Neutralization of FMDV was also possible through the region of 201-213 amino acids of the same protein. It has thus been shown that small synthetic peptides representing these regions of proteins can show immunogenic response and can, therefore, be used for development of a vaccine.

An alternative approach to find out the immunogenic region of protein is through the study of gene coding the protein. Recently it has been shown that a cloned gene of an immunogenic protein of a pathogen (feline leukaemia virus) can be cut into fragments by DNAase and these fragments can be cloned in lambda phage, where they may express.

Actually a vaccine for malaria in the form of a synthetic peptide has already been prepared and is being tested for its suitability. This is the first example of a vaccine developed in the form of a synthetic peptide.
Recently, it has been shown that immunogenic region of protein of a pathogen can also be identified, by eluting it from purified MHC molecules (MHC = major histocompatibility complex). Different MHC allelic variants re available in cells for binding of different proteins and they can be, purified using specific T cells.

Peptides can be eluted from these purified I'IHC molecules and sequence of such peptides can be determined and used for manufacturing synthetic peptides to be used as vaccines.
Using the above three approaches, vaccines against several pathogens including the following pathogens have either been produced in recent years or are expected to be produced in the near future.