The present invention relates to processes for purifying high-quality recombinant Plasmodium falciparum circumsporozoite protein at high yields. This process provides rCSP at high yields without the need for denaturing and refolding the protein. The present invention overcomes obstacles previously encountered in the field, including dimerization, aggregation, and N-terminal degradation of rCSP. The process provided by the invention is scalable, and can be applied to large fermentation batches. The invention also relates to stable liquid formulations of recombinant P. falciparum circumsporozoite protein, and processes for stably maintaining rCSP in a stable liquid formulation.
