– Which horses can be vaccinated?

All horses from 5 months.

Vaccination is highly recommended for:
  • Horses before competition, sales or possible exposure events.
  • Horses in an area with known outbreaks of strangles

The safety of the product has not yet been tested in pregnant mares and breeding stallions.

– Can I combine Strangvac with other vaccines?

A decision to use Strangvac before or after any other veterinary product should be made on a case-by-case basis

– Should I vaccinate in an outbreak situation?

Not yet tested.

Some guidelines:

Horses with clinical signs and those in contact should not be vaccinated Vaccinated horses that have not been in contact with cases
Last dose >2 months: booster dose will maximize immunity
Last dose <2 months: no booster required

Unvaccinated horses

Start primary course: partial protection from 2 weeks after 2nd dose.

– Should I vaccinate young, old or non-competition horses?

Young and old horses are at highest risk of severe disease if they become infected with S. equi. Vaccination protects these susceptible horses from potential introductions of S. equi. Vaccination raises herd immunity, protecting all horses on the farm. Revaccinate every 6 months if not high risk to maintain memory response.

– Can a vaccinated horse become infected?

Vaccination prevents strangles in up to 94% of horses and reduces the onset and severity of signs (Robinson et al., 2020, Vaccine).

Some vaccinated horses may still become infected because:

  • High level of exposure to S. equi
  • Higher natural susceptibility

Increasing the number of vaccinated horses on a farm can achieve herd immunity:

  • Minimizes transmission and exposure of vaccinated horses
– For how long will my horse be protected from strangles?

Strangvac is a new vaccine and there is limited information on the length of protection. Vaccinated horses are known to be protected from challenge for 2 months after the 2nd dose (Robinson et al., 2020, Vaccine). Vaccinated horses have antibody responses that neutralize an important S. equi protein for 6 months after the 2nd dose (Righetti et al., submitted) Vaccinated horses have an immune memory for 12 months after the 2nd dose, which can be activated by another dose of Strangvac (Robinson et al., 2020, Vaccine) *1.

– Will my vaccinated horse test positive for strangles?

NO: Strangvac does not contain live S. equi cells. Vaccinated horses will not test culture positive unless infected with Strep. equi.

NO: Strangvac does not contain S. equi DNA. Vaccinated horses will not test PCR positive unless infected with Strep. Equi.

NO: Strangvac does not contain the proteins used in the strangles blood test. Vaccinated horses will not test seropositive unless they have been exposed to Strep. equi.

– What kind of adverse events can I expect?

Fever:

A transient rise in body temperature of up to 2.6 °C may occur for one to five days post-vaccination.

Injection site:

Transient local tissue reactions characterized by heat, pain and swelling of up to 8 cm diameter may occur for one to five days post-vaccination.

Ocular:

An ocular discharge may occur for one to five days post-vaccination.

Loss of appetite and demeanour changes:

Loss of appetite and demeanour changes may occur for one day post-vaccination.

– Will Strangvac protect against different variants?

Strangvac is based on the most prevalent variant of S. equi in Europe, BAPS2 . 456 of 457 (99.8% ) isolates of the dominant ST-151 variant were identical to Strangvac at 1,579 of 1,580 amino acids in Strangvac (remaining isolate also had a truncated CNE antigen)

Strangvac was tested with, and shown to protect against, the second most prevalent variant of S. equi in Europe, BAPS5 = heterologous challenge All 137 BAPS5 isolates shared 1,579 of the 1,580 amino acids of Strangvac

Do you have any questions?

Pleace donat hesitate to ask if you have additional questions: strangvacfragor@kvarka.se