The symptoms are similar for children, but they can also get pain in their ear and appear less active. It's more effective to get the vaccine before the start of the flu season December to March. At-risk groups eligible for the flu vaccine include people with a chronic neurological disease; respiratory, heart, kidney or liver disease; diabetes and the overs.
Pregnant women have a much higher risk of serious illness if they get the flu, with possible complications including pneumonia, septic shock and encephalitis inflammation of the brain.
Jump directly to the content. While most cases of pandemic H1N1 were mild, globally it is estimated that the pandemic caused between — deaths in the first year alone. Children and young adults were disproportionately affected in comparison to seasonal influenza, which causes severe disease mainly in the elderly, persons with chronic conditions and pregnant women.
Three influenza pandemics occurred at intervals of several decades during the 20th century, the most severe of which was the so-called "Spanish Flu" caused by an A H1N1 virus , estimated to have caused 20—50 million deaths in — Milder pandemics occurred subsequently in — the "Asian Flu" caused by an A H2N2 virus and in the "Hong Kong Flu" caused by an A H3N2 virus , which were estimated to have caused 1—4 million deaths each.
Although influenza A H3N2 viruses predominated in the United States during the season, high levels of influenza A H1N1 and influenza B viruses circulated as well. The relative proportion of each virus type and subtype varied by geographic region and week during the influenza season.
Overall, however, influenza A H3N2 viruses were most commonly reported during the flu season in the United States. Influenza A viruses are subtyped in public health laboratories, such as state department of health laboratories and CDC Influenza Division laboratories.
The effectiveness of the seasonal flu vaccine can vary from year to year and among different age and risk groups. In general, the highest vaccine effectiveness is seen among young healthy adults and older children. Lower vaccine effectiveness is reported for young children e. Vaccine effectiveness also depends on the degree to which influenza vaccine viruses are well matched to circulating influenza viruses. Lower effectiveness is expected in years when the match between circulating and vaccine viruses are suboptimal.
In healthy adults younger than 65 years of age, the flu vaccine can also prevent lost work days, and keep you from having to see the doctor or using unnecessary antibiotics.
Every year CDC carries out evaluations and collaborates with outside partners to assess the effectiveness of seasonal flu vaccines.
CDC is currently conducting annual vaccine effectiveness studies among persons of all age groups recommended for annual vaccination i. In addition, CDC conducts special studies targeted at answering more specific questions, such as the effectiveness of inactivated vaccine in preventing laboratory-confirmed influenza hospitalizations among older U. Almost all of the 2, influenza viruses submitted to CDC for antigenic characterization were found to be similar to the components of the influenza vaccine.
Of the viruses tested, Flu viruses are constantly changing called antigenic drift — they often change from one season to the next or they can even change within the course of one flu season. Influenza Flu. Section Navigation. Facebook Twitter LinkedIn Syndicate.
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