My enemy’s enemy is my… enemy?

Like a kind of Russian doll infection, a prolific human parasite—responsible for almost 250 million infections annually—can itself harbour a parasite, a virus. You might reasonably feel a sense of something akin to schadenfreude; glad it’s getting a dose of its own medicine, so to speak… But you may be too hasty. The very presence of this virus—though it doesn’t infect human cells—in its parasite host could be making infections worse, or even stymying our attempts at  relieving the infection. The parasite in question, with around 3.7 million people infected in the US alone, is the most common protozoan infection in the industrialised world: Trichomonas vaginalis (TrV). It infects the human genitourinary tract of both men and women causing Trichomoniasis; in fact, it can only live in the human genitourinary tract (an ‘obligate human parasite’). Women are more likely to experience symptoms than men, and while generally mild,  it can be bad. Its ...(Read More)

The “Dirty Little Secret”* About Vaccines

Note: This originally appeared on the SciBox section of the Oxford SciBar. Check out the site, there’s a host of podcasts of talks and other articles there.   In some ways, the immune system’s like a brain: it can learn, it can adapt and, so it’s ready for the next time, it can remember. This is, perhaps, its single most important feature. The immune system has the chance to learn a unique signature on the surface of an invader every time we’re infected by something, be it virus, bacteria or even a parasite. Once it learns these signatures the body produces antibodies or ’killer cells’ to fight it. When the infection has been defeated, special cells – B-cells – remember it, for as long as a life time. If the invader returns it won’t have such an easy time: the immune system will be ready. Like most things that learn, the ...(Read More)