(Part two of two)
In response to several expressions of interest, here is some background
information on the distemper vaccine survey, including survey method, data
aggregation strategy, assumptions, criteria, and important "cuts" of the
aggregated raw data from the questionnaires. The percentage breakdowns may
be found in a separate posting, titled "Vaccine survey report," as
disseminated in the October 93 Independent Voice.
The survey form was distributed nationwide in early 1993 to shelters and
clubs through their newsletters, to veterinarians and private ferret
enthusiasts, and was posted online on several different boards (inter alia
GEnie, CIS Pet Forum, and FML). Respondents were asked to specify the
brand or brands of vaccine used; the number of ferrets on which each
vaccine was used; the month and year; whether vaccine was administered by
DVM or non-DVM; where on the body the ferret was injected; whether vaccine
was warmed to room temperature before being injected; whether the sterile
solution packaged with the vaccine was used; and what percent of animals
reacted in particular ways.
In addition to the "other problems" option, choices offered were no
reaction, stings, screams, lethargy, vomiting, and seizures. Respondents
were also asked to provide the lot number & date on the vaccines and to
state whether the distemper vaccine was given in conjunction with a rabies
vaccination.
Copies of the raw questionnaire responses were sent to Dr. Starling at USDA
and to Roger Brady at United. For our own compilation of the responses, we
grouped and categorized reactions as minor, medium, or severe. Where a
single vaccine administration was reported as having elicited more than one
reaction (e.g. stinging and convulsions), only the most severe reaction was
counted, to avoid the distortion of duplications. If no specific vaccine
was named, the entire response was disregarded, and if the number of
administrations was not reported, it was arbitrarily counted as "1". Then
the data was analyzed to see how the picture changed depending on vaccine
administrator, injection site, simultaneous administration of rabies
vaccine, etc. The most meaningful variables proved to be the injection
site, administrator (vet or not), and brand. Only results for injection of
Fromm-D and Fervac-D were tabulated, because the number of injections of
other vaccines reported (a few dozen) was too small to make statistically
significant inferences.
To preclude any "repeat voting," respondents were required to identify
themselves (name, address, telephone), and several respondents were called
to verify or clarify the information they provided. Questionnaires
returned without identification of respondent were discarded.
The GCFA shelter provided the numerically largest sample of data (several
hundred injections), but unfortunately their questionnaire was returned too
close to press time to be tabulated in our report and is therefore not
reflected in the figures below. Had the GCFA figures been used, they would
have increased the percentage disparities in reactions between Fervac-D and
Fromm-D but not materially affected the results respecting injection
administrator or injection site.
For the statistically inclined, here are the aggregated raw data on which
our report of survey responses was based. (Apologies if the columns turn
out not quite properly aligned.)
[I took the liberty of fixing them.]
I. Responses by reaction: (listed in order of increasing severity; only
most serious reaction counted)
Total Fervac-D Fromm-D
Sample size: 1372 508 864
No reaction: 1173 362 811
Stinging: 161 120 41
Screaming: 13 12 1
Lethargy: 19 10 9
Vomiting 3 1 2
Seiz/Coma: 2 2 0
Death: 1 1 0
II. DVM-administered only:
Total Fervac-D Fromm-D
Sample size: 258 160 98
No reaction: 246 150 96
Stinging: 6 6 0
Screaming: 2 2 0
Lethargy: 2 1 1
Vomiting: 1 0 1
Seiz/Coma: 0 0 0
Death: 1 1 0
III. Self-administered only:
Total Fervac-D Fromm-D
Sample size: 1114 348 766
No reaction: 927 212 715
Stinging: 155 114 41
Screaming: 11 10 1
Lethargy: 17 9 8
Vomiting: 2 1 1
Seiz/Coma: 2 2 0
Death: 0 0 0
IV. Injection at shoulder or neck only:
Total Fervac-D Fromm-D
Sample size: 986 258 728
No reaction: 901 189 712
Stinging: 48 43 5
Screaming: 13 12 1
Lethargy: 19 10 9
Vomiting: 2 1 1
Seiz/Coma: 2 2 0
Death: 1 1 0
V. Injection at hip, rump, or leg:
Total Fervac-D Fromm-D
Sample size: 386 250 136
No reaction: 272 173 99
Stinging: 113 77 36
Screaming: 0 0 0
Lethargy: 0 0 0
Vomiting: 1 0 1
Seiz/Coma: 0 0 0
Death: 0 0 0
For purposes of grouping reactions into minor, medium, and severe, we
treated stinging as minor, screaming and lethargy as medium, and vomiting
and seizures or coma as severe.
--Ann Davis.
[Posted in FML issue 0719]
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