This study has two parts, both relating to whooping cough vaccination. The first seems like a brief summary of a clinical trial, and the second is an animal trial testing which method of killing pertussis bacteria makes the best vaccine.
Part I
This was more exciting, and thus unfortunately lacking in details. There were 288 vaccinated and 1007 control children, followed by questionnaires to parents and physicians. There were 52 known exposures of controls to disease, and 97 exposures in the vaccinated group. From these exposures, 43 resulted in disease in controls, and 10 in vaccinated. This means 82% infection rate in controls, and 10% in vaccinated, meaning 72% protection from the vaccine. That's pretty good.
Also worth mentioning was that 23 of the 97 vaccinated exposures were intimate, meaning siblings that shared a bed or played together or whatever, but none of these resulted in disease in the vaccinated child.
So pretty good, but lacking in necessary details.
Part II
This was a study in mice using vaccines made of killed bacteria, but killed in different ways: phenol, formalin (formaldehyde), merthiolate (thimerosal), or heat. They tried increasing doses of each in mice before challenging with pertussis to see how many died. They found that phenol-killed vaccine required the lowest dose to start showing protection, followed by heat-killed. The others were worse.
The dose required to show any protection, relative to the weight of the mice, was very high, but this could be explained by the requirement that mice be able to resist a serious bacterial infection (the bacteria are injected into their body cavity), rather than a simple respiratory exposure, so it's probably not comparable to humans, in dose at least.
Reference:
Part I
This was more exciting, and thus unfortunately lacking in details. There were 288 vaccinated and 1007 control children, followed by questionnaires to parents and physicians. There were 52 known exposures of controls to disease, and 97 exposures in the vaccinated group. From these exposures, 43 resulted in disease in controls, and 10 in vaccinated. This means 82% infection rate in controls, and 10% in vaccinated, meaning 72% protection from the vaccine. That's pretty good.
Also worth mentioning was that 23 of the 97 vaccinated exposures were intimate, meaning siblings that shared a bed or played together or whatever, but none of these resulted in disease in the vaccinated child.
So pretty good, but lacking in necessary details.
Part II
This was a study in mice using vaccines made of killed bacteria, but killed in different ways: phenol, formalin (formaldehyde), merthiolate (thimerosal), or heat. They tried increasing doses of each in mice before challenging with pertussis to see how many died. They found that phenol-killed vaccine required the lowest dose to start showing protection, followed by heat-killed. The others were worse.
The dose required to show any protection, relative to the weight of the mice, was very high, but this could be explained by the requirement that mice be able to resist a serious bacterial infection (the bacteria are injected into their body cavity), rather than a simple respiratory exposure, so it's probably not comparable to humans, in dose at least.
Reference:
Silverthorne, N. Active Immunization Against Whooping-Cough. Can Med Assoc J 41, 263–265 (1939).
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