Vaccines Vs Pneumonia

One of the linchpins of the anti-vaccine movement is the attempt to muddy the issue with regard to vaccine efficacy. From this point various others follow; if vaccines are ineffective then large risks need not be shown – any risk at all makes being vaccinated an unwise choice. If vaccines do not perform their role then “forcing” people to vaccinate their children is unwarranted.

Lucky for them many of the diseases vaccinated against had the debut of their vaccine quite some time ago which makes it easier to cloud the issue as to causation: perhaps the disease was waning naturally, perhaps it was improved sanitation etc.

Lucky for us vaccine development continues and new vaccines get evaluated down the line to determine effectiveness. This gives us a more recent look how vaccines work and their impact on the population that is not as susceptible to these tactics.

For example, pneumonia is a risk for young children and hospitalisations in the US prior to 2000 hovered around the 1,200 per 100,000 mark. In  2000 a pneumonia vaccine was introduced into the vaccine schedule which targeted 7 of the 90 odd bacterial strains that cause the disease. Recently a study was published looking at the effect of the vaccine on incidence of hospitalisations. In particular the researchers were looking to see if the initial drop in hospitalisations seen in 2000 was holding steady considering the other strains that could fill the gap. They also looked at incidence of pneumonia hospitalisation in age groups other than infants (classed as <2 yrs old) to see if the vaccine was having any effects outside of the nominal target population.

I’m not sure if this expanded scope is normal for this sort of study but I gather that the older population tends to contract the disease from the young family members so this sort of cross population effect at least has a plausible mechanism in this case.

So what was found and why did I bring anti-vaccinationists into this?

Well, first off as was hinted above there was a significant drop in infant hospitalisations in 2000 (the year the vaccine was widely introduced) which continued to the end of the study period in 2009, as shown in this graph:

Oops, alt text here: you should really be seeing a picture. Sorry.

Incidence of Hospitalisation due to Pneumonia per year

In other words, the vaccine is doing it’s job. It’s hard to argue that there was a significant change in sanitation or general practice between 1999 and 2000 to account for the dramatic and sustained drop as seen. I would like to have seen the incidence prior to 1997 extended further in order to see what the trend for the previous 10 years was. However given that the purpose of the paper was routine surveillance, not to refute anti-vaccine proponents, that’s probably a bit much for me to ask. This 2004 study suggests that childhood incidence of pneumonia is around 3,500 cases per 100,000 (~35 per 1,000 as noted in the paper, adjusted here to give the same units as the current study) but does not specify how many of these would have required hospitalisation.

Secondly the study also found a significant drop in hospitalisations for older people as shown in this graph:

Alt text again, you should really get that looked at.

Pneumonia hospitalisations across age groups

So you don’t even need to receive the vaccine directly to get a benefit from it. That’s already well known but it’s nice to have an instance graphed out like this.

As I started this article, if you can throw doubt on the effectiveness of vaccines then arguing follow up points becomes much easier. A corollary to this is that if people are unaware of the facts around vaccine efficacy they will be unable to counter the miss-information and will either be persuaded by it or fail to effectively argue with those who have been already persuaded.

With this in mind I offer the above as further ammunition for those who come up against anti-vaccine arguments at home, at work or as you potter around the wilds of the internet.Enhanced by Zemanta

Previous Articles on the topic of vaccines:

IAS Complaint Part 1

IAS Complaint Part 2

IAS Complaint Part 3

IAS Complaint Part 4

Defending The Term “Anti-Vaccine”

The Legitimate Risks of Vaccines

  1. It’s a shame that many will not believe vaccines are good for us purely because of a friend of a cousins brother told them otherwise.

    Here in Australia we have a group called the Australian Vaccination Network, reading that title you would assume that the group promotes healthy debate whilst shinning light on the facts. However they are purely anti-vaccine, and will delete posts and ban any user who tries to refute their claims.

    The problem is that whilst there are conspiracy nut groups out there like that, then people will always get confused as to which way is right. A lot of the time Medical Professionals will not bother to argue about a point that they have proved a dozen times, therefore seemingly giving false weight to the claims of nut jobs.

    Another thing it comes down to is understanding the ingredients contained within, and understanding that whilst something may be toxic/fatal to you at ‘x’ amount, it may prove quite the opposite at ‘z’ amount.

    • Sorry, got carried away and forgot to thank you once again for an unbiased article. Keep up the good work.

      • What post are you reading? :).
        Thanks, always nice to get positive comments.

        You’re right about real doctors/scientists not bothering to keep fighting the miss-information. It’s understandable but still disappointing.

    • ole Blake
    • July 29th, 2013

    It stands to reason that vaccines work, for most people. However there are those whose susceptibility have contracted the disease that the vaccines were to prevent. Rare indeed, it does happen, from this rare occurrence come doubt and misconceptions, thereby creating anti-vaccine groups and followers mainly because lots of folks do little if any research to learn the truth. Few can refute that polio vaccine stopped an epidemic both in Europe and the US. Smallpox also proved to be an effective vaccine.

    • Its true that vaccines are not 100% effective. No-one claims they are of course, but I think you might be surprised what people would deny when it comes to the efficacy of immunisation.

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