(MCV4) protects against 4 strains ("types") of bacterial meningitis caused by the bacteria N. meningitidis. Bacterial meningitis is an infection of the fluid around the brain and spinal cord. It is a serious illness that can cause high fever, headache, stiff neck and confusion. It can also cause more serious complications, such as brain damage, hearing loss or blindness. Children should get the MCV4 vaccine at 11 to 12 years of age. Children older than 12 years of age who have not received the vaccine should receive it before starting high school.