A mandatory stop on the way to college is the doctor’s office, where students tough out getting stuck by a few needles, vaccines to protect against some serious and sometimes deadly hazards that come with being in close quarters with hundreds of other students. Tetanus, Meningococcal and Hepatitis B — scientists are developing another injection to add to the list, one that would protect students from a risk of sexual activity that goes on in those close quarters: a chlamydia vaccine.
Scientists at Harvard and Queensland University of Technology are working with koalas, mice and guinea pigs to develop a vaccine for the most prevalent sexually transmitted bacterial infection along the Charles.
A VACCINE FOR/ FROM DOWN UNDER…
According to the 2007 Boston Public Health Commission, there was a 48 percent increase in cases of chlamydia among Boston residents from 1999 to 2005, rising from 432.8 cases per 100,000 people to nearly 642. And 15- to 19-year-olds reported 2,583 new cases per 100,000 people.
“It’s an enormous public health problem,” said Harvard professor Michael Starnbach, who is working with Queensland University of Technology professor Peter Timms to develop a vaccine. “It’s an organism that’s able to affect people and to persist in the human population. . . . It lives intimately with its host. It doesn’t cause a great deal of overt symptoms. People are able to carry the organism and spread the organism without dying and often without seeking treatment.”
For 15- to 29-year-olds, infection incidences are increasing by 15 to 20 percent per year, and actual rates may be higher because many cases of chlamydia lack symptoms, Timms said in an email.
But the two scientists have spent the past five weeks injecting mice in Brisbane, Australia, with strains of the disease in hopes of moving onto human testing for a vaccine in three to five years.
“We’re studying how the immune system recognizes the chlamydia infection and how the organism triggers the immune response,” Starnbach said. “We have developed engineered mice to track the immune response to the organism during infection. The goal with this collaboration is to better understand how the immune system reacts to these infections.”
“We hope to use the techniques we have developed to study the human strains and generate tools to study infection in the mouse models used in Australia,” Starnbach said. “We’re anxious to understand what kinds of responses are generated in those animals.”
“We can’t do experiments directly on humans, so by understanding how chlamydia infects these other animals [which include, he said, guinea pigs and koalas], we may learn more about human infection,” he continued.
Infecting these animals with chlamydia allows Starnbach and Timms to monitor the potential of a vaccine and to test specific formulations.
“I really appreciate the value of what they are doing in Australia, including the use of koalas as a model system,” Starnbach said. “Koalas can be brought in to zoos from regions where there is no chlamydia and mixed with animals that have chlamydia. The chlamydia will then spread from infected animals to the uninfected animals. One can’t watch and monitor that in a human population. So [Timms] and his team can vaccinate the uninfected animals before they are exposed to infected animals and see whether the vaccines can protect against spread.”
THIS WON’T HURT — AS MUCH
Sticking a band-aid on one more poke would likely be an attractive alternative for anyone who has suffered the symptoms of chlamydia — though it can also come without any symptoms at all.
“Chlamydia can be asymptomatic,” said Dr. David McBride, Boston University director of Student Health Services in an email. “For women, [symptoms can be] vaginal discharge, pelvic pain. For men, penile discharge, burning with urination.”
Government officials encourage screening for chlamydia for all sexually active women 24 and younger, and for older, non-pregnant women who are at any increased risk.
And for a disease which, like many STDs, can be prevented only by condoms or dental dams and abstinence, chlamydia currently makes its mark on the younger set in Boston.
“I’m sure it has something to do with [the high rate of infection],” McBride said. “In particular, I think that college students often ignore the risks of having sex without a condom.”
Currently, doctors can only treat the disease after the fact. “At SHS, we test via cervical specimen or via urine. If positive, we offer treatment with antibiotics via a prescription,” McBride said.
CHLAMYDIA AT LARGE
Although treatment for chlamydia — which costs the U.S. about $2 billion per year – exists in the form of antibiotics, paying for a vaccine would be more efficient, Timms said.
“The costs of a vaccine compared to the costs of treating the adverse disease outcomes will be 50 to one in favour [sic] of a vaccine,” Timms said.
“It’s hard to ignore the fact that it’s the leading cause of sexually transmitted diseases,” Starnbach said. “We are seeing incident rates in adolescent girls that are absolutely a crisis. As they mature into age of reproduction, they will face major problems such as infertility. And in the developing world, the organism causes blindness called trachoma.”
Both Starnbach and Timms have been researching chlamydia for over 10 years. Funding provided by the Harvard Club of Australia Foundation allowed Starnbach to travel to Australia last month.
The scientists aren’t the first to research a chlamydia vaccine, “but it is a very difficult problem to solve; like a HIV vaccine in some ways,” Timms said.
The possibility of a chlamydia vaccine has been well-received by the public in the United States and abroad.
“Everyone in Australia [and the U.S. press] has been very positive, to date at least,” Timms said.
“[Timms] and I had thought about doing this project, but the Foundation’s funding made it possible,” Starnbach said. “The foundation is a group of individuals that cared enough to seed this project that we anticipate will continue for many years.”
LOCAL REMEDIES
Student organizations such as Peer Health Exchange work to inform high school students in the Boston area about STDs such as chlamydia.
“We have a workshop on STDs that goes through common symptoms,” said Jamie Sharp, Peer Health Exchange member and College of Arts and Sciences junior. “For chlamydia, we describe its transmission, prevalence and health effects. Without that information, you can’t make informed decisions.”
Peer Health Exchange teaches ninth graders about STDs and includes recommendations about HPV vaccinations. Sharp said that it is likely to include similar information when a chlamydia vaccine is ready.
“I guess it’s difficult because we’re working with teens,” Sharp said. “There’s definitely the notion of invincibility, the notion that a vaccine — some could argue — gives you a free ticket.”
“When it comes down to it, it’s up to the individual,” she added.
SHS’s McBride said a chlamydia vaccine would be unlikely to encourage promiscuity. “Of course, if [a vaccine] worked, it would be great,” he said. “There are still other risks to unprotected sex… HIV, HPV, gonorrhea, herpes, crabs, scabies, molluscum contagiosum, lymphogranuloma venereum, syphilis. Then for women, there’s pregnancy. Chlamydia is by far not the only risk of unprotected sex.”
“I definitely think [a vaccine] would be beneficial,” said Kelsey Johnson, also a member of Peer Health Exchange and a CAS sophomore. “I don’t think because you can get vaccinated, you’re going to have sex more often. If people want to have sex, they’re going to.”