaccine development against these bacterial STI pathogens. For Chlamydia trachomatis, protein subunit vaccines targeting Major Outer Membrane Proteins have shown immunogenicity in early clinical trials. Neisseria gonorrhoeae, with its high antigenic variability and immune evasion, poses a significant challenge to vaccine design, but cross-protection observed with meningococcal Outer Membrane Vesicle vaccines is encouraging. Its culturability and immune evasion mechanisms limit research on Treponema pallidum, but bioinformatic strategies have identified novel multi-epitope vaccine candidates. Vaccine development against Haemophilus ducreyi and Mycoplasma genitalium is just at the beginning. Rising antimicrobial resistance, especially in Neisseria gonorrhoeae and Mycoplasma genitalium, underscores the urgency of vaccine-based interventions. The integration of in silico methods such as reverse vaccinology, structural biology, and immunoinformatics is accelerating the identification and discovery of vaccine candidates. Still, significant challenges persist, including antigen variability, immune escape, and limited funding. A coordinated global strategy combining vaccine development, antimicrobial resistance surveillance, and unbiased distribution is essential to reduce the burden of bacterial STIs and secure long-term disease control.
Gomes et al. (Wed,) studied this question.