NewsLocal News


A doctor explains why you feel terrible after a flu shot

And why it's still important to get it
Posted at 5:03 PM, Nov 12, 2019
and last updated 2019-11-12 18:10:05-05

CLEVELAND — In a Facebook post that's been shared more than 200 times, a woman from Lake County said her son had a severe allergic reaction after getting his flu shot.

In her post, which she shared with News 5, Josie Bela said her children get flu shots every year. But this year, her son started sneezing and coughing not long after getting his shot. Bela said he also developed hives, and his lips and eyelids swelled. She said her son was treated with an EpiPen and steroids before returning to normal.

Reactions to the flu shot and what's in the shot itself

While doctors don't see many issues with the flu shot, reactions can still happen, according to Dr. Christine Alexander, chair of family medicine at MetroHealth.

"We engineer the flu shot," Alexander said. "We’re not giving a live virus. We are engineering something that looks exactly like the live virus, so it leads our body into developing the immunity to that particular virus."

Alexander said the flu shot changes a little each year, as the Centers for Disease Control and Prevention track what might be the dominant virus for the upcoming flu season and try to match the flu shot accordingly. However, some ingredients in the shot remain the same each year.

"When you receive the flu vaccine, you want it to be absorbed and you want it to be able to be activated by the body so it can do its work," Alexander said. "So there are products that allow that to happen. There’s also preservatives because the flu is a year-round virus. We do give flu vaccines until we run out of all of them. That usually lasts pretty handily through the flu season."

In addition to the preservatives, Alexander said, there are small amounts of antibiotics in the flu shot to prevent bacterial infections from growing in there. Gelatin is another ingredient, as are ingredients made from eggs.

"The biggest thing we worry about are severe egg allergies, because of the way the flu shot is made," Alexander said. "We engineer the flu shot. We’re not giving a live virus, we are engineering something that looks exactly like the live virus, so it leads our body into developing the immunity to that particular virus. So we worry about egg allergies, but those are pretty severe egg allergies. So if you have an egg allergy but you can eat something that’s made in a commercial bakery, you’re safe to get the flu shot."

If someone is concerned about a reaction, Alexander said, it's a good idea to get the shot and be monitored in your provider's office, "just to see if there are any allergic reactions that develop that can then be treated right in the moment."

Not feeling well after a shot

More common than allergic reactions are complaints that people don't feel well after receiving a flu shot.

"I hear this all the time as a physician," Alexander said. "You know, 'I got the flu shot, it made me sick,' or 'it gave me the flu.' And in actuality, when you get the shot, it revs your body up. It makes what we call antibodies, which are the things that fight off the virus itself. That process of making the antibodies feels very much like what happens when you’re getting sick."

She described the flu shot as being "one of our most powerful vaccines" and noted that for people receiving their first-ever flu shot, symptoms may be worse.

"There are different ingredients, there are different kinds of flu, so I think people had heard of the H1N1 [virus]," Alexander said. "We all got really nervous about H1N1. So there’s varying components of the H and the N that go together that make the flu virus, so there are all those different particles and sub particles, so our body is making antibodies to all of those. The first time you get a flu shot, you really don’t have very many of those antibodies, so your body has to do a lot of hard work to make those. That’s when you might feel the biggest impact."

Alexander compared that process to baking a cake.

"The more you keep getting the flu shot, the more it’s like putting icing on the cake as opposed to making the cake," Alexander said. "The first year, you’re making the cake. You’re getting all those ingredients together, you’re building the cake. As you keep getting it, you’re just icing it and putting on the decorations so you feel less of that, you know, achiness, chills, fever, those sorts of things that are the reactions we feel as our immune system’s working."

How to keep yourself and others healthy

Asked why it was critical for everyone who is able to get vaccinated to do so, even if they are young and relatively healthy, Alexander cited the need for herd immunity.

"If enough people get vaccinated, we are actually able to protect those who can’t get vaccinated," Alexander said. "So we’re not carrying the virus, we’re not carrying the infection or the disease and then spreading it to someone who, for whatever reason, can’t get the vaccine."

That means getting the vaccine, even if you don't believe you're personally at risk.

"You might go to church with someone who is at risk, you might shop in the grocery store with someone who’s at risk," Alexander said. "You might live with someone who’s at risk. You might babysit a premature baby who’s at risk. There are lots of ways that you will come into contact with folks who aren’t able to be vaccinated, and you getting vaccinated helps to protect yourself and them."

It can also protect you if you wind up getting that particular strain of the flu in years to come.

"You will have immunity to everything that you have been exposed to through the flu shot in an ongoing basis," Alexander said. "So if one year we don’t hit it quite right, you know, maybe it’s an H2N3, if you’ve been getting the vaccine all along, you’ve already built up some immunity to those subparticles. So even if you think you’re not at risk, really important to help prepare your immune system because one day you may be at risk for whatever reason, and now you’ve done your job in protecting yourself in anticipation of those days."

Alexander said that can also be helpful if you get the flu later in the season and the strain of the virus is different than what was in the flu shot.

"Getting the flu shot might mean that, okay, you know, we guessed the wrong strain, but we had it half right," Alexander said. "So if you still get the flu, you might get a much lower version than what you would otherwise. You won’t feel quite as sick, you may not need a hospitalization, you may not need IV fluids, you may not need an ER visit, you may not need an office visit."

Alexander also stressed the importance of washing one's hands frequently, even though she noted that the flu shot is the best protection against the flu.

"If your hands aren’t dry and cracked in the winter from washing, you haven’t washed enough," Alexander said.