In addition to its high zoonotic impact, brucellosis is a major cause of abortion and infertility in cattle, which results in significant economic losses for farmers. Vaccination is the most practical and effective tool to reduce the incidence of brucellosis in endemic areas
B19 CZV OCULAR is a freeze-dried suspension of the live Brucella abortus strain 19 vaccine (also called B19 strain) in smooth phase for the immunization of cattle against brucellosis induced either by B. abortus or B. melitensis.
Manufactured in compliance with OIE and EU standards, B19 CZV OCULAR is the first anti-brucellosis vaccine registered for conjunctival administration to cattle.
Moreover, B19 CZV OCULAR is safe enough even in adult cows, being thus the best prophylactic tool to control the disease in endemic areas through mass vaccination programs. Moreover, when applied in young replacement heifers and combined with suitable diagnostic methods, can be used successfully in test and slaughter based eradication programs.
B19 CZV OCULAR combines both a perfect dissolution of the freeze-dried
content with a suitable solvent (stained with Patent Blue V to allow a
better assessment of the proper application in the conjunctival mucosa)
and the high dosage precision of the dropper, allowing an easy vaccine
application as a single drop placed on the corneal surface
At difference of that happening with the classical B19 subcutaneous vaccine, B19 CZV OCULAR induces a very weak and short-lasting serological response which does not interfere at long term when applied exclusively in young replacement heifers of 3-4 months of age. In absence of secondary antigenic contacts, most vaccinated heifers became negative in both RBT and CFT brucellosis tests between 6 and 8 months after vaccination. Thus, this weak antibody response minimizes or even abrogates the potential interference in the conventional serological tests used in test and slaughter eradication programs.
When the objective is reducing brucellosis prevalence to a minimum, B19 CZV OCULAR is the vaccine of choice for mass vaccination since:
A single dose confers suitable immunity in a similar way to that induced by the classical subcutaneous vaccine.
With the exception of bulls (in which safety has not been fully assessed), it can be used in both young and adult animals including pregnant and lactating cows causing minimal side effects (less than 3% of induced abortions and shedding of the vaccine strain in milk).
A program based in the conjunctival vaccination of the whole population (with the exception of bulls) being repeated every two years for at least one animal generation (5 to 8 years) is the most practical, economical and effective strategy to control the disease. As an alternative, the vaccination of the whole population the first year and then applying the exclusive vaccination of young replacement heifers the ensuing years will also control the disease, reducing the prevalence to a minimum compatible with the further application of a testing and slaughtering eradication program.
Blasco and Molina-Flores, 2011: Control and Eradication of Brucella melitensis Infection in Sheep and Goats. Vet Clin Food Anim 27: 95–104