Virus and antigen purification and conjugation

A method for enhancing a measure of stability of a conjugated compound comprising a protein and a virus particle, the method comprising:

• activating the virus particle and then mixing the virus particle and an antigen in a conjugation reaction to form a conjugate mixture,
• wherein when placed in an unrefrigerated environment at a storage temperature and after a time period of at least 42 days following a release date of the conjugate mixture, the conjugate mixture demonstrates a stability that exceeds an initial stability of the conjugate mixture stability for the antigen alone as measured by one or more of antigen concentration, antigen integrity, or antigen potency.