Live attenuated virus vaccines
Live attenuated virus vaccines mimic natural exposure while avoiding disease, in the expectation that immunologic memory and lifelong immunity will be induced. These vaccines generally require only one or two immunizations, since the immune responses they induce are very durable. Many licensed vaccines in use today are based on this concept.

Low Income Countries under Stress (LICUS)
Low-income countries under stress (LICUS) are characterized by very weak policies, institutions, and governance. Aid does not work well in these environments because governments lack the capacity or inclination to use finance effectively for poverty reduction.

Lyophilized vaccine
Formulations of vaccines that have been freeze-dried during manufacture before the vial is sealed. They need reconstituting with liquid before use.