Adjuvants are the 'extras' added to anything, not necessarily just vaccines, which help it in its action or make it more convenient in usage. That could be thi

Adjuvants are the 'extras' added to anything, not necessarily just vaccines, which help it in its action or make it more convenient in usage. That could be thickeners or perhaps suspending agents to prevent the active ingredients settling too quickly on the bottom; that could be preservatives to stop it growing bugs; that could be ascorbic acid to prevent the active substance being oxidised and made inactive; that could be anti-freeze agents to prevent it freezing to become a solid. A lot of the 'extras' listed in the ingredients of prepackaged food could be considered to be adjuvants.