"The H3N2 strain from one year to the next is not expected to be the same because we understand that the flu virus itself and the various strains continue to mutate and change over time".
Howard Njoo, deputy chief public health officer for the Public Health Agency of Canada, says even when the flu vaccine is less effective it is still better than no protection at all.
Furthermore, the CDC said it was concerned by early-season coverage data that showed vaccination among pregnant women to be low, leaving them unprotected from flu this season.
"It's very important for those that are already vaccinated, to encourage, hopefully, family members and others to get vaccinated as well". That's the virus' way of evading our immune systems. A positivity rate of more than 10 percent indicates that flu transmission is occurring in the community, and the peril is likely to persist for months. According to The Washington Post, more than 6,000 people across the nation had tested positive for the flu as of last week - more than twice as many as were reported at the same time previous year.
A nurse administers a drip to flu patients at a hospital in Beijing on December 12, 2005, as the winter malady is causing hospitals to be packed with flu patients.
Still, there are some people who should not get the flu shot.
Despite the early concerns about the 2017 flu vaccine based on its effectiveness in Australia, Dr. Patricia Quinlisk, Iowa's state medical director and epidemiologist was more upbeat.
"We do see a predominance of the H3N2 virus that was common last season", Flannery said.
"What's predominant now might not be predominant a month from now; and so what's in the vaccine versus what's the predominant strain in the community is going to really determine how effective the vaccine is", Dr. Wallace said. A version of the vaccine produced without eggs is available this year for people with egg allergies.
Tens of thousands of people die from the flu each year in the USA, the CDC reports, and getting vaccinated saves lives, even if the effectiveness of the vaccine varies from year to year, Baumbach said.
Almost 100 people have been hospitalized this past week in Dallas County with flu-related illnesses. They're also emphasizing the need for what would be the Holy Grail of flu vaccination - a universal shot that wouldn't have to be adjusted and injected each season.
"If you are sick, it's best to get the vaccine after you recover", says Blum, "but please don't wait until it's too late in the season". Having a global estimate is useful, she said, and the country-specific estimates in the new study are valuable, because they can be used by country decision-makers.
Bottom line, don't expose yourself and stay away from people who are coughing, sneezing or even look sick.
If you come down with symptoms matching the flu virus, the CDC says you should stay home and avoid contact with others for at least 24 hours or until your fever subsides.