Chlamydia Vaccine: Is Development Worth the High Cost?

At AAAAI 2017, Jared Ditkowsky, MD, of SUNY Downstate, spoke with MD Magazine about the connotations surrounding the development of a potential vaccine for Chlamydia trachomatis (C. trachomatis), the infection causing chlamydia - one of the most common bacterial sexually transmitted infections in the United States.

While there is no vaccine currently on the market, this is something people have been working towards for three or four decades now, and there've been some issues with vaccine development. Ditkowsky explained, "Part of the issue is that the pathology associated with chlamydia is largely based on the host immune response. When you're infected with chlamydia, your actual immune response causes a lot of the disease, so when you look to vaccinate against chlamydia, you need to vaccinate in a way your body can prevent infection, but doesn't respond in a way that it actually harms your body." Ditkowsky continued that researchers have been working on it a lot recently; they think they've discovered the specific immune response they're looking for to protect without causing harm. Now, they're looking for a way to elicit that appropriately in people. There're a lot of vaccines in development, at least one in phase 1 clinical trials.

In terms of whether developing a chlamydia vaccine is worth the projected cost, Ditkowsy said that it's a difficult question to answer as one person. Based on the research they've done and based on another study by the CDC, vaccination would be expensive - likely it would be more expensive than the cost of treating chlamydia. "But, what you get on the flip side is that you get a big reduction in chlamydia morbidity and a lot of the long-term sequelae associated with that - namely infertility, which is a big negative outcome associated with it," said Ditkowsky. He continued to explain that their model specifically estimates that over a 17-year period, if looking at a cohort of young women 9-26, a vaccination program might cost about $40 million more, but you cant avert thousands of cases of chlamydia, thousands of cases of pelvic inflammatory disease, and chlamydia-associated infertility. That's where the resource balance comes into play and the question becomes do you decide to spend the resources or not. In a resource-rich setting like the United States, it's likely worth it and the resources are available, but the question comes into play in more resource-poor settings where what you spend towards health care can be spent in one field or another field. "That's where the decision gets tricky," explained Ditkowsky.