Study flow diagram.

<p>Part I: study initiation. intramuscular vaccination: Group A; 1-ml vaccine, Group B; 2 -ml vaccine and Group C; non vaccinated. Part II: 1 month (30 days) post-study initiation (PSI), a second vaccination dose was administered to half of each vaccinated group as follows: A1; 1-ml, B1; 2- ml. Part III: 9 months (267 days) PSI, Group A was injected with 1 ml vaccine, Group B with 2 ml vaccine, Group C was not vaccinated and another group (Group D) was vaccinated with 1- ml. Part IV: 10 months (295 days) PSI, another vaccination dose was administered to half of each vaccinated group as follows: A3; 1- ml, B3; 2- ml, D1; 1- ml.