Table 2.

Malaria vaccine development challenges.

Malaria vaccine development challenges
Challenge	Commentary
Immune response(s) associated with protection are not fully defined.	• Antibody to NANP repeats of the circumsporozoite protein appear to protect at high titers • Role of antibody to other proteins and cell mediated immunity is not well understood • Innate immune responses appear to impair the development of adaptive, long-term protection
Strain Variation – impact on vaccine efficacy is not well defined.	• Different Plasmodium species cause malaria • Strain variation occurs within species • There is antigenic variation of clones as they progress through their life cycle
Protein expression and manufacturing	• Surface proteins important for blood-stage and transmission blocking vaccines are difficult to express in the proper conformation
Lack of R&D funding and commercial uncertainty	• Insufficient investment because of an absence of lucrative high-income markets