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**INACTI/VAC^®^ SE4**

When we first started working with Salmonella Enteritidis (SE) years
ago, very little was known by anyone about the infection in poultry. It
was certain, however, that SE was a serious threat to the safety of our
food supply. Since then, Lohmann Animal Health International (LAHI) has
undertaken a massive research effort to understand SE infection in the
field and learn how to control it. We devoted much of our research and
development resources and worked closely with outside researchers,
government agencies and customers to unravel the unknown factors
regarding this organism. Our goal was not to be the first to produce a
licensed SE vaccine. Instead, we wanted to learn as much as possible
about the organism to develop a product that would be safe and provide
the best protection. After years of producing high quality autogenous SE
bacterin, conducting extensive research and collaborating with expert
scientists, we developed **Inacti/Vac SE4.**

SE has been a problem for the layer industry for many years and remains
a serious threat today. Eggs continue to be associated with human SE out
breaks. Since it has been determined that SE cannot be eradicated, it
will continue to be a threat. The USDA SE Pilot Project has found that
50% of tested flocks are positive on environmental sampling. Concerned
producers in Pennsylvania participate a voluntary program that includes
testing eggs from environmentally positive farms. If the eggs are
positive for SE they are diverted to breakout. This practice has been
estimated to prevent over 100,000 SE positive eggs from reaching the
market. In doing so, it has also sent 360 million eggs to breakout and
pasteurization.

**Inacti/Vac SE4** decreases SE colonization of the cecum. Field trials
show that multiple houses remained negative on environmental sampling
with the help of SE vaccination. In contrast, several intermixed houses
with non-vaccinated layers turned positive within 10 weeks of housing.
In controlled studies, we have shown that vaccinating with an SE
bacterin decreases fecal shed, which can help keep a house negative.
Figure 1 shows the results of SE fecal shed after a severe oral
challenge in vaccinated and non-vaccinated birds.

Figure 1.

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height="3.2416666666666667in"}

The vaccinated group sheds SE for the first 24 hours as SE bacteria pass
through the intestinal tract, unable to colonize the protected mucosal
layer. Intestinal culture results confirm that vaccination controls
colonization. At 14 days post challenge, intestinal tract culture
results reveal 100% protection against colonization. In contrast, SE
colonized the intestinal tract of birds in the control group after oral
challenge. Subsequently, SE multiplication in the intestinal tract leads
to increased fecal shed. When this occurs in a flock, the increased
fecal shed allows the house to be seeded down with SE and birds are
continuously exposed to the organism. Beyond decreasing environmental
contamination, protection of the intestinal tract decreases the chance
of eggshell contamination.

SE vaccination also helps decrease internal egg contamination by
protecting the reproductive tract from SE colonization. Figure 2 shows
the protection against reproductive tract colonization following a
severe oral and intramuscular (IM) challenge. **Inacti/Vac SE4**
provides 100% protection following IM challenge with over one million SE
bacteria. Following oral challenge with more than 10 million SE
bacteria, **Inacti/Vac SE4** provides 97% protection. Although this
method of challenge is much more severe than field exposure it does
demonstrate the high level of protection you receive by using
**Inacti/Vac SE4**.

Figure 2.

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LAHI studied phage type cross protection during development of this
bacterin. Our research demonstrated that cross protection exists between
phage types. Independent researchers have confirmed these studies; but
we did not stop there. We conducted many experiments with various single
and multiple isolate vaccines to decide which gives the best protection.
To provide optimum protection, we have incorporated four specific phage
types into **Inacti/Vac SE4**. This combination provides antigenic
diversity to protect your flock from its specific field challenge. The
four phage types are also the most common isolates found in field
samples from our customers. Furthermore, the incorporation of four
isolates provides a large amount of antigen to produce a strong immune
response.

**Inacti/Vac SE4** is designed to aid in the protection of your
operation from producing SE contaminated eggs. Vaccination of
replacement pullets should be used in combination with testing,
cleaning, disinfection, rodent control and biosecurity. A total SE
program is another way to assure that the US food supply is the safest
in the world. It also shows that your company cares about the consumers
of your product. Our years of experience producing high quality
autogenous SE bacterins, conducting extensive research and collaborating
with expert scientists have helped developed **Inacti/Vac SE4**. We are
proud to continue playing a role in lowering this human health risk
associated with SE.