Persons at risk for complications from a haemophilus influenzae type B vaccine include anyone who has had a life-threatening allergic reaction to the Hib vaccine and children younger than 6 weeks old. People who are moderately sick are also at risk of complications, states the National Vaccine Information Center.
Patients should be healthy before receiving the vaccine, notes the National Vaccine Information Center. Minor complications include fever and swelling at the injection site.
The Hib vaccine is very safe and protects children from Hib diseases, which can cause lifelong disabilities, advises the Centers for Disease Control and Prevention. The most common Hib disease is meningitis, which is an infection covering the brain and spinal cord.