Equilis Prequenza is a vaccine for use in horses. It contains parts (subunits) of three equine influenza (flu) strains (‘A/equine-1/Prague/1/56’, ‘A/equine 2/Newmarket/1/93’ and ‘A/equine-2/Newmarket/2/93’). The vaccine is available as a suspension for injection.

Equilis Prequenza is used to vaccinate horses from six months of age against equine influenza. Equine influenza is a highly contagious disease that is very common in horses but that rarely causes death. The vaccine reduces the signs of equine influenza and the excretion (shedding) of the virus after infection.

The vaccine is given as an injection into a muscle.

Horses should receive a primary vaccination, consisting of two injections given four weeks apart. This should be followed by a third vaccination five months later, and afterwards by yearly revaccinations.

Equilis Prequenza contains fragments (subunits) of the influenza virus against which the vaccine is indicated for. These fragments provoke a protective response of the immune system (the body’s natural defences) but cannot cause the disease.

Vaccines work by ‘teaching’ the immune system how to defend itself against diseases. When the product is given to horses, it helps the animals’ immune system to react more quickly when the animal is naturally exposed to the virus. This helps to protect against equine influenza. The vaccine also contains an ‘adjuvant’ to stimulate a better response.

The safety of Equilis Prequenza was studied in several studies under laboratory and field conditions in a large number of horses, from 2 months of age. It was concluded that the product is well tolerated by horses of different ages. Equilis Prequenza was also studied in pregnant mares. No negative influence on gestation, foaling and offspring of mares was observed after vaccination at different times during pregnancy.

The effectiveness of Equilis Prequenza has been studied in several trials under laboratory and field conditions. Most of the studies used Equilis Prequenza Te, a vaccine that protects against the three equine influenza strains (the same as Equilis Prequenza), as well as tetanus. The main measure of effectiveness was the production of protective levels of antibodies against the influenza components. The studies also compared the clinical signs and virus excretion of a group of vaccinated animals with those of a control group, i.e. which did not receive the vaccine.

The studies showed that Equilis Prequenza is an effective vaccine against equine influenza to reduce clinical signs and virus excretion after infection, in horses from 6 months of age. Horses developed protection two weeks after primary vaccination. The duration of protection was five months after primary vaccination and 12 months after the first revaccination.

Swelling (max. diameter 5 cm) may occur, either as hard or soft swelling. The swelling is expected to decrease within two days. Pain at the injection site can occur occasionally. In some cases fever may occur for one day, and up to three days in exceptional circumstances.

In case of accidental self-injection, seek medical advice immediately and show the package leaflet or the label to the doctor.

The withdrawal period of the product is zero days.

Zero days.

The Committee for Medicinal Products for Veterinary Use (CVMP) concluded that the benefits of Equilis Prequenza exceeded the risks for the immunisation of horses from six months of age against equine influenza to reduce clinical signs and virus excretion after infection. The Committee recommended that Equilis Prequenza should be given a marketing authorisation.

The benefit-risk balance may be found in module 6 of this EPAR.

The European Commission granted a marketing authorisation valid throughout the European Union, for Equilis Prequenza to Intervet International BV on 8 July 2005. Information on the prescription status of this product may be found on the label/outer package.