Crossposting from my FB page.
Okay, folks. Gather around the fire while Auntie/Doctor Harper shares her knowledge. There has been some posts lately about getting (or not getting) the flu shot, and I feel a need to weigh in.
Before we get started, let me address a few things:
First, (and I want you all to repeat this with me), this is NOT AN ATTACK AGAINST ANYONE! Get it? I’m not out to shame, belittle or vilify anyone. I’m just going to go over various arguments/ideologies that I’ve heard to give you the medical perspective with a little digression into social responsibility. Everyone clear on that? If not, read the above paragraph again.
Second, this will be only about the influenza vaccine. I may write something similar on MMR, TDaP and other vaccines on the schedule later.
Third, I will not be talking about the idea that vaccines cause autism (They don’t, but I’m not dealing with that here).
Strap in, folks, because it’s gonna be a long ride.
Argument 1: The flu isn’t such a big deal.
From a medical perspective, this is false! Let me quote from the CDC’s website on statistics from the PubMed report on the emergence of the H1N1 flu from 2009 to 2010.
“From 12 April 2009 to 10 April 2010, we estimate that approximately 60.8 million cases (range: 43.3-89.3 million), 274,304 hospitalizations (195,086-402,719), and 12,469 deaths (8868-18,306) occurred in the United States due to pH1N1.” (https://www.ncbi.nlm.nih.gov/pubmed/21342903).
But, you say, H1N1 was a new flu and the vaccine that year didn’t cover it. True. However, I show these numbers as an example of what can happen when there is no vaccination whatsoever against a strain of flu.
Now for strains of flu that aren’t out-of-the-blue, aggressive strains like H1N1 (or looking back, the Spanish Flu Epidemic that killed 500,000-700,000 people in the United States and an estimated 30-40 million people worldwide) the statistics are a bit murky. This is mainly because influenza as a cause of death isn’t mandatory to report to the CDC (which I think should be changed ASAP). However…
“The US Centers for Disease Control and Prevention (CDC) estimates that flu-associated deaths in the US ranged from about 3000 to 49,000 annually between 1976 and 2006.” (http://emedicine.medscape.com/article/219557-overview#a6)
Influenza-associated deaths in children are reportable, however and…
“Since influenza-associated pediatric mortality became a nationally-notifiable condition during the 2004-2005 season, the total number of influenza-associated pediatric deaths has ranged from 37 to 171. (This excludes the 2009 pandemic, when 358 pediatric deaths were reported to CDC during April 15, 2009, through October 2, 2010.)” (http://www.cdc.gov/flu/about/season/flu-season-2015-2016.htm)
And this is only the death data. Influenza related hospitalizations are much higher.
Now, I must acknowledge that Argument 1 has a grain of truth in it. Generally, influenza is dangerous in the very old or the very young, especially if those people also have co-morbidities like lung disease, suppressed immunity, diabetes, etc. For the majority of the population, getting the flu means having to endure a particularly shitty couple of weeks. In fact, the high morbidity/mortality of 2009-2010 and the Spanish flu in 1918 was because it killed off more young adults than it did the elderly or children. (Why this happened is a subject for another discussion. Let me know if you want details.) This, naturally, leads into…
Argument 2: I’m young, healthy with no chronic health issues. Why should I bother with getting a flu shot? Other people who really need or want it can get it.
Well, the short answer is “It’s not that simple”. The longer answer is “Not everyone who needs the flu shot can get it and depend on herd immunity to protect them.” You see, for some people, regardless of their need for or desire to get the flu shot, that is simply not an option. An anaphylactic allergy to eggs is an absolute contraindication for getting the shot as the flu virus used to make the vaccines have to be grown in eggs. People can also have allergies to other components of the vaccine. A person with a history of Guillian-Barre Syndrome has to carefully weigh risk/benefit when considering this vaccine (and, since this syndrome involves progressive paralysis that usually resolves, many don’t take the risk). Children younger than 6 months cannot receive the vaccine (but they CAN still catch the flu). Some people are on immuosuppressive therapy such as chemotherapy or organ transplant maintenance and may not respond adequately to the vaccine. And some completely healthy people, through some genetic quirk, simply do not develop antibodies in response to a vaccine no matter how many times they get it. These people rely on herd immunity for protection.
What is herd immunity? You might say it’s a exploitation of the fact that the influenza virus is an obligate parasite. Unlike certain bacterial diseases (tetanus, botulism, leprosy) which can survive outside a human body for weeks or even years, influenza must have a living host to survive and spread. That means, if there are not enough vulnerable hosts around, it cannot spread. If everyone who is medically able to both get and respond to the vaccine get the shot, the infection is much less likely to get to this much smaller population because there aren’t enough “stepping stones” to reach them.
But, you might say, in the unlikely event that I get the flu, I’ll just stay away from those people. Well, I congratulate you on being financially secure enough to be able to take off work for 10 days (because the infectious period is 5-10 days). But isolating yourself from the first sniffle wouldn’t work because YOU CAN SHED THE VIRUS A FULL DAY BEFORE YOUR FIRST SYMPTOM. And just how do you know who “those people” are? Yes, babies are obvious, but lots of people with severe illness or funky immune systems wander around outside of a hospital all the time. They’re not wearing a badge with a scarlet V for “vulnerable”. By eroding herd immunity by refusing the vaccine for other than medical reasons puts your fellow man/woman/gender-unassigned at risk.
Argument 3: I’ve never had the flu and I’ve got such a strong immune system that I’ll likely never get the flu.
This argument is the medical equivalent of “I’ve never been in a car wreck, so I don’t need to wear a seatbelt.” It is also not exactly true. I’m NOT calling you a liar. I’m just wanting to say that a more accurate statement would be “I’ve never had the symptoms of flu”. Because it is possible for you to catch the flu and experience mild to absent symptoms.
“British researchers who tested people for influenza antibodies before and after each flu season for 5 years found that an average of 18% of them appeared to have contracted a flu infection each season, but only 23% of that group got sick, according to a report in The Lancet Respiratory Medicine.” (http://www.cidrap.umn.edu/news-perspective/2014/03/uk-flu-study-many-are-infected-few-are-sick)
Although we do not yet have enough evidence to say for certain that people with completely asymptomatic influenza are a factor in large-scale flu transmission (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2646474/), I’m greatly concerned that people with mild cases that they might not realize is actually flu may be a significant risk to herd immunity.
Argument 4: They never really know if they’ve got the strain right in this year’s vaccine, so why bother?
Well, influenza is a tricky little bastard. Not only does it have a high mutation rate on its own, but it can also be passed back and forth between humans, pigs and birds. This increases the rate of antigenic shift and drift that radically changes the virus’ genetics. Given these features, it’s pretty remarkable that they have the success rate that they do in picking the strains for the vaccine…especially since they have to make the decision in the February preceding the current flu season in order to have time to make the vaccine. However, even if there is a mismatch, having antibodies to one variety of influenza can give you partial protection against the others so that, if you do get the flu, you’ll likely have a less severe case. Insisting that a vaccine must be 100% effective or else it’s useless is falling prey to the Nirvana Fallacy.
Argument 5: But the last time I got the flu shot, I got the flu!
The flu shot that adults get is made from an inactivated (i.e. dead) virus. Therefore, it cannot give you the flu. I hear you protesting now. “But I got sick the day after I got the flu shot!” To which I ask, “How long were you sick?” The flu lasts generally for 1-2 weeks. If you had symptoms for just a couple of days, this is likely your immune system reacting to the antigens to make antibodies. If you were sick for 1-2 weeks, well, correlation doesn’t always mean a causal link. First of all, there are a ton of other viruses that cause “flu-like illness” that are not even in the same family as influenza. Second, if you went to the doctor and tested positive for influenza, bear in mind two things. 1) The incubation period for influenza is generally two days, but it can run anywhere between 1-4 days. You may have been infected before the shot and didn’t know it. 2) It takes two weeks from getting the shot to the point where you’ve built up enough antibodies to be protected. That means you can get the shot on Monday, come in contact someone with flu later that day, and wake up the next morning sick.
I hope this is helpful. Again, I’m not trying to vilify anyone. I just want to make sure you know the facts before you decide whether or not to get the jab.
|
annoyed.
excited.