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Q& A

Clostridium perfringens Type A:


answers to frequently asked questions

Clostridium perfringens Type A is an emerging disease that’s being reported with increasing
frequency by diagnostic laboratories. In response to the need for a vaccine, Novartis Animal
Health US, Inc. created the first-ever conditionally licensed C. perfringens Type A vaccine for
cattle – Clostridium Perfringens Type A Toxoid. Following are answers to some of the most
frequently asked questions about this disease and this new preventative option.

Q. Are there different types of C. perfringens?


Product highlights
A. Yes, there are five types of C. perfringens (A, B,
C, D and E), which are identified by the main
types of toxins they produce (alpha, beta, • Shown in Colorado State
epsilon and iota). All toxigenic types make University research to increase
alpha toxin. However, C. perfringens Type A is anti-alpha toxin antibody in
the only one that makes only alpha toxin. C. cows, as well as increase levels
perfringens Type A is a very versatile pathogen. in their colostrum-fed calves2
It’s ubiquitous in nature. Some forms of C. • Shown to have minimal effect
perfringens are found in all healthy livestock. on milk production3
• Only conditionally licensed C.
Q. Why is C. perfringens Type A of concern? perfringens Type A vaccine for cattle
A. C. perfringens Type A is a strain of bacteria that • Field studies demonstrate efficacy and
can rapidly produce potent toxins, primarily product safety
alpha toxin. These organisms make molecules
that can attack host tissues and cause cells to levels of alpha toxoid. Clostridium Perfringens
release their contents and nutrients, which C. Type A Toxoid is based on an isolate that is a
perfringens needs to reproduce. When changes prolific producer of alpha toxin, and uses a
are made in management, feeding or genetics, unique manufacturing process to inactivate
a favorable growth environment in the gut may the toxin that maintains a high level of toxoid
result in overgrowth and production of these in the product. Thus, it stimulates a specific
potent toxins. Alpha toxin is thought to be immune response against the alpha toxin
associated with a number of potentially deadly of C. perfringens to neutralize the toxins.
gastrointestinal diseases and is also commonly
isolated in calves in cases where abomasal Q. What do you mean by “conditionally licensed?”
ulcers and abomasal hemorrhage are found. A. Conditional licenses are a mechanism that the
USDA has to provide tools in the management
Q. What about beta 2 toxin and enterotoxin? of emerging diseases. In order to provide pro-
A. These toxins can be found in some isolates ducers and veterinarians with a product that has
of C. perfringens Type A. However, literature a reasonable expectation of being a help to fight
suggests that these two toxins are not very these diseases, USDA will issue a conditional
important when it comes to cattle.1 license when a manufacturer demonstrates that
their product is safe and that data demonstrates
Q. Don’t typical seven-way or Type C and D that the product can be reasonably expected to
vaccines provide Type A protection? be beneficial in disease control efforts.
A. Commercial clostridial vaccines do not demon-
strate significant alpha toxin antigenic activity. Q. What is known about this product’s efficacy?
This is because they are manufactured in a A. A. To receive a USDA conditional license,
manner that does not generate any significant Clostridium Perfringens Type A Toxoid had
to pass a USDA standardized test. This test A. Clostridium Perfringens Type A Toxoid
required a reasonable expectation of efficacy be contains an isolate from a real-world
demonstrated by the development of a serum hemorrhagic bowel syndrome (HBS) case that
antibody concentration of at least 4 international produced a high level of alpha toxin. By using
antitoxin units per mL in at least 80 percent of this isolate and carefully controlling the culture
vaccinated animals that were seronegative prior and harvest conditions, Novartis was able to
to vaccination. Clostridium Perfringens Type A maximize the amount of alpha antitoxin in the
Toxoid produced a serum antibody concentra- vaccine. As a result, the conditionally licensed
tion of 8 international antitoxin units per mL product provides a more consistent vaccine
in 89 percent of vaccinated calves that were versus most custom products.
seronegative prior to vaccination. This means
the level of circulating antitoxin in the blood Q. What is the ideal timing for administering
was double that required by the USDA. this product in dairy cows? What about
In a Colorado State University study, tests beef cows?
were conducted to determine if vaccinating A. By vaccinating during the dry period or shortly
pregnant cows and heifers with Clostridium after calving, the cow receives maximum
Perfringens Type A Toxoid affected the serum protection in the first part of lactation. Beef
neutralizing antibody titer to alpha toxin in the cows can be vaccinated at pre-calving or
colostrum-fed calves of the vaccinated dams.2 preg-check time.
Results found that the vaccine administered
during the dry period led to increased anti- Q. What about its use in calves?
alpha toxin antibody in cows, as well as A. The best way to protect calves is by vaccinating
increased levels in their colostrum-fed calves. the pregnant cow prior to calving to provide the
calf with passive immunity via colostrum. This
Q. What effect does vaccination with Clostridium product can be safely injected subcutaneously
Perfringens Type A Toxoid have on milk production? into calves as young as one month of age.
A. In a milk production trial with Clostridium
Perfringens Type A Toxoid, researchers took Q. Is this product safe for use in all classes
milk weights for seven days prior to vaccination of cattle?
and 31 days post-vaccination. Data on 92 A. Yes, when used as directed, Clostridium
vaccinated animals and 96 control animals Perfringens Type A Toxoid has been proven
were used in the analysis. Results showed no safe according to vaccine standards in trials
significant difference (p=0.79) between with 867 dairy and beef cattle of various ages
treatment groups.3 and breeds, both open and pregnant, and
calves as young as one month of age. The
Q. Why would one select Clostridium Perfringens product should only be used in cattle.
Type A Toxoid over a custom Type A vaccine?
Q. What other things should I consider when
trying to manage disease syndromes
associated with Type A?
A. The best way to avoid problems with
C. perfringens Type A is prevention. In addition
to vaccination, management strategies to
consider include:
• Evaluate and correct nutritional factors that
may predispose cows and calves to
gastrointestinal diseases
• Test silage to verify its quality
• Keep feed pushed up and remove leftover
feed from the bunk daily
• Identify and correct problems that may
lower cows’ disease resistance

1. Bueschel DM, et al. Prevalence of cpb2, encoding beta2 toxin, in Clostridium perfringens Type A alpha toxin in dairy calves fed colostrum
Clostridium perfringens field isolates: correlation of genotype with pheno- from immunized dams. Paper presented at Annual Meeting of American
type. Vet Microbiol. 2003;94(2):121-9. Association of Bovine Practitioners. 2006. Saint Paul, Minnesota.
2. Van Metre D, et. al. Passive transfer of neutralizing antibodies to 3. Data on file, Novartis Animal Health US, Inc.

© 2008 Novartis Animal Health US, Inc. www.livestock.novartis.com


Printed in the USA 4517077R, FEB08

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