Widespread resistance of malarial parasite to drugs like chloroquine has promoted attempts to develop a malarial vaccine to combat malaria. Why is it difficult to develop an effective malaria vaccine?
100%(a) Man does not develop immunity to malaria during natural infection ( 1 voter )
0%(b) Man is only an intermediate host and not the definitive host ( 0 voters )
0%(c) Malaria is caused by several species of Plasmodium ( 0 voters )
0%(d) Vaccines can be developed only against bacteria ( 0 voters )
Based On 1 Vote