The vaccines effectiveness is extraordinary since it has the capability to cure or fix any infection or disease. But there are some limitations to the vaccine’s effectiveness! For example, the effectiveness of vaccinations is limited by your age, health or nutritional status. Even if the host does develop antibiotics, protection may not be adequate, Immunity might develop too slowly  to be effective in time. However even a partial, late, or weak immunity such as one resulting from cross immunity to a strain other than the target strain may mitigate an infection, resulting in a lower mortality rate. Lower morbidity, and faster recovery.