The third COVID-19 vaccine authorized for use in the U.S. requires one shot instead of two, and works a slightly different way from the others. Here's what we know about its safety and effectiveness.
Pfizer's CEO sold $5.6 million worth of stock on Monday. The company says the stock sale was made as part of a preset plan. But NPR found irregularities about when the CEO entered into that plan.
Pfizer's COVID-19 vaccine is the first to have data showing that it exceeded the minimum effectiveness threshold set by the Food and Drug Administration for emergency use.
Several COVID-19 vaccine candidates are being tested now. But why does it take 30,000 volunteers to know if one is safe and effective? And what does it mean to say a vaccine candidate is working?
The Food and Drug Administration has approved a drug that thwarts some enzymes breast cancer cells use to evade treatment with estrogen-blocking drugs.
