vaccines

Rotavirus explained: how a wheel-shaped virus causes severe infant diarrhea, how its NSP4 toxin works, and how oral vaccines changed the toll.

How yellow fever virus moves from monkeys to cities, why it attacks the liver, and how the 17D vaccine, a single dose, gives lifelong protection.

From smallpox to COVID-19, vaccines are humanity's most powerful medical technology. Here's how we discovered them.

Vaccines taught the immune system to beat smallpox, polio, and measles, and a 2024 Lancet study estimated they averted 154 million deaths in 50 years. Yet hesitancy persists. Here is the immunology, the safety evidence, and the psychology behind refusal.

What decides how fast a disease spreads, how many people it kills, and which defenses work? The epidemiology of pandemics, from reproduction numbers to vaccines, with the 1918 flu and COVID-19 as test cases.

Vaccine safety is one of the most studied topics in medicine. Here's a clear, science-based examination of what the evidence really shows.