CDC Apology for Poor Flu Vaccine?

Did the CDC actually apologize for a poor flu vaccine last Wednesday?  There are multiple reports that it did, but they are not strictly true.  I was immediately skeptical when I first heard this, not because I trust the flu vaccine, but rather because I seriously doubt the CDC would issue an apology even if this year's vaccine did not work at all.  According to Snopes, my skepticism is fully warranted.  The CDC did not issue an apology, and they also did not alter any recommendations regarding getting the vaccine.  They did, however, issue an advisory stating (in different words) that this year's vaccine kind of sucks.  This is not entirely their fault, because flu vaccines have to be made far in advance, so selecting the right strains is mostly guess work.  Further, the flu mutates fairly quickly, and even the best guess cannot protect against a totally new strain.  The common strain this year happens to have drifted enough that the vaccine is somewhat less effective than usual.  The point of the advisory was to let doctors know that flu cases should be treated more aggressively, since the vaccine is not likely to help as much.

What does this mean about getting vaccinated?  Well, the CDC has not changed their recommendation, and they recommend that everyone get vaccinated.  This season's vaccine will still help, just not as effectively.  Even vaccinating for the wrong strain will help at least a little, because there are still similarities.  For some people, however, it will not help at all, and for others it will help, but not as effectively.  This means, even with vaccination, more people will get the flu this year, and those that do will probably have more severe symptoms than usual.  The CDC advisory recommends that doctors use anti-viral drugs early on for high risk patients to mitigate with this.

I want to present the actual numbers, for several reasons.  The first is to show that the difference is actually not as big as it is made out to be.  The second is to show that the flu vaccine was never that effective in the first place.

This article goes over the data in more detail than I will, and it is much more clear than the CDC advisory.  It also references a study done around 2 years ago on the effectiveness of the flu vaccine.  It turns out that the flu vaccine has never been much more effective than 59% on average.  A newer version of the vaccine has shown higher effectiveness, but some studies have shown it to be entirely ineffective in children when administered as a nasal spray (to my knowledge, the most common delivery system for it).  The one currently being administered, however, is the one with 59% effectiveness.  This year's vaccine is estimated at 48% effectiveness.  That is not an enormous drop, but it is significant, and it does put effectiveness below half.  The part that is bad is that the effectiveness was so low in the first place.  (Admittedly, a few studies before the 2012 one estimated between 80% and 90% effectiveness.  Flaws in those studies prompted the most recent one.  The medical industry honestly thought effectiveness was between 80% and 90% until recently.)

Does this low efficacy warrant second thoughts about getting vaccinated?  Probably not.  There is a risk factor that should be considered when making this decision, but for most people, even a 48% effectiveness is probably a good gamble for what is a fairly cheap vaccine.  Knocking down almost 50% of flu cases before they start should reduce the number of cases by well over 50%.  This is because those who do not get the flu will not be contagious, so they will not spread it.  Reducing the spread may ultimately have more value than preventing an individual case when it comes to vaccinating.

I have discussed the risk factor before.  Pre-drawn vaccines typically contain latex.  Also, some other common ingredients of vaccines are allergens.  Cheap vaccines are especially likely to contain allergens.  For people with latex allergies, or even a family history of latex allergy, minimizing the number of vaccinations may be wise.  For people who have ever had a reaction to a vaccine, the risk may also be especially high.  For these people, it would probably be a good idea to weigh the risk of allergies against the vaccine that will only reduce your chance of getting the flu by 50%.

The flu vaccine is very complicated.  It is more or less a guessing game.  On average, it will reduce your chances of getting the flu by around 60%.  Each year, however, the exact percentage is different.  In one year, it measured at 10%.  In others, it has measured closer to 80%.  In cases where the risk of allergies is very low, the cost of the vaccine is low enough to make it worth gambling on.  In cases where the risk of allergy is high, gambling may be unwise regardless of how low the price is.  Overall though, the flu vaccine is not 100% effective, and it should not be treated as being that effective.  Even at a low efficacy, it does have some benefits to heard immunity, but the current vaccine will never eliminate it entirely.  The flu vaccine does little more than keep the flu in check.  Refusing to vaccinate for the flu because of unfounded fears actually has little impact on the overall effectiveness, so long as plenty of other people vaccinate.  This year, the impact of choosing not to vaccinate is even lower than usual.  None of this is the fault of the CDC.  It is a persistent problem with trying to vaccinate against a disease that is highly adaptable and widespread in a large human population.  That said, we have known about the low effectiveness of the vaccine for at least two years now.  It would be nice if the medical establishment would stop misrepresenting it as a highly effective solution.