Pharmacy & Healthcare

Flu: Who Knew?

Walgreens experts sort fact from fiction regarding common flu vaccine myths.
Josh Gaby, Walgreens Stories
Remember the 2018-19 flu season? If it feels like it was yesterday, it might be because it seemed like it would never end.
Flu activity peaked late, in February and March, as opposed to December and January – a continuation of an ongoing trend over the last few years. But Walgreens was still seeing notable flu activity into May, according to the Walgreens Flu Index.
The Walgreens Flu Index uses prescription data for antiviral flu medications at our pharmacies to pinpoint the top states and markets for flu activity in the U.S. and Puerto Rico, as well as where flu has increased the most from week to week. 

Which begs the question:  If you got your flu shot way back in August, when the vaccine first became available, were you still protected by May?
Would it not be better in the future to wait and get your flu shot later –
not in August but, say, closer to the holidays?

Pharmacist Alex Novielli, manager of immunizations for Walgreens, confirms that the protective effects of a flu shot received in August or September will last through the entire flu season for most patients – eight or nine months – even if the season ends as late as the last one did. There’s one exception: “This past August, the CDC began advising that seniors consider delaying getting their flu shots until September or October of a given flu season, because with some older adults, there is concern their immune systems may weaken over time and that if they’ve gotten the shot in August, they won’t be fully protected by the spring,” says Novielli.

For everyone else who’s not a senior, August or September is still the recommended time to get the flu shot – and it’s best for everybody to get it before the end of October, according to the CDC. In other words, if you haven’t gotten yours yet in November, or if your family members haven’t received theirs, take care of it soon. The flu is coming – it’s just a matter of when.

“It can take up to two weeks for your body to produce antibodies against the flu after you’ve received the shot,” says Novielli, who gets his own shot every September. “Flu season is unpredictable. Despite what we’ve seen in recent years, it could just as easily peak in November or December, when there’s more travel and close contact at the holidays, and then you’re vulnerable to getting the full-blown flu if you’re not protected before that.”
With all the conflicting information out there, we asked our experts to help with  some more myth-busting around flu vaccines to help set the record straight.
MYTH: Getting the flu shot can give you the flu.

Nope.  Injectable flu vaccines are not infectious because they’re made with “killed” or inactive flu strains, says Novielli. In the past, Walgreens did offer a “live” vaccine option in the form of a nasal spray, but we stopped carrying it after the 2015-16 flu season. “You may see some brief, minor side effects such as redness at the injection site, muscle soreness and fatigue, just to name a few, but it’s nothing compared to getting the actual flu,” says Luis Solano, pharmacist on assignment in Immunization Services. “The flu can be accompanied by muscle pain, chills, dehydration, loss of appetite, head and chest congestion, shortness of breath and swollen lymph nodes. The flu can also have you in bed for days. So the tradeoff is experiencing a few brief side effects compared to the symptoms of the flu.”
  1. Flu season starts in the Southern Hemisphere, where the seasons are the opposite from what they are in the Northern Hemisphere (meaning winter is June through August).
  2. The World Health Organization (WHO), after studying how flu has impacted the Southern Hemisphere, releases its predictions to vaccine manufacturers in February about which four flu strains are likely to be the most virulent in the Northern Hemisphere.
  3. Flu vaccine manufacturers prepare test batches of two kinds of vaccines: trivalents, which contain the top three predicted strains, to be given to patients 65 and older; and quadrivalents, which contain all four predicted flu strains, for other patients.
  4. U.S. manufacturers send their test lots to the FDA for approval.
  5. Once the lots are approved by the FDA, mass production can begin to make sure the vaccines are available to providers such as Walgreens by August, the start of our flu season. The vaccines are distributed to Walgreens in two forms: multidose vials containing 10 doses of vaccine per vial, and individual pre-filled syringes that our pharmacists dispose of after the shot is given.
Walgreens flu vaccines are supplied by multiple different manufacturers. The reason? If one manufacturer is experiencing production delays for any reason, we can still count on the others. “You don’t want to put all your eggs in one basket with a single manufacturer,” says Novielli.

MYTH: If the Southern Hemisphere had a bad flu season, the Northern Hemisphere will have a bad one, too.
Not necessarily. “This year, the CDC is predicting it could be a really severe flu season here in the U.S. – the reason being that Australia in particular had a really bad flu season,” says Novielli. “But it could also end up being mild. We just don’t know.”
MYTH: I heard the flu shot is only 40 to 50 percent effective. That’s not good.
When the CDC says a flu vaccine is 40 to 50 percent effective, that means that of the people who receive the flu shot, 40 to 50 percent of those who are then exposed to the flu will experience no symptoms whatsoever. The rest might still experience mild or reduced symptoms. But it sure beats the full-blown flu. “If you don’t get the flu shot at all, you’re at risk to experience far more severe symptoms than the person who got the flu shot,” says Novielli.
Given the technologies currently available and the unpredictability of flu strains – which can sometimes mutate during the course of a season – 40 to 50 percent effectiveness is a sign of a relatively good match between the flu strains the WHO recommended for the vaccine vs. the flu strains that are actually circulating, says Novielli. 
MYTH: I got a flu shot last season. I can skip a season and I’ll be fine.
Hold on. While it’s true that some of the flu strains in the vaccine may be the same or only slightly tweaked from the season before (because those strains are still circulating and still considered the most virulent by the WHO), your immune system still needs a “reminder” in order to be as protected with flu antibodies as it can be. “You still need to get a flu shot every season to have the full possible protection,” says Novielli. 

MYTH: If it’s later in the flu season and I haven’t gotten a flu shot yet, there’s really no point.
Just because the flu season seems like it’s over doesn’t mean you can’t still be infected. “While it’s best to get immunized early during flu season, it’s never too late,” says Christie Reyling, a pharmacy manager in Columbia, Ill. “Although it does take about two weeks after immunization for your body to build up the antibodies to protect you against flu, as long as there’s circulating flu virus, there’s still reason to protect yourself and your loved ones.” 
MYTH: Pregnant women shouldn’t get a flu shot.
Not true. They should. Pregnant women are one of the main patient populations – along with young children and seniors – at a higher risk for complications if they contract the flu.

Is there any group of patients who shouldn’t get a flu shot? According to the CDC, only one group needs to take particular precaution: people with egg allergies, since flu vaccine is incubated in eggs as part of the manufacturing process. Patients with egg allergies are advised to get their flu vaccine at a doctor’s office, clinic, health department or other inpatient or outpatient medical setting – not a Walgreens pharmacy – where the provider can recognize and manage a possible allergic reaction.
MYTH: I’m not a child, a senior or pregnant. I don’t really need a flu shot because I’m a healthy adult who doesn’t get sick a lot.
“Even in a healthy person, illness from the flu can become severe,” says Jeremy Sullens, a Walgreens pharmacist in Tucson, Ariz. “Not getting the flu shot increases the chance you may get the flu, miss work, need an appointment to see a doctor or need to get a medication that might cost a lot more than the shot, which is no cost through most insurances. You might also get other people sick. The vaccine not only protects you, but helps protect friends, family, children, the elderly, even those you pass in public.”
MYTH: I was sick with vomiting even though I got a flu shot last year. This means the flu shot didn’t protect me!

You’re probably confusing influenza with a stomach bug. “The flu vaccine protects us against the influenza virus, which infects the respiratory system – your nose, throat and lungs – to cause the flu,” says Kacee Verhovec, a specialty pharmacy resident in St. Louis, Mo. “Typically, the influenza virus doesn’t cause nausea and vomiting. The ‘stomach flu,’ on the other hand, is caused by rotavirus or norovirus, which infects the digestive system, causing nausea, vomiting, abdominal pain and/or diarrhea.”

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