Have you had your annual flu vaccine? If so, there’s a good chance that you still became ill. That’s because preliminary data suggests the Influenza shot is only about 30% effective against H3N2 and closer to 40% against all viruses, mentioned Daniel Jernigan, Director of the CDC’s Influenza Division.
One of the biggest factors in the transmission of Influenza this month is children going back to school after the holidays, Dr. Jernigan said. Viruses spread easily among schoolchildren, who spend their days in close quarters and then carry the viruses home.
The flu is most contagious during the early phase of infection. Specifically, when they have a runny nose and bad cough,” said Paul Sax, an infectious disease specialist at Brigham and Women’s Hospital in Boston. “That’s a very important time for people to stay out of work and school.”
MAP: CDC Influenza Rate