The Clinton Herald, Clinton, Iowa

Z_CNHI News Service

March 4, 2014

Do flu shots cause runny noses?

— Influenza vaccines save millions of lives across the globe each year, but even heroes have their faults. A live attenuated flu vaccine, which contains weakened versions of the influenza virus, makes mice more prone to bacterial infections in their nasal passages. The vaccine used in the study is similar to FluMist, of which 13 million doses were distributed in the United States this year. The work helps explain why runny noses were an occasional aftereffect of FluMist in clinical trials.

"A study like this is an easy target for the antivaccine movement, but our findings shouldn't make a concerned parent less inclined to vaccinate their kid," says Michael Mina, a virologist at Emory University in Atlanta, who led the research.

Within the first few days of catching the flu, a person becomes susceptible to opportunistic bacteria. Microbes like Streptococcus pneumoniae and Staphylococcus aureus, which cause strep throat and staph infections, respectively, pounce on the exhausted immune system, causing secondary disease.

Mina wondered if attenuated flu vaccines could do the same. Some clinical trials of FluMist, for example, recorded an uptick in runny noses in children between the ages of 6 months and 5 years a week or so after they got the vaccine. But no study had attempted to figure out what might be causing the side effect by studying it in an animal model.

Mina and his colleagues mutated the H3N2 influenza virus to mimic the weakened strain included in the FluMist vaccine. Mice were then given this mock vaccine or a placebo either before or after they were exposed to S. pneumoniae or S. aureus.

Both bacteria flourished after mice were vaccinated, but only in their nasal passages and upper respiratory tracts, Mina's team reported last month in the American Society for Microbiology journal mBio. Although similar infections can cause runny noses in humans, they are much less dangerous than staph and strep infections in the lungs and lower respiratory tract. In fact, no infections at all transpired in the vaccinated mice's lower respiratory tracts, which explains why zero rodents experienced severe disease or died after bacterial exposure.

Even if the findings hold true in humans, a slight increase in the risk of a runny nose shouldn't prevent anyone from getting a flu shot, Mina says. Overall, getting vaccinated actually reduces your risk of bacterial infection by preventing influenza and, therefore, its host of possible secondary infections.

And at the end of the day, this is only a mouse model, says Vincent Racaniello, a microbiologist at Columbia University. Still, he says, it raises a mystifying question about this vaccine: "When you misdirect the immune response towards a virus, why do the bacteria take over?"

Next, Mina will search for human trends by heading to Bangladesh, where large-scale FluMist trials in children are ongoing. He will collect nasal swabs from vaccinated children to ascertain whether the patterns in his mouse model hold true. A city with the population density of Dhaka may witness an uptick in bacterial infections during mass vaccinations, he says.

According to Mina, some scientists in the field thought his study shouldn't be published because it casts a negative light on vaccines, but this research ultimately benefits the public, says Peter Palese, chair of microbiology at the Icahn School of Medicine at Mount Sinai in New York. "Vaccines are still the best ways of combating flu and many other diseases. Mice are not men, but it's important to learn about possible complications."

 

 

1
Text Only
Z_CNHI News Service
  • 072214 Diamond Llama 1.jpg Llama on the loose corralled in Missouri town

    A llama on the lam cruised Main Street Tuesday before it mistook a resident’s fenced backyard for a place to grab a meal and freshen up.

    July 22, 2014 2 Photos

  • When your doctor commits suicide, things get complicated

    When they call for appointments, patients are told they can't see their doctor. Ever. The standard line: "We are sorry, but your doctor died suddenly."

    July 15, 2014

  • NWS-HB0713-HowardMartin-004.jpg Airman laid to rest back home in Indiana six decades after death

    The mystery of what happened to a military transport plane that disappeared in the fall of 1952 into an Alaskan glacier was solved two years ago when a helicopter crew spotted the wreckage. But it took another two years to retrieve the remains of Airman Howard Miller and 16 other servicemen passengers. Saturday, Miller was laid to rest in his hometown of Elwood, Ind., with full military honors. Hundreds turned out for the funeral and burial services.

    July 13, 2014 2 Photos

  • This is what happened when I drove my Mercedes to pick up food stamps

     I climbed the ladder quickly, free to work any hours in any location for any pay. I moved from market to market, always achieving a better title, a better salary. Succeeding.

    July 8, 2014

  • Nation's first soda tax could come to Berkeley

    The Berkeley City Council unanimously decided last week to put the 1-cent-per-ounce tax on the ballot this November. Approving the tax would mean a major defeat for the soda industry, which has spent millions to crush the effort nationwide.

    July 7, 2014

  • taylor.armerding.jpg Declare your independence from empty slogans

    'Independence Day' is now an ironic celebration in a country where the president promotes government dependence over actual freedom, and where bumper-sticker slogans have replaced actual, independent thought.

    July 3, 2014 1 Photo

  • President Barack Obama mug Best president? Worst president? Don't read too much into those polls

    The questions about who are the best and worst post-WWII presidents are useless. What they mainly show is that Republicans are far more unified around a single story than are Democrats.

    July 2, 2014 1 Photo

  • What states can do on their own about immigration

    It's official: Congress won't take up immigration reform this year. This week, President Barack Obama said he'll use executive actions to change policies unilaterally.

    July 1, 2014

  • taylor.armerding.jpg Taxi owners, government patrons try forcing Uber to go 'off-duty'

    Uber gives urban passengers an enticing alternative. Rides on-demand arrive faster than taxis, are cheaper and cleaner, and get rated by customers. Rather than hail innovation, government enablers are helping the heavily regulated taxicab industry freeze out the upstart.

    June 27, 2014 1 Photo

  • The Internet has changed how we curse

    Relatively recent technologies — cable television, satellite radio, and social media — provide us with a not-too-unrealistic picture of how often people swear in public and what they say when they do.

    June 24, 2014

Front page
Clinton Herald Photos


Browse, buy and submit pictures with our photo site.

Poll

What are your plans for the weekend?

Enjoying the outdoors
Staying in out of the heat
Traveling
Other
     View Results
AP Video
Olympics 2014
Featured Comment
Featured Ads
Blue Zones Project
Parade
Magazine

Click HERE to read all your Parade favorites including Hollywood Wire, Celebrity interviews and photo galleries, Food recipes and cooking tips, Games and lots more.