Chlamydia researchers just solved a 50-year-old mystery, handing us the keys to a potential vaccine.
Chlamydia researchers may have solved a 50-year-old scientific mystery. And in doing so, they designed what looks like the most promising candidate for a chlamydia vaccine that we’ve seen in a long time.
Chlamydia is the most widespread bacterial sexually transmitted infection in the world. In the US, over 1 million chlamydial infections were reported to CDC in 2013. Most people clear the infection on their own, but in some cases, it can cause infertility in women, ectopic pregnancies, pneumonia, and pelvic inflammatory disease. And when the infection occurs in the eyes, chlamydia can lead to blindness. In fact, it’s the most common cause of preventable blindness. That’s why a vaccine for this particular STI is so dearly needed. Most people don’t seek treatment because they don’t show any visible signs of infection — and then they pass it on.
CHLAMYDIA VACCINE STUDIES IN THE 1960S DIDN’T GO VERY WELL
Unfortunately, research on chlamydia vaccines hasn’t gone all that well, historically. In the 1960s, scientists designed a number of chlamydia vaccines that they then tested on humans — including very young children — in developing countries. But the vaccine didn’t always have the desired effect; in some cases, people who were vaccinated became more likely to develop chlamydia than people who weren’t. The result was puzzling, especially given that other studies showed that people who had previously been infected with chlamydia tended to show an attenuated response to subsequent infections. Chlamydia vaccine research in humans became less popular after that period, and researchers never figured out why their vaccines had this less than desirable effect.