Many
Factors to Consider When Selecting a Vaccine
“Implementing
a vaccination protocol is part of an overall strategy meant to lead directly to
healthy cows and financially profitable dairies,” said Douglas Braun, DVM,
senior veterinarian for
When
looking at the many vaccines on the market, and sorting through the many
competitive products and facts, Braun recommends that both veterinarians and
producers turn toward an unbiased source to help make the purchase
decision—the U.S. Department of Agriculture (USDA).
The
decision about which type of label claim a vaccine will be granted is based on
an evaluation by the Center for Veterinary Biologicals, which is part of the
Animal and Plant Inspection Service of the USDA. The USDA may grant one of five
possible label claims. They include:
1.
Prevention of infection: Prevents all colonization or replication of
challenge organism.
2.
Prevention of disease: Highly effective in preventing clinical disease.
3.
Aid in disease prevention: Aids in preventing disease by a clinically
significant amount.
4.
Aid in disease control: Aids in reduction of disease severity, duration
or onset.
5.
Other claims: Products with beneficial effects other than direct disease
control.
The
best way to find out what label indication applies to a particular vaccine is to
read the label closely. The approved label for a given vaccine helps us
understand the expected performance of the product. Most vaccines on the market
have the “aid in disease prevention” claim. Rarely, however, will a vaccine
satisfy the requirements to receive the more robust “prevention of
infection” or “prevention of disease” label indications. Always read the
label closely before making a decision about which product best fits the needs
of your dairy herd.
Beyond
looking for the label claim when choosing a vaccine, Braun recommends getting
more information about the vaccine’s duration of immunity (DOI). Vaccines have
traditionally been labeled for repeat dosing within 12 months, or administration
of a booster within a certain time period without any clear evidence supporting
the expectation that the vaccine was actually effective for that given length of
time. Today, however, more manufacturers are providing the USDA with challenge
data to help support their DOI claim.
“In
the past, there was generally little information to verify that the vaccine
actually protected cows for 12 months,” Braun explained. “We’re now
starting to see claims reading ‘12 month duration of immunity has been
demonstrated’ rather than just ‘revaccinate annually.’ As veterinarians
and producers build their young stock risk management strategies and incorporate
those strategies into maintaining herd immunity in the mature population, having
assurance the vaccine is providing protective immunity for at least the stated
DOI is reassuring.”
In
addition to USDA label claims and the DOI data, producers should ask
manufacturers for challenge trial data. This data—gathered when trials are
conducted looking at the efficacy of a product—can tell a producer how a
vaccine should work on their farm.
“These
challenge trials help us understand what we can expect in real life from a
vaccine,” Braun said. “I would encourage producers and veterinarians to ask
for challenge trial information from the manufacturers. Ask for everything that
is out there. It is helpful in making decisions on what products will be most
useful.”
Work
together with your herd veterinarian to develop a vaccination protocol that
builds the herd immunity you are looking to achieve. Tactical implementation of
the vaccination protocol needs to consider many factors; age, housing, grouping
and stage of gestation are all critical to the success of building herd immunity
and make it clear why using the teamwork approach is so important to achieve the
desired outcome. “Herd immunity comes from implementing a well-thought-out
plan, not just sticking the calves or cows with a needle and a vaccine,”
according to Braun.
Braun
recommends producers review their herd immunity strategy, vaccination protocol
and the label claims on any products they are currently using with their
veterinarian to be sure they are protecting their herds from diseases of
concern.
For
more information on duration of immunity, go to www.bovi-shieldgold.com.
The
Pfizer
Inc. (NYSE: PFE), the world’s largest research-based pharmaceutical company,
is a world leader in discovering and developing innovative animal vaccines and
prescription medicines.
###