006 - Vaccine and Vaccination:--Observations and Bacteriological Investigations

This was another paper concerned with the success rate of vaccination. The author is concerned with refining the material used to vaccinate so that it is as pure as possible; that is, free from foreign and unnecessary entities. At that time, people were developing the field of microbiology, enough that they had named some of the bacteria they had discovered (some of which retain the same names today).

Unfortunately, they hadn't figured out what the microbe responsible for vaccination was. They thought it might be a kind of coccus, but this wasn't consistently associated with vaccine material. (Makes sense; they hadn't yet realized there were infectious particles even smaller than bacteria.)

However, they did know enough to realize that there could be contamination of the material with pathogens, and the author recommends trying to avoid this.

He reports a study he did with a group of vaccination patients, in which some of them washed the spot to be vaccinated and others did not. Those that washed had lower rates of excessive swelling, only 14% compared to 32% of those that did not wash. Makes sense.

Most importantly, the author speculates that, at least in some cases, ignorant vaccinators mistook the signs of a bacterial infection for the signs that the vaccination was working (i.e. vaccine disease), and so they thought a patient had been effectively vaccinated when actually they were just infected with bacteria. Then when smallpox came along, of course they weren't protected. Hard to know how much of an effect that might have had, but it seems plausible.

Citation: Paquin, P. Vaccine and Vaccination:--Observations and Bacteriological Investigations. Public Health Pap Rep 17, 171–179 (1891).