How bad will this year’s flu be? Should your kids get the flu mist? How long will the vaccine last?

UW Health doctors answer all your flu questions

September 12, 2018 12:37 PM

Christina Lorey,

Posted: September 12, 2018 12:37 PM

Updated: August 31, 2021 12:26 PM

by Christina Lorey

MADISON, Wis. — The flu usually picks up in October and November and peaks during the winter months, but experts say now is the time to get your flu shot.

Every year, as many as 20 percent of Americans get the flu and thousands die from flu-related illnesses. Ahead of this year’s outbreak, doctors from UW Health are predicting just how bad this year’s flu season might be.

Who should get the flu vaccine, and when?

Doctors at UW Health say everyone 6 months old or older should get a flu shot as soon as possible, especially before the end of October.

How long does it take for the vaccine’s effects to kick in?

It takes about two weeks after getting the vaccine for the protective effects to begin.

This year’s vaccine has been adjusted for the upcoming flu season to target the strains expected to circulate this year. The CDC says it can’t predict whether this season’s vaccine will be a particularly good match for the viruses circulating this year, but experts say some protection is better than none.

How bad will flu season be this year?

Unfortunately, it’s impossible to predict how bad this year’s flu season will be. “You know, I have a magic eight ball here on my desk to try and help,” joked Dr. James Conway, UW Health infectious disease specialist. “And it always tells me ask again later.”

Doctors say they have to make a guess in January and February, based on observations of what’s circulating in the southern hemisphere, of what is going to show up nine or ten months later. They say the only predictable thing about the flu is that it’s unpredictable.

Should my kids get the nasal spray or the shot?

New this year: the nasal spray vaccine has been reformulated and is now, once again, offered and recommended by the CDC.

The American Academy of Pediatrics says there’s not enough information yet about it, but could be used in non-pregnant women and people between the ages of 2 and 49.

“They had originally said it should be the vaccine of last resort, and I think they’ve backed away from that a little bit and said it’s certainly a viable alternative, but there’s a lot more data for the injectable vaccine since we’ve been using it consistently now for decades,” said Dr. Conway.

When does flu season start and end?

Flu activity tends to pick up in October and November, and it usually peaks between December and February. Cases of the flu can last through the spring.

If I get my flu shot now, will it still protect me at the end of flu season?

Despite some misleading articles out there, if you get the flu shot early in the season, your protection will not run out before flu season ends. “The articles that suggest there are breakthrough cases late in the season usually are related to the fact the flu virus has changed throughout the season and new ones emerge,” said Dr. Conway. “So when people get diseases later in the season, it’s usually not that the vaccine is failing: it’s that the viruses are changing.”

How many Americans actually get the flu?

Each year on average, between 5 and 20 percent of the U.S. population gets the flu, tens of thousands are hospitalized, and thousands die from flu-related illnesses. The CDC estimates it costs upward of $10 billion in medical expenses and an additional $16 billion in lost earnings.

People who pass on getting flu shots may have second thoughts about skipping them this year. About 1 in 5 people who didn’t get the vaccine last season reported they’re more likely to get the flu shot this time around because the last season was so severe, according to a Harris Poll released in July.