Herd Immunity: A Scientific Fact

Many anti-vaxers (Mr. Hubbs included) seem to have a problem with the concept of herd immunity as if it is a myth, so I thought it was worthy of discussion to get the facts out there.  First of all the idea of herd immunity is that if enough people area vaccinated from a particular disease and therefore cannot contract that disease and/or pass it to others, then those who are not vaccinated will be protected.  Under most cases the threshold for such immunity equates to approximately 85% of the population being vaccinated for any given disease.

Unfortunately if the group that is not vaccinated grows too large, the 'herd' or population can no longer prevent diseases from being transmitted from person to person and this herd immunity loses its effectiveness.  The real issue here is that we always know there are a number of people who can't get vaccinated for one reason or another.  Maybe they are on chemotherapy or maybe they are on immune suppressive therapy for a chronic disease or maybe they have severe allergies that prevent them from receiving a specific vaccine (some vaccines use egg proteins for example).  These people have no choice but to skip a vaccination due to their other existing conditions, and they rely upon the rest of us to protect them. 

Dr. Paul Offit (probably one of the most well know and respected experts in the field of immunology and vaccinations) recently stated there are 500,000 people (I'm assuming he means people in the US) who fall into this category.  That means it is up to the other 300 million of us to get vaccinations in order to protect those who can't protect themselves.  Granted getting a vaccination is not a totally selfless act as it protects the person who gets the vaccination as well, but knowing it can prevent spreading disease to others is surely an added benefit.

Generally this system works fine, but in recent years due to fear mongering by pseudo-celebrities like Jenny McCarthy and due to fabricated studies like the one pushed forth by the now discredited Andrew Wakefield, there has been a growing number of people who are skipping their vaccines simply because they are too ignorant of the real science and too scared to take a chance.  To some degree these people are simply being selfish because they think the rest of us will protect them, but on the other hand these people are being dangerous because their lack of vaccinations means they can (and often do) contract diseases which are spread onto others.

Case in point, California is now under the worst pertussis outbreak in the last 50 years which has resulted in over 1,500 people contracting Whooping Cough and at least 10 deaths thus far.  The root cause of this outbreak?  People who skipped their vaccinations and thus spread the disease to others.  The primary reason for a growing number of people refusing to vaccinate their children or receive vaccinations themselves has been the discussion about a possible link to autism and all of the media attention which has surrounded the issue.  However, if you actually drill down on the issue you will find numerous peer-reviewed studies which have been performed that show no link between vaccines and autism, yet not a single peer-reviewed study anywhere which proves such a link exists.

This is generally the point where Mr. Hubbs would profess that the Wakefield "study" (not really a study, but more of a paper) proved such a link, but truth be told even when the Wakefield paper was published, it still was not able to prove such a link exists and never even claimed to.  Besides the fact that Wakefield didn't make the specific claim that the MMR vaccines causes autism (he merely eluded to a potential risk) and aside from the fact that Wakefield relied upon no more than a dozen hand picked children as his sample as opposed to hundreds of cases a real scientific study would have used, as it turns out his paper was based upon blatant fraud including the manipulation of patient data and cross-contamination of samples.

We should thank Mr. Wakefield however as he is credited with driving the vaccination rates in the UK down from 93% to around 75% and as a result the measles were actually declared to be an epidemic again in the UK.  This in turned resulted in countless people contracting the measles and in some cases it actually resulted in death, so be sure and mail a thank-you card to Wakefield for his great job (sarcasm intended).

Have I mentioned that not a single scientist has been able to replicate Wakefield's original findings?  Yea... that seems rather important when you try to suggest something is peer reviewed (the Wakefield study was not), but it does explain why so many of the original authors involved with Wakefield's paper later pulled their names from it.  Funny how not a single one of the "doctors" associated with the anti-vaxer movement has been able to replicate Wakefield's original findings even though they continue to profess his original work was sound - but that seems to be status quo for the antivax movement... make accusations but don't bother to back them up with evidence or any real science.

So with all of this said, we can clearly see the results when people decide to stop vaccinating.  Diseases spread, people suffer, and in some severe cases - people actually die.  So what has happened to the rates of autism during this same period of fear-mongering and vaccination avoidance?  If the anti-vaxers are correct the rates should be dropping due to fewer people being vaccinated, but sadly (and predictably) that hasn't been the case. 

Herd immunity is clearly not a myth and it works when people take responsibility for their health and the health of their families. Unfortunately, due to the desire to prey upon the fear of parents, the media has allowed this fraud to be perpetuated among the entire population which has resulted in many parents skipping the necessary vaccinations.  The good news is science is once again prevailing as more and more parents realize these fears are unfounded and the risks of not vaccinating are far too great to ignore. 

The other good news is the media is finally catching up with science and starting to report on the real facts including how Wakefield has been proven time and time again to be a lying fraud and how throughout all of the research and study which has been directed towards vaccines, none of it has proven any type of a link to autism.  In addition to this, due to the number of outbreaks of diseases that were once under control such as pertussis and measles, intelligent and logical people are discovering that herd immunity is not a myth, but rather an undisputed fact.