Representing the Manufacturers of Animal Medicines
National Office of Animal Health Ltd
3 Crossfield Chambers, Gladbeck Way, Enfield, Middlesex EN27HF
Tel: (+44) 020 83673131 Facsimile: (+44) 020 8363 1155
e-mail: a.glennon@noah.co.uk
PressRelease
1November 2002
New leaflet from NOAH shows how vaccineshelp farm animal welfare and the production of healthy food from healthyanimals
Vaccination protects hundreds ofmillions of animals worldwide from disease and possibly death. And the latest briefingdocument from the National Office for Animal Health outlines how vaccines workto keep farm animals healthy and prevent disease. It also gives some casehistories showing how the health and welfare of different animals sheep,pigs, cattle, poultry and fish has been improved by the development ofvaccines. This in turn has helped food production, because healthy food comesfrom healthy animals.
Animals, just like humans, sufferfrom a range of infectious diseases. Asveterinary medicine has advanced, prevention of disease has become a priorityas healthy food comes from healthy animals.One of the best means of preventing disease, in the same way as inhumans, is by creating immunity in the animal.This is usually achieved by vaccination.
The principle of vaccination hasbeen established for over 200 years.Since those early days, enormous strides have been made in thedevelopment of vaccines, which have helped to prevent and in some caseseliminate many diseases in humans, farm animals and the family pet.
Animals which develop disease oftenrequire treatment with medicines so vaccination helps reduce the amount ofpharmaceuticals used in the treatment of animals. Vaccination presents no hazard to consumers of produce fromvaccinated animals.
Not all animals need everyvaccine. Some, like clostridial diseaseprevention in sheep, are basically routine, just like childhood vaccinationprogrammes. The vaccination programme chosen for farm animals depends on themanagement system, the location of the farm and the history of the herd orflock (and whether or not a disease is likely to be encountered). Most farm animals are young, and theseanimals (just like children) are often more susceptible to infection. So, forexample, calves often need to be protected against respiratory disease.
Whether fordisease prevention or treatment, the veterinarian, the animal owner and thepublic all have a right to expect that the research, development and bringingto market of animal medicines is reliably based on the triple standards ofquality, safety and efficacy. Theextremely stringent requirements for product registration set down in Europeanlaw reflect this. If these requirementsare not met, a vaccine will not be allowed on the market. Careful monitoringand review of products and disease patterns ensure that once on the market,vaccines remain safe and effective.There are very strict quality control processes to guarantee the safetyand efficacy of each dose of vaccine.
Todays vaccinesare very effective and have a remarkably high safety record. Millions of doses are used annually in theUK alone. The use of vaccines hasbrought significant levels of control against diseases that farm animalspreviously suffered.
There is a constant quest for newpreventive measures to meet the changing challenges to animal health. Indeed the diseases threatening animalsevolve themselves; just like with human influenza, when the medical professionneeds to be prepared with a vaccine to counter the particular strain that isprevalent at the time.
So the work goeson, as animal medicine companies continue to look for new vaccines to helpfarmers protect their animals.Vaccines, when available, provide a safe and effective answer to manyanimal welfare problems and represent an important field of ongoing research.
The briefing document is availablein full from the NOAH website www.noah.co.uk.Copies, with selected highlights of the case histories, are available free ofcharge from the NOAH office.
Ends
Notes for Editors
1. For further information contact Philip Sketchley or Alison Glennon on020 8367 3131, e-mail noah@noah.co.ukor visit the NOAH website www.noah.co.uk.
2. The National Office of AnimalHealth was formed on 1 January 1986 to represent the UK companies whichresearch, develop, manufacture and market licensed animal health products. Theassociation has 36 corporate members and 12 associate members. In 2001 NOAH'smembers accounted for around 95% of the 359 million UK animal health market,with additional valuable exports.
3. Vaccination of farmanimals, NOAH briefing document 22, is the latest in a series of informationleaflets explaining various animal medicine related topics.
4. Case histories are attached.
Sheep acase study
Clostridial disease in sheep and lambs
Clostridia are soil dwellingbacteria that can enter sheep even as they graze. They pose a constant andserious threat to flock health: before the introduction of vaccines they werecausing losses of up to 50% of lambs. The potential for this remains. Onset issudden, death is rapid and there is often no opportunity for successfultreatment - flock vaccination provides the only method of control.
Clostridial vaccine manufacturersreport that farmers who make mistakes in their vaccination regime - or areprevented by organic production contracts from using the vaccines routinely -can find that sudden and large-scale losses with clostridial diseases such aspulpy kidney or braxy occur.
Luckily clostridial vaccines makethis scenario much less common
Pigs acase study
Aujeszkys disease (pseudorabies)
Aserious, frequently fatal, viral infection in pigs, Aujeszky's was a diseasethat European vets and farmers were determined to eradicate. Pigs that dorecover can still carry infection, acting as a risk to others. Because they have had the disease, they bearresidual antibodies. Early vaccines contributed to a reduction in disease.However they left vaccinated pigs with antibodies indistinguishable from thosein an animal which had recovered from the disease but remained a carrier. So itwas impossible to distinguish a vaccinated animal from an infected one.
Oneoption to eradicate the disease involved removing all pigs with antibodies -this was actually used in Great Britain. But the vaccine was redesigned toremove from the vaccine virus the 'gene message' for a non-essentialglycoprotein, which is found in all known infective strains of the virus. Inparallel, a serological test was developed to accompany this. Now vaccinatedanimals could be differentiated from those naturally infected. This meant thatthere was no longer a need to slaughter all pigs with antibodies, andvaccination could play a role in the eradication schemes.
Poultry acase study
Newcastle Disease
Newcastle disease is caused by ahighly contagious virus that not only affects poultry (chickens in particular)but also can exist in carrier state in wild birds. Although endemic in many countries of the world, the UK has beenfree of the disease for some years.There is no treatment, but the UK's disease free status is maintained byroutine vaccination, usually via the drinking water or by coarse spray,although sometimes intranasal or intraocular vaccines are given.
Cattle case studies
Leptospirosis
Leptospirosis occurs in 60% of UKdairy herds, is an important bacterial disease of cattle and can lead tosignificant economic losses through symptoms as varied as abortion,reproductive failure and loss of milk production. Leptospirosis can also betransmitted from cows to humans where it can cause a flu-like syndrome.Vaccination against leptospirosis will protect cattle from developing thedisease and thus economic benefits for the farmer. Vaccination also has human healthbenefits as it will prevent transmission to farm workers.
Bovine Respiratory Disease
Calf pneumonia remains one of themost important causes of economic loss to cattle farmers as well as being acause of suffering to the affected animals. The total cost to farmers in the UKhas been estimated to be over 80 million.
Calves suffering from pneumonia canstop eating, lose weight, suffer pain, and in some cases may die. They also require extra nursing andtreatment with antibiotics and some cases anti-inflammatory medicines. Evenafter they recover affected calves are often slow to put on weight and growproperly.
There are a number of triggers ofcalf pneumonia including management and other facts but the actual causes are avariety of bacteria, viruses and mycoplasmas.Vaccines are now available which will provide effective control of themost common bacterial and viral causes of calf pneumonia. These vaccines aregiven before high-risk times such as housing and the winter months. This means that there is an improvement inanimal welfare as pneumonia is an important cause of suffering in animals, aswell as obvious economic benefits for the farmer since the total cost ofpneumonia can reach in the order of 80 per affected calf.
Fish casestudies
Trout Vaccination
EntericRed Mouth caused by Yersinia ruckeri first entered British trout farming in1982/3. From the first point of entry it spread rapidly around the country andbecame an endemic problem causing up to 20 percent mortality even with regulartreatments. Immersion vaccination was introduced in 1983 and the severity ofthe disease was contained but problems persisted particularly as the intensityof production increased. In recent years an oral booster vaccine has beenintroduced which has enabled trout farmers to produce their fish withoutsignificant antibiotic intervention.
Salmon Vaccination
Furunculosishas been present in wild salmon since the 1800's. With the advent of salmonfarming the disease became a serious problem causing significant losses. In thelate 1980's the viability of the industry was threatened by this endemicdisease problem. The industry invested very heavily with government backing anddeveloped a unique vaccine based upon special antigens linked to the infectionmechanisms of the bacteria causing the disease. This vaccine was introduced inthe early 1990's and in conjunction with good husbandry measures resulted in adramatic turn around. Mortalities to the disease are now almost unknown andwelfare of the farmed salmon is greatly enhanced.