I am on this earth because of influenza. This is the 100th year anniversary of the influenza epidemic of 1918 that infected 1/3 of the word’s population and killed 1 out of every 10 people infected. One of those people was my grandmother’s first husband. She was a nurse at a hospital in Durham, North Carolina and after her husband’s death, she met a physician fresh out of medical school, my grandfather. So, if the influenza epidemic had not have occurred, she and my grandfather would never have married and I never would have been born.
All told in 1918, 675,000 Americans died of influenza; that works out to 1 out of every 150 citizens. It was particularly lethal for young persons with the result that the U.S. life expectancy dropped from 49 years to 37 years for men and from 54 years to 42 years for women. The influenza strain that swept the world in 1918 was H1N1, the same strain that caused the 2009 pandemic of influenza that also seemed to preferentially kill young adults.
In 2009, 12,000 people in the United States and a half million people worldwide died of influenza. The problem in 2009 was that the strain of H1N1 that emerged was one that had not circulated in humans for decades – about 1/3 of people over age 65 years had antibodies to it from past infection but few young adults had ever been exposed to H1N1 and thus few young people had any immunity at all. Most years, 80% of influenza deaths are in people over age 65 but in 2009, 80% of deaths were in people under age 65. The H1N1 pandemic was therefore notable not for the total number of deaths (which was actually rather low) but for the fact that most of the deaths occurred in young adults. Even in non-pandemic years, influenza kills thousands of Americans. For example, last year, the CDC estimates that 80,000 Americans died of influenza and its complications, the most deaths in 4 decades.
As of December 22, 2018, the epidemiology of this influenza season (red line in this graph from the CDC) is falling in-between that of the 2016-2017 season and the 2017-2018 season. Most of the influenza being seen this year is once again the influenza A H1N1 strain with a smattering of H3N2 and influenza B. The flu claimed its first celebrity of the season this week when 26-year-old Fox News commentator, Bre Payton, died the day after developing influenza.
Yet still there are people who fear influenza vaccinations and refuse to get a simple and inexpensive flu shot that can save their lives. Here are some of the reasons for not getting a flu shot that I hear from my own patients:
- “I always get the flu every time I get a flu shot.” It is impossible to get the flu from a flu shot as there is no live virus in the vaccine. You are no more likely to get the flu from a flu shot as you are to get pregnant from taking a birth control pill. Yet nevertheless, more than half of parents believe that their child can contract the flu from a vaccine.
- “I don’t need a flu shot because I never get the flu.” This is like saying that you don’t need to wear a seatbelt because you’ve never been in a car accident. These people probably have had the flu but just didn’t realize it and attributed their symptoms to a cold or other illness. No human in innately immune from influenza. If you inhale a bunch of influenza viruses, then you are going to get the flu.
- “I don’t want a flu shot because it causes autism.” Yes, and the earth is flat, unicorns are real, and the tooth fairy plays poker with Elvis and the Easter bunny every Saturday night. Conspiracy theorists love this one. 20 years ago, in 1998, Andrew Wakefield published a paper in the journal, The Lancet, suggesting that the measles, mumps, and rubella vaccine was linked to childhood developmental disturbances. It turned out that Wakefield was funded by attorneys who were suing the vaccine manufacturer for allegedly causing autism. Wakefield was later found guilty of fraud, he lost his license to practice medicine, and the journal retracted his article. But the myth lived on and in 2005, journalist David Kirby published the book Evidence of Harm – Mercury in Vaccines and the Autism Epidemic: A Medical Controversy that alleged that thimerosal in vaccines causes autism. That same year, class action attorney Robert F. Kennedy, Jr. wrote an article in the Huffington Post making the same allegation (presumably setting himself up to win the mother of all class action lawsuits). Celebrities bought into this, most notably actor Charlie Sheen and former Playboy playmate, Jenny McCarthy, who have become the voices of anti-vaccine activism. Most influenza vaccines do not contain any thimerosal (the preservative that contains mercury). Even those that do contain thimerosal have the same amount of mercury as is in about 4 oz of canned tuna HOWEVER, thimerosal is broken down in our bodies as ethylmercury whereas fish contains methylmercury – ethylmercury is relatively harmless compared to methylmercury. The science is very strong: vaccines do not cause autism.
- “I don’t need a flu shot because last year I got one and still got the flu.” Yes, it is true that influenza vaccines are not 100% effective in preventing the flu. However, by creating protective antibodies against influenza, your body will be able to fight it off better so that even if you get the flu, it will be a milder case and you will be less likely to die. A study this year by the CDC found that patients who were admitted to the hospital with influenza and had gotten a flu shot spent four fewer days in the hospital, were 37% less likely to be admitted to the ICU, and were 2-5 times less likely to die compared to those patients who had not received a flu shot.
- “If I go outside in the cold and wet air, I’ll get the flu whether or not I get a flu shot.” Influenza is not an environmental microorganism, it lives in people and is transmitted by people. You cannot get the flu (or a common cold) by going outside when the temperature is low or when it is raining. In fact, if you spent all of your time outdoors in flu season, you’d be less likely to get influenza than if you are inside a building in close contact with other people who have the flu.
- “I always wait until December to get my flu shot so that it will kick in when the flu seasons hits.” Although it is true that antibody levels will peak several weeks after getting an influenza vaccine, a person cannot predict when they are going to be exposed to the virus in any given year. Getting a flu shot on Monday will not do much good if you are exposed to influenza on Wednesday. A person is better off getting the vaccine as early as possible in the flu season, ideally before the end of October. That being said, it is not too late to get vaccinated, even in January or February, as influenza usually continues to circulate in the United States until March or April each year.
- “I don’t want to get a flu shot because I might be pregnant.” If I only had one dose of the flu vaccine in my office, I would save it for a pregnant woman. There is no risk to vaccinating pregnant women and in fact, in the H1N1 pandemic of 2009, pregnant women were among those who were most likely to die when infected with the virus.
- “I don’t want a flu shot because I might get Guillian-Barré syndrome.” Every year, 3,000 – 6,000 Americans get Guillian-Barré syndrome (GBS) but every year, 10,000,000 – 50,000,000 Americans get influenza. The vast majority of GBS is not related at all to influenza. However, in 1976, the swine flu vaccine did have an increase risk of GBS with the result that one out of every 10,000 people vaccinated developed GBS. Since that time, the increase in GBS has been about 1 case for every 1 million influenza vaccines. The mortality rate of GBS is 2.8% and the mortality rate of influenza is about 0.16%. If you do the math, there are about 150 influenza vaccine-related cases of GBS in the U.S. each year with about 4 of these patients dying. Therefore, you are about 10,000 times more likely to die of influenza if you are not vaccinated than you are to die of GBS if you are vaccinated. As a general rule, I am not a gambler but I’l take the 10,000:1 odds any day.
- “I can’t take the flu shot because I’m allergic to eggs.” Because many influenza vaccines are grown in eggs, these vaccines can contain a tiny amount of egg protein. Nevertheless, the CDC recommends that people with egg allergies should still get influenza vaccinations. Patients with anaphylaxis from eggs should be observed in a medical setting after getting a flu shot. However, studies of over 500 patients with anaphylaxis from eggs and who received influenza vaccines found that none of these people developed a serious reaction from the vaccine. People who can eat cooked eggs are very unlikely to have any reaction to influenza vaccines. For those people who are still afraid of the influenza vaccine because of fears of egg allergy, there is a recombinant influenza vaccine (Flublok) that does not contain any egg protein.
- “Flu shots are too expensive.” Most insurance plans cover influenza vaccination and if a person without insurance goes to the local pharmacy, that person will pay about $40 to get it out of pocket. On the other hand, we spend about $10 billion per year in the United States on direct costs of flu-related illness and have another $16 billion per year in lost earnings from flu-related illness. That works out to each case of influenza costing about $530. So, instead of looking at the flu shot as costing you $40 each year, look at it as saving you $490 each year.
At the time of writing this blog post, influenza is already widespread in many states. In the next few weeks, my hospital’s nursing units and ICU will be full of patients with influenza-related illness, and some of them will die. Those patients who survive the ICU are always the first ones to ask for a flu shot the next year. But for those who die, like Bre Payton, influenza always gets the last word.
December 29, 2018