Although this flu season is off to a slow start, U.S. health officials are urging everyone to get vaccinated now.

Why? Last year was one of the worst flu seasons on record, yet fewer Americans got a flu shot than in years past. In fact, less than four in 10 adults were protected against flu and its complications last winter, according to the U.S. Centers for Disease Control and Prevention.

Now is the perfect time to get vaccinated … it gives your body enough time to respond to the vaccine and mount a good immune response so you’re ready for the flu season. October-November is the best time to get a flu shot. The vaccine reduces your odds of influenza, and if you get the flu it makes it much milder.  The vaccine is particularly important for women who have children too young to get a flu shot, people aged 65 and older, and anyone with chronic heart or lung disease.

About 132 million doses of the vaccine have been distributed so far, and about 168 million will be available through the 2018-2019 flu season, according to the CDC.  Several viruses are circulating, including influenza A strains H1N1 and H3N2, and two influenza B viruses.  The CDC estimates that the flu sickened 49 million, hospitalized nearly 1 million and killed 79,000.  Nearly 12 million children came down with the flu, and 48,000 were hospitalized, CDC statistics show. Of those, 183 died. Among those aged 18 to 64, 30 million were sickened and 10,300 died.

In all, 70 percent of those hospitalized for flu were aged 65 and older, as were 90 percent of those who died, according to the CDC.  For H1N1, the vaccine is up to 60 percent effective, as it is for the influenza B viruses. For the H3N2 virus it’s less effective, since H3 viruses can change to fool the body’s immune system. This year, the H3N2 virus component of the vaccine has been tweaked to better match the circulating strain.