Vaccines are very important tools to reduce antimicrobial use and thereby slow down the emergence and spread of antimicrobial resistance. Vaccinations can also reduce production losses associated with disease and are therefore leading to more sustainable animal production. Poor biosecurity, animal regrouping or introduction of new animals to the herd might cause the appearance of previously unseen infectious diseases on the farm, therefore antibiotics sometimes are used to fight secondary or primary infectious agents. In order to reduce necessity of antibiotic use a well-organised prophylactic calf vaccination programme is advised. An effective vaccination protocol can be developed to fit most operations and management approaches.

The risk of mortality and morbidity in calves is highest during the first few weeks of life. The main causes of mortality change during the pre-weaning period: septicaemia is most likely to occur in neonatal calves (up to 28 days of age); diarrhoea in calves less than 30 days old, and bovine respiratory disease in dairy calves more than 30 days old. During this critical period, many farmers could consider vaccination and other preventive interventions to minimise the risk of diseases.

The decision of ‘if’ and ‘when’ to vaccinate and against what pathogen should always be done after consultation with the herd veterinarian. The veterinarian can determine the need for vaccination and the ability for vaccines to reduce the current health challenges on a farm. This includes a good knowledge of the herd health history, diagnostic sampling of animals, the disease challenges in the area, evaluation of specific risk factors and other management routines that might impact animal health e.g. colostrum management.

It is very important that vaccines are kept at the indicated temperature and it is vital that the manufacturer’s guidelines for injection and timing of vaccination are closely followed. Many management factors can limit the effectiveness of vaccination including inadequate nutrition, adverse environmental conditions or presence of parasites. Therefore, it is important that the animal is not suffering any undue stress, or nutritional deficiencies or clinical disease.

Most vaccines that are used for calves are made to be injected into muscle or subcutaneously, therefore sterile syringes and needles must be used in order to reduce iatrogenic spread of diseases. Ensure that the vaccines are transported and stored properly (often refrigeration is required). Vaccine preparation needs to be done with clean hands, and strictly according to producer instructions. Read the instructions on the package to make sure the correct dosage is given. Ideally use 16-18 gauge x 1.5-3 cm long needles. If using an automatic vaccination gun make sure it is sterilised and clean. Check the gun is calibrated and working correctly. Subcutaneously (SQ) this injection goes between the skin and muscle, but not into the muscle. It is the preferred method for protecting meat quality. Always use this method if it is an option given on the label. Intramuscular (IM) injection goes directly into the muscle. To minimize damage to meat, use the muscles in front of the shoulder.

Be sure to record: Date of treatment; Name, lot number and serial number of the product used; Route of administration and give boosters when required. Check calf health status after vaccination and if any unusual side effects are observed please report to your veterinarian.