The threat of avian influenza has revived efforts to develop "universal" flu vaccines that protect against all human influenza strains. Although that goal remains elusive, vaccines that protect against seasonal flu variants could be closer Modern medicine's main weapon against the influenza virus is woefully unsophisticated. Each year, companies have to make a new batch of flu vaccine because unlike, say, polio or chickenpox, flu strains change every year. The vaccine is grown in eggs, a process that takes up to 9 months, and people have to be vaccinated annually, which many don't bother to do. More troubling, if a pandemic strain of influenza came along, the virus could kill millions of people in the time it would take to prepare a matching vaccine.
展开▼
