I depends. You can easily work into any Government hospital or primary health centres to get your yellow fever vaccination. But some of these institutions don't issue yellow fever vaccination card. You can get your yellow vaccination cards at the ministry of health near you, airports, boarders and also other authorized. If this will be used for travel purpose. It is advisable you get it 2 weeks before departure. The last time I checked, the requirement is Photocopy of your passport bio data page, Two passport photographs and a N1,000 fee .