Frequently Asked Questions Nobilis Salenvac and Nobilis Salenvac T
What is Nobilis
Salenvac and Nobilis Salenvac T?
Nobilis Salenvac T is an inactivated vaccine containing Salmonella
Enteritidis ‘phage type 4 and Salmonella Typhimurium
DT 104.
Nobilis Salenvac contains Salmonella Enteritidis phage type 4.
Is ‘phage
type or DT important in the way the vaccine works?
Intervet simply used the most common types affecting chickens
in Europe. The designation ‘phage type 4’ refers to
the way in which a particular set of bacteriophages attacks the
Salmonella and is used to help researchers find the source
of outbreaks. Definitive Type (DT) is a way of sub-dividing S.
Typhimurium. As far as efficacy is concerned, the vaccine acts
equally well against all strains of S.Enteritidis and S.Typhimurium.
Does Nobilis
Salenvac T cross-protect against any other Salmonella?
Research in the UK shows that Salenvac T gives group protection.
For example S. Typhimurium belongs to Group B and trials
have shown the control of other group B serotypes – notably
S. Agona and S. Heidelberg (international dossier).
What are IRP's?
IRP stands for Iron Regulated Proteins in the outer membrane.
These are special, highly antigenic proteins expressed on the
surface of the Salmonella cell during growth in the bird’s
intestine where there is a shortage of iron. Intervet mimics this
situation when preparing the vaccine and the final vaccine is
almost identical in relation to antigenic composition to the Salmonella
that would challenge the bird. The bird produces antibodies that
are exactly the ones needed to combat this challenge.
For more information see Iron Restriction Technology
What sort of
immunity does Salenvac T give?
Two injections of Salenvac T give an immune response consisting
of Immunoglobulins G (IgG) and M (IgM) as well as cell-mediated
immunity. IgG is also excreted in the bile. This means that Salenvac
T controls the Salmonella challenge in both the intestines
and the organs.
Is immunity
provided by Nobilis Salenvac found in the egg?
Immunoglobulins are concentrated in the egg. For eggs that
will hatch to become broiler chickens, this means that chicks
are protected for at least 21 days against S. Enteritidis
challenge (UK research using Salenvac 1995). In relation to eggs
for human consumption, this means that eggs are very unlikely
to be laid with Salmonella in them. Recent research has
shown that if they are contaminated with S. Enteritidis
after laying, the bacteria cannot grow well and the numbers of
S. Enteritidis remain low in comparison with unvaccinated
control eggs.
How successful
has Nobilis Salenvac been in the UK?
Nobilis Salenvac (S.
Enteritidis only) was launched in 1995 and when used in laying
birds from 1997 to 2001 was responsible for a 63% reduction in
human food poisoning cases from S. Enteritidis. A UK
government organisation (The ACMSF) said Salmonella control
was ‘a real success story’ and attributed much of
this to vaccination. Salenvac was the only available vaccine at
the time.
When should
birds be vaccinated with Nobilis Salenvac or or Nobilis Salenvac T?
The first vaccination is usually at 12 weeks of age
and the second at 16 weeks. Two vaccinations are needed to
give full immunity, and should be at least 4 weeks apart. So
you can use the vaccine at the most practical time. In high risk areas it is possible to give at day old 0,1 ml with a repeated dose 4 weeks later(0,5 ml). Recommended is to give a booster dose at 18 weeks.
Where should Nobilis Salenvac or Nobilis Salenvac T be administered?
Both Nobilis Salenvac and Nobilis Salenvac T should be administered intramuscularly under aseptic circumstances.
What adjuvant
does Nobilis Salenvac T contain?
Alhydrogel – Aluminium Hydroxide Gel. This is a water-soluble
adjuvant that minimizes vaccine reactions and is safer in case of accidental self injection than water in oil Salmonella vaccines.
Why is Nobilis
Salenvac T, as used, more effective than a ‘drinking-water-only’
vaccine?
When a Salmonella vaccine is injected it results in the
production of antibodies which prevent the ovaries being infected.
This avoids vertical transmission of Salmonella through
eggs. Control of vertical transmission is the key to successful
control of S. Enteritidis. Drinking-water-only vaccination
merely causes a local intestinal immunity which controls shedding
of the Salmonella but not vertical transmission by birds
with infected ovaries.
Are there any
other benefits from vaccination with Nobilis Salenvac T?
Trials with Nobilis Salenvac showed that there was an increase
in productivity in broiler breeders following vaccination. In
two trials the number of chicks per vaccinated breeder rose by
2.15 and 1.91 respectively and the cumulative hatchability rose
by 2.64% in one trial.
Is it true that
Nobilis Salenvac or Nobilis Salenvac T adversely affects the birds after vaccination?
Handling and injecting birds with Nobilis Salenvac and Nobilis Salenvac T gives only a minimal vaccine reaction. This means no disruption in growth and onset of production
What other avian
species has Salenvac T been used for?
Salenvac T has been used (off label) in turkeys (2x0.5ml injections 4 weeks
apart), ducks (2x0.5ml injections 4 weeks apart) and pigeons (2x0.1ml
injections 2 weeks apart).
For the use of the vaccine in turkeys
please refer to the following publication Tenk I., Gyorváry
I., Erdei P., Szabó Z., Kostyák Á. and Mátray
D. (2000)
Effect of a vaccine against Salmonella enteritidis (Salenvac)
on salmonella shedding in breeder turkey flocks.
Hungarian Veterinary Journal 122:737-741
See Publications
for english abstract