The Rural Voice, 2001-06, Page 30After a long hard
winter the heat is
finally on. but that
can be bad news for the
effectiveness of your
vaccines unless you take
special precautions.
Dr. Neil Anderson.
veterinary science at
OMAFRA. Fergus office
and Tamara Keeley a
research assistant at
Guelph. studied the effect
temperature could have on
vaccines in storage on the
farm and found proper
storage can make the
difference between an
effective vaccine and one
that is wasted.
Both heating and
freezing render vaccines
useless and precautionary
statements on labels
emphasize critical
temperatures for vaccine
storage between 2-7
degrees C., Anderson told
the Recent Developments
in Pork conference in
Shakespeare last winter.
Freezing is a greater
hazard for killed vaccines
than modified virus
vaccines. However.
Anderson warned. several
modified live virus
vaccines use a killed
component as a diluent.
These combination
vaccines must be handled
as a killed vaccine.
"Check the labels on
most veterinary vaccines
and you will find the
same, or very similar
'precautions'. For
simplicity, manufacturers
of veterinary vaccines
instruct us to handle all
veterinary vaccines the
same way."
As part of their
research, Anderson and
Keeley looked both at the
dependability of
refrigerators and of
coolers used for
transporting vaccines.
They recorded
temperature cycles for
four different
26 THE RURAL VOICE
Cool it, man
(and woman)
It takes only a few minutes of too
much warmth or too much cold to
destroy the effectiveness of vaccines
so keep them in a fridge or cooler
By Keith Roulston
1
refrigerators: an office
fridge, a house fridge, a
lab fridge and a porch
fridge (commonly known
as a beer fridge). The
refrigerators were 2, 19,
25 and 30 years old. Both
shelf temperatures and
temperatures on door
shelves were recorded.
What all the machines
had in common was the
cyclic fluctuation of
temperature. The office,
lab andporch refrigerators
had a range of
approximately three
degrees from coldest to
warmest. The house fridge
had a range one degree
colder on the shelf than on
the door. On two of the
fridges the shelf
temperature actually fell
below the freezing mark
which would damage the
vaccine.
Within refrigerators the
temperature can vary
greatly depending on
which shelf or where on
the shelf, the vaccine is
stored. Tests on the office
fridge showed the back of
the shelf remained below
freezing for an entire day
no matter what the cycle
of the temperature. Cold
spots are poor locations
for vaccine storage, the
researchers say.
Anderson and Keeley
also found the temperature
could rise to 10 degrees C
if the fridge door was kept
open for 1.5 minutes. For
that reason, they
recommend vaccines not
be kept in a refrigerator
that's being opened
frequently, such as one
where lunches or drinks
are stored.
The researchers
recommend making your
refrigerator vaccine
friendly by giving it a
regular checkup. "Just
because you hear it
running doesn't mean it's
working properly,"
Anderson said. Take the
temperature inside the
fridge several times over
several days and keep
records. Expect cyclic
fluctuations in
temperature. Overall your
refrigerator must maintain
a temperature of 2-7
degree C to protect you
investment in vaccines. If
it doesn't, call for service.
If you take a vaccine or
medicine out of the fridge.
it can quickly warm up
and lose its potency.
Anderson and Keeley
found. They tested how
quickly 50 and 100 ml
vials of water warmed up
when taken from the
fridge and left at room
temperature. The 50 ml
vial warmed to 10 degrees
C in just 20 minutes and
to room temperature in
about an hour. The 100 ml
vial warmed to 10 C in 35
minutes and room
temperature in an hour
and a half.
While the researchers
admit water samples may
warm faster or slower than
actual medicines, the
lesson4 is to use
medications promptly and
return them to the
refrigerator quickly, they
say.
"Our advice: learn
from the coffee shop.
Freshness counts,"
Anderson said. "At our
local coffee shop, the time
of brewing is written on
each pot of coffee. If it's
not sold within the
"freshly brewed" time
frame, the coffee goes
down the sink drain.
"This elegant coffee
shop monitoring system
should be tried for our
vaccines," he said. "The
next time you remove
vaccine from your
refrigerator, write the time
on the medicine bottle.
When it is empty, or
returned to the
refrigerator, note the
elapsed time. Did you
1