This post has been updated.

This flu season could be a bad one, and Health and Human Services Secretary Tom Price got his flu shot Thursday and urged Americans to follow his example and get vaccinated.

But after getting jabbed, Price, who is under fire for his flights on government-funded private jets, left before a scheduled question-and-answer session. He rolled down his sleeve and hurried out of the room at the National Press Club even before putting his suit jacket back on.

Reporters followed him out, shouting questions.

“We're going to work through this, and I think we've still got the confidence of the president,” he told reporters. He declined to comment about whether his taxpayer-funded use of charter jets was appropriate, saying he is waiting for the outcome of an HHS inspector general review.

Several hours later, Price issued a statement that he would reimburse taxpayers and would take "no more private charter flights." He said he regretted the concerns his travel has raised.

In his remarks at the annual flu awareness event, Price noted that vaccination coverage has plateaued and that fewer than half of the U.S. population was vaccinated last season. Even though overall flu vaccination coverage ticked up slightly last season, the hospitalization rate nearly doubled from the previous season and was higher across all age groups than in seven of the eight previous seasons.

Just a 5 percentage point uptake in vaccination coverage could have prevented nearly half a million cases of flu last season, Price said. “We’ve got a lot of room for improvement,” he stressed.

The Centers for Disease Control and Prevention recommends that everyone 6 months and older get an injectable flu vaccine before the end of October, if possible. It takes about two weeks for the body to produce a full immune response. 

Price, who has not always given the most full-throated public defense of vaccines, hailed them on Thursday. “Vaccines are among the greatest public health achievements of modern times,” he said. “But they’re only as useful as we as a society make them.”

Next year is the 100th anniversary of the world influenza pandemic known as the Spanish flu — an outbreak that infected one-third of the world’s population and killed at least 50 million people, including 675,000 Americans. An influenza pandemic poses one of the world’s greatest infectious disease challenges, Price said. 

The United States is preparing for the eventuality that another pandemic will happen, he said. "Our annual efforts to protect against seasonal flu are the foundation for our response to a pandemic."

Experts say the upcoming flu season could be severe, based on surveillance in the Southern Hemisphere, often a clue for what to expect in the United States. More than 2.5 times the number of laboratory-confirmed cases of influenza have been reported this year compared with the same period last year. 

Flu virus infections began increasing earlier than usual in Australia and hit historic highs in some states, according to government data. The most troubling news is that influenza A (H3N2) viruses were most common in Australia. Seasons where H3N2 is dominant typically result in the most complications, especially for the very young and the old, experts say. Vaccines are less effective against H3N2.

“It’s the fiercest one,” said William Schaffner, an infectious-diseases expert at Vanderbilt University and medical director of the National Foundation for Infectious Diseases, which sponsors the annual event at the press club.

During the summer in the United States, similar H3N2 viruses were the most common flu viruses to circulate at low levels. 

Every year, new flu vaccines are designed based on detailed characterization of the influenza viruses circulating in the previous season. Flu viruses that are transmitted between humans mutate easily as they pass from person to person. 

For the upcoming season, manufacturers have estimated that up to 163 million doses of injectable flu vaccine will be available in the United States. More than 73 million doses already have been delivered. The vaccine has been updated and is designed to protect against the viruses that research suggests will be most common during the 2017-2018 season, including the H3N2 virus.

Officials said they don’t really know why vaccination coverage has remained stagnant, though Schaffner said health-care providers need to be more forceful.

The vaccine is not perfect, but it typically reduces the risk of flu by between 40 and 60 percent among the overall population when well-matched to most circulating viruses. Those numbers don't take into account the partial protection the vaccine offered for “those who didn’t have to go to the hospital and who didn’t die from influenza,” he said.

Flu shots are particularly important for people older than 65, Schaffner said. Even when older people recover from a bout of flu, “they may not be as strong as they were before,” he said.

Vaccination coverage has also lagged among those working in health care, particularly in long-term care facilities.

Patsy Stinchfield, senior director of infection control and prevention at Children's Minnesota, said her hospital tries to make vaccinations as accessible as possible. But just as in the general population, some health-care professionals have a fear of needles, she acknowledged.

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