| Home
|
Flu vaccine evolves to keep up with
hardy bugs Posted 4-6-98 An unexpectedly strong showing of a flu strain that originated in Australia and took hold in California last winter has prompted officials to include it in the vaccine to be administered beginning in September. Last year’s vaccine gave only partial protection against type A/Sydney, which helped clog emergency rooms in Southern California in January. This fall’s vaccine will add type A/Sydney strain and a second new strain, type A/Beijing, to a type B/Beijing strain that was included in a slightly different form last year. Based on worldwide surveillance, these strains are expected to circulate in the1998-99 flu season, according to the Food and Drug Administration and the national Centers for Disease Control and Prevention (CDC). Influenza viruses mutate over time, and each year the vaccine is updated to include viruses that represent the most current variations. Currently, three different virus strains cause influenza epidemics; two type A strains and one type B, the CDC said. Nationally, about 140 physicians give weekly reports on the number and types of cases they see, and more than 50 U.S. laboratories that collaborate with the World Health Organization analyze specimens from October through mid-May. |
|