The answer given about vaccines targeting a specific part of a bacterium's lifecycle isn't correct. That's how antibiotics work, not how vaccines work. Vaccines work by causing your body's own immune system to develop antibodies. read more
HIV vaccines don't work because the virus targets the immune system. You can make antibodies to HIV, but it appears to be able to evade the immune cells that would recognize those antibodies. Some viruses mutate very rapidly, changing their outer protein structure often. read more
That is, it can’t “hide” in an animal population and re-emerge to infect humans, while some diseases can do just that (yellow fever, for example, can infect some primates; if a mosquito then bites an infected primate, it can transmit the virus back to humans). read more
Antibiotics, our most potent weapon against bacterial infections, are losing their power because the bacteria are becoming resistant. In this course, we'll explore the major themes of infectious diseases dynamics. After we’ve covered the basics, we'll be looking at the dynamics of the flu, and why we're worried about flu pandemics. read more