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This Week in MicroBiology Class

06 Sep
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Jaundice

Instead of starting our chapter on Eukaryotic micro-organisms / parasites, we spent much of Thursday’s class discussing the second Chapter of ‘Vaccinated’. This chapter digs in and discusses how a number of vaccines were tested in the children of the Willowbrook institution in New York. We talked about how researchers must balance the (sometimes) competing interests of doing the best experiments to answer a question and looking out for the interests of those who can not look after themselves (the children of Willowbrook, in this case).

This chapter looked at the work of several investigators; Most evaluating vaccines, but one (Krugman) was also doing experiments to investigate how Hepatitis was spread. His work included the infection of a number of children with live virus, but no attempt at protecting them from infection.

This is presented as the most condemnable work of the lot as it presented no potential benefit to the children. In saying this we define the principle by which other work was done, ‘does the study do no intentional harm and does it provide at least some potential benefit to the subjects?’

This principle provides a challenge to doing the (scientifically) ideal experiment outlined below.

A basic, direct vaccine test would divide patients into two groups (vaccinated and unvaccinated) and then challenge half of each group with live virus (or whatever the vaccine is to protect against).

Ideal results:

vaccinated –> unchallenged –> 100% healthy

vaccinated –> challenged –> 100% healthy

unvaccinated –> unchallenged –> 100% healthy

unvaccinated –>challenged –> 100% sick

However, this means that the researcher would be knowingly (assume s/he is not blinded) injecting unprotected patients with live virus – an obvious ethical issue.

In looking through some old work done to investigate how hepatitis is spread, there was a mention of work conducted in just such a manner:

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Bellin and Bailet J. Ped 1952

It’s unclear from this reference to a personal communication what, exactly the word ‘volunteer’ means.

I’ll bring up this paper in class the next time we discuss Vaccinated. I have an interesting person connection to it.

Instead of a experimentally controlled challenge, modern vaccine tests (as the other work described in this chapter) use much larger populations chosen because of their ‘at risk’ nature and then we wait and see if there are statistical differences between the infection rates of each group.

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Posted by on September 6, 2013 in Uncategorized

 

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