Routine vaccination during childhood is among the most significant of all medical advances. Although many vaccine preventable diseases such as Haemophilus influenza b infection are now rarely encountered, others such as pertussis persist despite widespread vaccination. Concerns about vaccine efficacy, safety, and duration of protection continue to interfere with universal acceptance of some vaccines such as mumps-measles-rubella (MMR) vaccine despite demonstrated effectiveness. Important concerns about vaccination include the child’s age and underlying medical conditions, disease burden, vaccine efficacy and adverse reactions, and official recommendations.
General Rules for Vaccination
To achieve optimal protection, the clinician should vaccinate all patients in accordance with the timeline of the Centers for Disease Control and Prevention (CDC) universal vaccine schedule (Figure 7-1). With few exceptions all vaccine doses count for all time. Prolonged delay between vaccine doses does not necessitate restarting a vaccine series. Doses should not be given early, with the exception that a 4-day grace period be allowed. Storage and management issues are covered in CDC publications.
Recommended immunization schedule for persons aged 0–18 years, 2013, United States.
In the United States the estimated number of persons chronically infected with hepatitis B virus (HBV) is 1.25 million, 36% of whom acquired HBV during childhood. HBV infection becomes chronic in 90% of infected infants, with 30–60% of those infected before the age of 4 years, and 5–10% of those infected as adults. Each year in the United States, HBV kills about 6000 people. Up to 25% of infants infected with HBV will eventually die of HBV-related cirrhosis or liver cancer. Under universal hepatitis B vaccination, reported new cases of HBV fell to 3374 in 2010.
Hepatitis B virus transmission occurs primarily by blood exposure or by sexual contact with infected persons. The source of infection is not identified in 30–40% of cases. Some cases may result from in apparent contamination of skin lesions or mucosal surfaces; hepatitis B surface antigen (HBsAg) has been found in impetigo, in saliva, on toothbrush holders of persons chronically infected with HBV, and on used blood sugar testing stylets. Infants and children can transmit HBV.
Rationale for Routine Hepatitis B Vaccination
Although anti-HBV antibody levels diminish over time, most persons maintain protection through immunologic memory in lymphocytes. Immunologic memory and the long incubation period of HBV infection allow most immunized persons to mount a protective anamnestic immune response. Therefore low or absent serum antibody levels do not accurately predict susceptibility to HBV.
The number of vaccine doses administered, intervals between doses, genetics, prematurity, and underlying medical conditions affect immunogenicity. After the third dose of hepatitis B (HepB) vaccine, more than 95% of children seroconvert. Efficacy for HepB vaccine ...