It's the first vaccine for the sexually transmitted human papillomavirus, which causes genital warts and cervical cancer. But girls vaccinated with Gardasil since 2006 have experienced some serious side effects, including seizures and fainting, and 27 teens died after receiving the shot. An ongoing study is investigating whether these events were caused by the vaccine; health officials say the shot is safe.
In good times and bad, science doesn't sleep, and every year brings breakthroughs, setbacks, reasons for worry and reasons for joy. TIME's annual alphabetical roundup of a sampling of those stories gives you an overview of the year behind and a hint of what might be in the one ahead.