"Needles and syringe should be boiled in water for 5 minutes and cooled before reuse. It is important to treat the clean syringe and needle carefully. Do not touch the end of the needle after cleaning. Put the needle gently on the syringe holding the needle with the sharp end upwards. Put the vaccine vial upside-down and press the needle gently through the plastic seal of the vial cap. Pull the syringe handle gently down, while sucking the vaccine out of the vial until the syringe is full. Press the syringe handle back until you reach the right volume. Make sure that there are no air bubbles trapped in the syringe or the needle. Air bubbles will give the wrong dose to the chickens. Normally a full 1 ml syringe will match 10 doses, one for each of ten adult birds. This however depends on the weight of the bird and the type of vaccine, and the application method. When the birds grow older, injections are given in the breast or thigh muscles. Depending on the vaccine type, eye drops may also be used for adult birds" (Network for Small Poultry Development, "Keeping Village Poultry").
"Vaccines should be given either early morning, before letting the birds out of the chicken house or when the local birds are easy to catch resting in the trees. When vaccinating adult poultry for the first time, you should preferably be two persons, one holding the bird, the other one vaccinating" (Network for Small Poultry Development, "Keeping Village Poultry").
Information Source: Network for Small Poultry Development, "Keeping Village Poultry", A Technical Manual on Small Scale Poultry Production, www.smallstock.info