Is everyone skipping vaccines?

We're immunized! Are you? by Pixabay

We’re immunized! Are you? by Pixabay

This post originally appeared on the Disease Daily on Aug 25, 2014. It has been republished here with permission from the authors. 

By Jane Huston and Robyn Correll Carlyle

August is National Immunization Awareness Month. To celebrate, we are going to tackle a myth about vaccination every Monday throughout the month. View previous posts here, here, and here.

In our last myth-busting post of the month, we’re taking on the impression you might get from reading blogs or news online about vaccines: that droves of parents are deciding not to vaccinate their kids anymore. We know that with all the anti-vaccine chatter on social media or in the news, it often feels like everyone and their next-door neighbor is delaying, cherry-picking, or downright refusing vaccines.

But vaccination is very much still the social norm. In 2012, among US children ages 19-35 months, 92.8 percent were fully vaccinated against poliovirus. Ninety-four percent were vaccinated against diphtheria, tetanus, and pertussis (three diseases prevented with the DTaP shot). Overall, 80 percent completed three important childhood series: DTaP, polio, and MMR.

If the majority of kids ARE getting vaccinated, why do we seem to only hear about those who aren’t? It’s a case of a silent majority versus a very vocal minority.

The fact is that nationally, vaccination coverage is relatively high — but not high enough. We need exceptionally high immunization coverage against exceptionally infectious diseases, like measles. And worst of all, national averages can hide some local variances that create dangerous powder kegs for infectious disease outbreaks.

For example, in California in the 2007-2008 school year, 92.1% of kindergarteners were fully immunized — not bad, right? Well, unfortunately it’s not that simple. Someplace like Glenn County reported 98.5% immunization rates — you go, Glenn Co! But… on the other hand, Nevada County reported that just 75.5% of its kindergarteners were fully immunized. That’s not high enough to ensure herd immunity against many diseases, like measles or whooping cough. One infectious traveler entering that under-protected community could be the spark to start an outbreak.

One potentially overlooked factor is why those kids are not fully immunized. And here the story gets a little more nuanced. There’s a big difference in being unvaccinated and undervaccinated. Unvaccinated children haven’t received a single vaccine; undervaccinated children have received one, some or even most of the vaccine schedule but are still missing some important shots. And it turns out these two groups are pretty different.

Researchers looked at a random sample of over 20,000 children, from 1995-2001 to learn a little more about those two groups of children. What they found was that only 0.3 percent were completely unvaccinated (here’s that vocal minority– these parents were more likely to report concerns around vaccine safety). It’s actually an incredibly small amount of people who are refusing all vaccines (good news!).

But… over 35 percent of children were undervaccinated to some degree. These children were statistically more likely to be racial or ethnic minorities, have a mother with low educational attainment, and live in poverty. These likely aren’t kids whose parents are refusing to let them get vaccinated, but they might be having trouble seeing a provider regularly or paying for vaccines. They’re falling through the cracks of the health system. This group is arguably the most important group for public health officials to focus on for outreach and more services.

Those who choose to delay or skip vaccines by choice — because of safety concerns or worries about the schedule — are still only a tiny portion of our population.

Almost everyone IS vaccinating. But to keep it that way, the silent majority needs to get louder about their support for vaccination.


Jane manages the Vaccine Finder project at Health Map, the host site of the Disease Daily. Robyn is a contributing writer for the Disease Daily and works as a project manager for a non-profit focused on vaccine education. Both are fully up-to-date on their immunizations.

Flu shots are for everyone – not just you.

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by Daniel X. O’Neil

This article originally appeared on the Disease Daily on December 2, 2013. 

By Jane Huston and Robyn Correll Carlyle

Two out of five.

When public health officials make their rounds to encourage everyone six months of age and older to get the flu vaccine this year, two out of every five of you won’t.

Maybe you’re too busy. Maybe you don’t think it’s that important. Maybe you think that the flu vaccine would give you the flu (which it can’t).

“I’m young and healthy,” you might say. “I never get sick. And even if I do, it won’t be that big of a deal.”

But here’s the thing: It’s not just about you.

If you have influenza, you can pass the virus on to other people, sometimes without even realizing you’re sick. The communicable period (the time during which an infectious agent may be transferred from an infected person to a susceptible person) for influenza is between five and seven days, but can start one full day before you feel any symptoms. Some people infected with the virus never develop any symptoms, but are still contagious. That means you are able to infect others with influenza without feeling sick yourself. It seems incredibly unfair, but hey, all’s fair in love, war… and infectious disease.

It can be normal, everyday interactions that you wouldn’t think twice about. You touch doorknobs after discreetly wiping your nose. You squeeze onto mass transit and give out a little cough. You stand next to people in line at the grocery store and chat with them in close proximity. All of which are prime opportunities for influenza to jump from one person to another.

When you leave yourself open to the flu, you also leave yourself open to spread that flu to other people. And what might not be “that big of a deal” to you, can be a very big deal to someone you care about.

Every year between five and 20 percent of Americans will be affected by influenza, and at least 200,000 people are hospitalized annually because of it.

“Hang on now,” you might say. “Can’t we just vaccinate the people most likely to die or be hospitalized from the flu?”

Here’s the thing. Not everyone can be immunized against the flu. Babies under the age of 6 months and those who are seriously ill, for example, are not able to get the vaccine. And even older adults (the population most likely to die or be hospitalized due to flu) might not develop a strong enough immune response even after they’ve been vaccinated.

That’s where you come in. Something as simple as getting your flu vaccine helps to avert an average of 2 million cases of the flu and 18,000 flu-related hospitalizations every year. Because you can’t spread the flu if you never get infected.

But if we can’t appeal to your sense of civic duty, how about your pocketbook? Every year, the flu results in an estimated 31.4 million doctors visits and direct medical costs averaging $10.4 billion annually. Because people are too sick to go to work — or in some cases lose their life to the flu — we forfeit an average of $16.3 billion every year in projected lost earnings.

If you get infected with the flu and pass the virus onto another unsuspecting soul, that could mean days of lost pay — or longer if they have a family that becomes infected as well. After all, each infected person is likely to infect an average of 1.3 more people.

So for two out of five of you, this is our plea. Please don’t be that guy. Don’t be the one who could have received the flu vaccine but didn’t and now everyone in your office/kid’s school or daycare/grandmother’s assisted living facility has come down with it, too. You’re better than that. Besides, no one likes the sick guy.

Get your flu vaccine.


Jane manages the Vaccine Finder project at Health Map, the host site of the Disease Daily. Robyn is contributing writer for the Disease Daily and works as a health educator for a non-profit focused on vaccine education. Both are fully up-to-date on their immunizations.

The Summer My Dad Got Pneumonia

Angelina with her father, Larry

Angelina with her father, Larry

By Angelina Albert, MPH

In The Immunization Partnership office in Houston, there is a wall covered with large canvas print photographs. Each photo has a story connected to it of someone impacted by a vaccine-preventable disease. These stories remind us why we do what we do. I look at those photographs every day and reflect on what those families had gone through – what could have been prevented.

This past summer, our family experienced a vaccine-preventable disease story of our own.

It all started in July. Like many afternoons, I called my dad on my way home from work. He sounded weak and hoarse when he picked up the phone. I asked him how he was doing, and he told me how terrible he felt. He had woken up in the middle of the night gasping for air; he had never felt so bad. He wondered if he was possibly allergic to my mom’s recently adopted cat. I just assumed he had been working too hard and needed to rest. Even so, I was still very concerned. When I was young he had an emergency quadruple bypass.  Now – 22 years later – he is very healthy. He goes for long walks each morning and maintains a low-fat diet. But like any doting daughter, I still consistently worry about him.

I thought about him that evening and texted my mom to see how he was doing. She was coming to Houston that weekend and would bring the cat with her to see if his symptoms improved. We chatted about other things, and I assumed he would get better. She called me the next day from the emergency room. My dad couldn’t breathe.

When they took him into the ER, he was immediately diagnosed with pneumonia. They admitted him into the hospital, where he was put on oxygen and antibiotics and stayed for several days. His case was quite severe. The nurse asked him if he had received the pneumococcal vaccine, and he was pretty certain he hadn’t. Knowing where I worked, he called me to ask about it. After learning more about the vaccine from my colleagues, I told him that adults older than 65, especially those with chronic diseases (such as heart disease), should get the vaccine. He wasn’t even aware it existed, let alone that he needed it. He was annoyed that his doctor had not recommended it.

His hospital stay was extended when he developed an unusual swollen pain on his shoulder. My dad has his own business, and his anxiety level increased as he sat in the hospital room unable to work.  Now, months later, my dad is back at work, but still lacks energy.

Though my dad had made sure to receive the flu shot each fall, he had never received – or even been aware of – the pneumococcal vaccine for adults. He is older than 65, but is not frail or sickly, and to him developing pneumonia seemed to come out of nowhere. Seemingly healthy or not, it is strongly encouraged that adults his age (65+) receive the vaccine. I made him promise he would protect himself, and as soon as he was well enough, he went to the doctor to get the vaccine.

In 2010, 1.1 million people were admitted into the hospital for pneumonia in the United States, with a length of stay averaging 5.2 days. Among those with pneumonia in 2010, 49,597 people died from it.

My dad is one of the lucky ones; he pulled through. But my family will never forget that experience.


Angelina is a Development Specialist with The Immunization Partnership.

Six Signs the Article You’re Reading is Bad Science

by Vmenkov

by Vmenkov

This article originally appeared on the Disease Daily on Jul 16, 2014. It has been reposted with permission from the authors.

By Jane Huston and Robyn Correll Carlyle

One reason we feel so strongly about the role of vaccines in public health is because of the massive amount of good data and quality studies that support them. And that’s why it’s frustrating when media, the Twittersphere, or the internet in general circulate rumors and poorly designed studies attacking vaccines.

The thing is– science is hard. Like, really hard. People study for up to 10 years to be a qualified researcher. And reading scientific literature can be a bit tricky. We can’t catch you up to the guy or gal who’s devoted an entire career to vaccinology or epidemiology, but here’s a handy cheat sheet to help you spot the “junk science” when it comes across your news feed:

1. It confuses correlation and causation.

This is a big one, and possibly a mantra you’ve heard before: correlation does not equal causation. Correlation is a statistical term that simply means the way two variables fluctuate appear to be related in some fashion. Any fashion. Maybe variable A going up happens at approximately the same rate as variable B going down. Maybe they increase together. Maybe it’s not a linear relationship (but that’s a bit more complicated). What’s most important to remember here is we absolutely cannot assume that one is causing the other. We simply don’t have enough information since all we know is how the variables are changing.

Take this example of Nicolas Cage films and drowning deaths. That plot looks pretty good right? And the correlation coefficient is a fairly solid 0.66. Could it be that Cage’s action-packed thrillers are inexplicably driving people towards backyard swimming pools? Anything’s possible. But the two almost certainly have nothing to do with each other and are, instead, a total coincidence. Often when two variables are correlated, there is actually an unknown third (and potentially fourth and fifth) variable that is affecting both of the events you’re examining.

2. Its sample size is small.

People suffer from a wide range of medical issues every day — sometimes they are caused by what you’re studying, but sometimes it’s just by chance that the participants being studied develop an issue. Out of a study sample of three, having one guy get hit by a bus would look like a significant trend. The larger the sample size, the less impact those random occurrences will have on your data.

3. The study is uncontrolled.

Not uncontrollable like your two-year-old nephew on a sugar-high, but uncontrolled as in lacking a control group. A control group provides a researcher something to which to compare results; it’s the closest way to estimate the counterfactual. Did the subjects get better over the course of the experiment because of a drug being tested, or would they have improved anyway? A control group that is similar to the experimental group in every way EXCEPT for the intervention can help you answer that question.

4. The results are not replicable.

One study alone (even a well designed, large-scale one) can’t prove anything. All it can do is contribute to the body of work already done by the scientific community. It takes several studies coming to the same conclusion to say anything with confidence — and even then we can’t be 100% certain. Science is purposefully self-correcting. Researchers rely on each other to validate their results. If no other researchers have been able to replicate a study’s findings, that’s a red flag.

On a related note, beware of those researchers who are only citing themselves. If an author says that there is “substantial evidence to support” a given link or a particular cause, check out the citations. Have several different research groups provided evidence to support the link? Or is it just one name (the author’s) that keeps popping up? If that author is the only one who seems to be providing that “substantial evidence,” it’s worth taking with a fistful of salt.

5. There’s a conflict of interest.

This is a sensitive but important point. When publishing a paper, authors must disclose the source of funding for their work as well as any other relevant conflicts of interest, such as ownership of a related private company. This does not necessarily invalidate the results of the experiment, but you should definitely be aware of any potential bias when reading results. If the author has a lot to gain from the study and the results seem glowing with no down-sides or limitations, be suspicious.

6. It’s published in a journal that’s not peer-reviewed.

Whenever possible, try to read the original journal article instead of relying on the popular press. Articles in general news media can be a great source to find out about new and interesting research, but remember they are necessarily interpreted by a reporter (in best cases by a science writer with a background in science; in the worst cases it’s a press release). While you’re reading the original article, make a note of the journal it appears in. Is it a reputable publication, like Nature, Journal of American Medical Association or the New England Journal of Medicine? Did articles have to pass a peer-review process, meaning that other experts read the manuscript, asked probing questions, pointed out any errors, and addressed limitations? This process is by no means perfect; mistakes can certainly still get through peer review and show up in reputable sources. But on the whole, a study appearing in a respected, peer-reviewed academic journal carries more weight than one published on a personal blog.

There’s another deadly threat — single-issue shill “journals” published entirely to push an agenda. This is the worst possible abuse of the scientific process. Some people, after being spurned by reputable journals, will go so far as to create their own journals to fabricate a veneer of legitimacy for their flawed ideas. These biased publications are a wolf in sheep’s clothing. Avoid them at all cost.

In the age of the internet, it’s getting harder to tell good science from bad. But if you follow this guide, and approach scientific articles with a healthy dose of skepticism, you’ll do fine.


Jane manages the Vaccine Finder project at Health Map, the host site of the Disease Daily. Robyn is a contributing writer for the Disease Daily and works as a project manager for The Immunization Partnership. Both are fully up-to-date on their immunizations.