Gumbohatch

Gumbohatch is a vaccine used to protect broiler chickens (reared for meat) against infectious bursal disease (IBD) virus infection caused by a very virulent IBD virus. Virulent means that the virus is capable of producing severe disease.

IBD, also known as Gumboro disease, is a highly contagious (spreads easily) viral infection of young chickens that reduces their immunity (body’s ability to fight disease) and can lead to their death at 3 to 6 weeks of age. Signs of chickens infected with Gumboro disease include trembling, ruffled feathers, poor appetite, dehydration, diarrhoea, huddling and depression. The vaccine reduces signs of the disease and damage to the bursa of Fabricius, an organ only present in birds which is part of their immune system.

Gumbohatch contains a live strain of IBD virus (strain 1052) that has been weakened so that it does not cause the disease.

Gumbohatch is a vaccine. Vaccines work by preparing the immune system (the body’s natural defences) to defend itself against a specific disease. Gumbohatch contains small amounts of weakened IBD virus attached to antibodies. When a chick or chicken egg is given the vaccine, the immune system recognises the weakened virus in the vaccine as ‘foreign’ and makes its own antibodies against the virus. When the chicken comes into contact with a similar IBD virus, these antibodies, together with other components of the chicken’s immune system, will be able to fight the infection and help protect it against the disease.

Gumbohatch was investigated in 5 laboratory and 3 field studies.

The laboratory studies involved chicks with maternal antibodies against IBD virus. The studies showed Gumbohatch to reduce clinical signs and damage to the bursa of Fabricius caused by very virulent (powerful) IBD virus infection, following vaccination of eggs or chicks.

The start of protection depends on the initial maternal antibody level of the batch of chickens and even then will be different for individual chickens. Studies have shown the start of protection to be from between 24 days of age and 28 days of age.

Gumbohatch must not be used in flocks without maternal antibodies against IBD virus.

The most common side effect with Gumbohatch (which may affect more than 1 in 10 animals) is a fall in the number of lymphocytes (a type of white blood cell which is part of the chicken’s immune system) in the bursa of Fabricius, followed by an increase and recovery of the bursa of Fabricius. This loss of lymphocytes does not cause immunosuppression in the chickens.

For the full list of restrictions, see the package leaflet.

Hands and equipment should be washed and disinfected after use of the vaccine.

After handling vaccinated birds or their litter, hands should be washed and disinfected because the virus is excreted by vaccinated birds for up to 3 weeks.

In case of accidental self-injection, medical advice should be sought immediately and the package leaflet or label shown to the doctor.

The withdrawal period is the time required after administration of a medicine before an animal can be slaughtered and the meat used for human consumption. It is also the time required after administration of a medicine before eggs may be used for human consumption.

The withdrawal period for meat and eggs from chickens treated with Gumbohatch is ‘zero’ days, which means that there is no mandatory waiting time.

The European Medicines Agency decided that Gumbohatch’s benefits are greater than its risks and it can be authorised for use in the EU.

Gumbohatch received a marketing authorisation valid throughout the EU on 12 November 2019.