Update 1. Added more information about the power of the herd immunity written by Tara Haelle.
One of the most recent and important vaccines added to the current schedule of immunization is the rotavirus vaccine, introduced in the USA in 2007. Before the introduction of the vaccine, rotavirus was the most common cause of severe gastroenteritis in US children under 5 years old. Each year, rotavirus caused an estimated 20 to 60 deaths, 55,000 to 70,000 hospitalizations, and nearly half a million non-emergency visits to healthcare facilities.
A study, recently published the Pediatrics journal, concluded that, after the rotavirus vaccines was introduced, the numbers of diarrhea-related illness in US children dropped significantly. Moreover, probably as a result of herd immunity (where transmission through a population is inhibited by individual who are immune to the disease), the study found that the rate of hospitalizations related to the virus dropped substantially in both vaccinated and unvaccinated children.
The research examined health insurance data from across the USA (except for Medicaid, and a few states that don’t report data) for children under 5 years, cross tabulating various gastrointestinal illnesses with hospitalizations and other medical care. It also compared the same information to the vaccination status of those children. Finally, they gathered data about these illnesses from 2001 through 2006 (before the vaccine was introduced) and 2007-11, to compare hospitalization and other medical facility encounters between the pre- and post-vaccine groups.
The researchers determined the following:
- They ascertained that 58% of the children in the study had been vaccinated against all five strains of rotavirus by the end of 2010, three years after introduction.
- They determined that rotavirus infection hospitalizations were reduced by 75% in 2007-08 (after the vaccine was introduced) compared to 2001-2006. This data was irrespective of vaccination status, just that the overall population exhibited a reduction in the hospitalization rate.
- Compared to the average rotavirus rate in 2001-06, the incidence was 60% lower in 2008-09, 94% lower in 2009-10, and 80% lower in 2010-11. Again, this reduction in rate was irrespective of immunization status.
The data support that, generally, the population of under 5 year old children that required hospitalization from rotavirus had dropped significantly after the introduction of the rotavirus vaccine. Again, there appears to be a substantial herd immunity against rotavirus.
However, the comparisons between vaccinated and unvaccinated children was even more dramatic.
- Children who had received the rotavirus vaccine had 92% lower rotavirus associated hospitalization rate than unvaccinated kids.
- Vaccinated children had 55% fewer diarrhea associated hospitalizations than unvaccinated ones.
- Vaccinated children had 31% fewer diarrhea associated emergency department visits.
Setting aside the suffering to the child and parents, this has a huge economic benefit. The reduction in hospitalizations via vaccination has saved the country over US$83 million in direct medical costs in just 4 years. This is money saved from insurance companies, hospital charge-offs or family savings. Again, as I’ve said many times, Big Pharma makes more money when someone is in a hospital than they would ever receive from a single vaccine.
One of the most amusing tropes of the antivaccination cult is that somehow better sanitation eliminated vaccine preventable diseases (despite some diseases having nothing to do with sanitation). Of course here is a disease, rotavirus, that is transmitted through fecal material, and is one that improved sanitations should have theoretically eliminated. Except, 500,000 kids got sick from rotavirus, a number that has nearly been reduced by nearly 450,000 by 2011. Think about that. Nearly 450,000 children are not getting sick enough to see a physician or emergency room. And unless I’m missing some news report somewhere, there wasn’t a sudden upgrade in the sanitation infrastructure in the USA in 2007. But please, if there is, leave a comment for me, and I’ll rewrite this article!
Put simply, fewer kids needed to be hospitalized for rotavirus EVEN IF they didn’t get the vaccine. How did that happen? Well, it wasn’t sanitation, folks. And no other major changes occurred between the five years before the vaccine and the several years after the vaccine except… the vaccine.
When enough kids were getting the vaccine, which was obviously working since hospitalizations among vaccinated kids decreased so sharply, it prevented the virus from spreading throughout the population. Vaccinated kids who weren’t getting rotavirus because they were protected ALSO weren’t passing it along to other kids, vaccinated and unvaccinated.
The kids who were unvaccinated benefited from those who got the vaccine. Meanwhile, however, those who were unvaccinated? They were the ones more likely to contract rotavirus… and therefore to pass it along to other kids.
Put simply: vaccinated kids were protecting themselves AND others. Unvaccinated kids were at risk AND putting other kids at risk.
So there you go. The vaccine reduced hospitalizations. It built a strong herd effect. The authors of the article concluded that, “our findings demonstrate the substantial and sustained decline in diarrhea-associated health care utilization and related costs in US children after rotavirus vaccine implementation.” And they provided a boatload of evidence to support that.
In the future, if you hear the trope that there is no herd immunity. How about showing them this article!
- Leshem E, Moritz RE, Curns, AT, Zhou F, Tate JE, Lopman BA, Parashar UD. Rotavirus Vaccines and Health Care Utilization for Diarrhea in the United States (2007–2011). Pediatrics. 2014 July;134(1). doi: 10.1542/peds.2013-3849)
- Malek MA, Curns AT, Holman RC, Fischer TK, Bresee JS, Glass RI, Steiner CA, Parashar UD. Diarrhea- and rotavirus-associated hospitalizations among children less than 5 years of age: United States, 1997 and 2000. Pediatrics. 2006 Jun;117(6):1887-92. PubMed PMID: 16740827.