1. It is an attenuated vaccine , unlike most influenza vaccines, which are inactivated vaccines. 2. It may become possible to target oral attenuated vaccines to the gut mucosa. 3. These are : inactivated vaccines, attenuated vaccines , virus-like particle vaccines and subunit vaccines. 4. Ruprecht's finding immediately undermined some support for a live attenuated vaccine . 5. Live attenuated vaccine candidates are the furthest along in development. 6. History is on the side of live, attenuated vaccines ; it is a classic approach. 7. The potential for contact immunity exists primarily in " live " or attenuated vaccines . 8. Live attenuated vaccines have a long and illustrious history. 9. Low-attenuated vaccine strains may cause damage to the bursa of Fabricius and immunosuppression in susceptible chicks. 10. Additionally, the administration of live, attenuated vaccines is contraindicated for individuals taking immunosuppressive doses of methylprednisolone.