Complex sentence: It is thought that this process is accountable for much of the clinical syndrome associated with malarial infection; therefore a vaccine given during this stage would be therapeutic and hence administered during clinical episodes to prevent further deterioration.
Split into simpler sentences: It is thought that this process is accountable for much of the clinical syndrome associated with malarial infection. Therefore a vaccine given to during this stage would be therapeutic and hence administered during clinical episodes to prevent further deterioration.