Following a rise in sexually transmitted infection diagnoses in recent years, NIAID is awarding grants for research into syphilis, gonorrhea, and chlamydia vaccine candidates.
With an increase in the rate of reported sexually transmitted infections (STIs) in the United States, the National Institutes of Health’s (NIH) National Institute of Allergy and Infectious Diseases (NIAID) has announced a program of more than $41 million dollars to fund research into vaccines for syphilis, gonorrhea, and chlamydia.
The recent NIAID announcement details the establishment of 4 multi-institutional cooperative research centers (CRCs), which over the next 5 years are each set to develop at least 1 vaccine candidate to prevent infections from syphilis, gonorrhea, and chlamydia. In an interview with Contagion®, NIAID Director Anthony S. Fauci, MD, explained that the growing rate of STIs in the United States coupled with scientific advances have made now the appropriate time for such much-needed vaccines, though much remains to be understood about the rise in STIs.
“It’s multifactorial. Certainly we are better at diagnosis as well as surveillance, so the real increase that we’re seeing is probably that we’re picking up more cases, but there are probably some other factors,” explained Fauci, noting that the increase in STIs may be linked to the opioid epidemic as well as an increase in unprotected sex, suboptimal sexual health education, and the use of PrEP to prevent HIV resulting in more sex without condoms.
Much as cervical cancer rates have declined following the introduction of the human papillomavirus vaccine, health officials hope that the development of additional STI vaccines will have a cascade of public health benefits. The number of reported syphilis cases in the United States rose by 76% from 2013 to 2017, and today the disease is the second leading cause of miscarriage and stillbirth worldwide. In the new program, a CRC based at the University of Connecticut (UCONN) School of Medicine will receive $11 million to develop a syphilis vaccine candidate targeting surface-exposed proteins within the outer membrane of Treponema pallidum, the bacterium that causes syphilis.
In addition, 2 centers based at Georgia State University and the Uniformed Services University of Health Sciences will receive nearly $20 million combined to investigate gonorrhea vaccine candidates. Gonorrhea diagnoses in the United States increased by 67% from 2013 to 2017, rising to more than half a million cases, a startling statistic considering the now-high antibacterial resistance rates among Neisseria gonorrhoeae bacteria. Georgia State’s projects will focus on strategies of starving gonococcal bacteria by interfering with bacterial nutrient transport. The Uniformed Services University of Health Sciences will conduct 4 projects as part of the Gonorrhea Vaccine Cooperative Research Center, focused on immune signals and evidence that candidate gonorrhea vaccine has induced immunity.
“Gonorrhea is really quite common,” said Fauci. “We have a problem with gonorrhea, particularly with the issue of drug resistance that we’re not necessarily seeing with syphilis and chlamydia. One of the real problems in that even though in the United States we still can use ceftriaxone, the fact is that there is the problem of the emergence of an even greater degree resistance to gonorrhea.”
A center based at the University of North Carolina at Chapel Hill School of Medicine will receive $10.7 million toward chlamydia vaccine research to prevent infections caused by Chlamydia trachomatis, the most common sexually transmitted disease worldwide. According to the US Centers for Disease Control and Prevention (CDC), the rate of reported chlamydial infections has more than doubled, increasing from 251.4 cases per 100,000 population in 2000 to 528.8 cases per 100,000 population in 2017. Of the 1.7 million cases of chlamydia diagnosed in the US in 2017, 45% were in women aged 15 to 24 years. The chlamydia vaccine candidate research will include studying women’s immune system responses to chlamydia infection to help investigators find vaccine candidates capable eliciting robust T cell responses.