Despite annual vaccinations, the U.S. faces a burden of influenza that results in thousands of deaths and hospitalizations each year. Studies have shown that in recent decades an average of 30,000 deaths among the elderly are attributable to influenza and that each year 36,000 Americans die of influenza and about 200,000 are hospitalized.

The flu season, which officially began Wednesday, continues to be a significant public health challenge.

Each year, 5 to 20% of the nation’s population come down with the flu, about 200,000 (of 15 to 16 million) people needing to be admitted to hospitals. Of these, approximately 36,000 die from influenza-related complications. Up to 90% of them are seniors. Last year, 86 children between the ages of 15 and 17 died of influenza.

For this year, the CDC is recommending that every child aged 6 months to 18 years be vaccinated, unless they have a serious egg allergy. Pregnant women who will be pregnant during the flu season-October through mid-May, persons over 50 years old, people with certain chronic medical conditions and residents of nursing homes or other chronic-care facilities are advised to get their flu shot. That means 30 million kids and a total of 86% of Americans are now supposed to get their flu shots this year.

Unlike last year when a surprise new influenza strain emerged, the CDC said that this year’s vaccine, which contains one influenza B strain and two influenza A strains, is a good match and should offer plenty of protection.

Influenza is a an infectious disease caused by a virus. Its symptoms include: fever, sore throat, muscle pains, headaches, weakness. The flu remains infectious for around one week within human body temperature. In the 20th century an influenza pandemic occurred three times killing tens of millions of people. The infections are mostly treatable in adults, but usually deadly in elderly people and very young children.