Why vaccinate a baby for HepB?

Childhood infection with Hepatitis B (“Hep B”) is rare in the USA and yet within moments of birth, American babies are routinely vaccinated for the disease.  Hepatitis B is primarily transmitted through unsafe sex or by sharing needles during intravenous drug use, but can also be transmitted from a pregnant mother to the fetus. The HepB vaccine was added in 1991 to protect the infant from the possibility of developing Hepatitis B disease in the case of HepB-positive mother.
However, in 2007 there was only a 1 in 480 risk of a live birth to a HepB-positive mother according to reported cases (the CDC estimated that due to potential unreported cases, the risk could be as high as 1 in 216). [1] [2]  Because of the low risk of the pregnant mother being HepB-positive, many developed countries (such as the UK, Denmark, Netherlands, Switzerland, Sweden, Norway, Finland, Ireland, Iceland, and Japan [3] [4]) routinely test pregnant women for HepB and administer the vaccine to the newborn only if the mother is HepB-positive (see Vaccine schedules in different countries).
The long term effectiveness of the vaccine is unknown.  Immunity from the vaccine is thought to be often lost prior to the teen years during which there is potential for unsafe sex and sharing needles during intravenous drug use, the primary risk factors for disease transmission.  As example, as estimated 42.3% of infants vaccinated with HepB at birth will lose immunity according to one study [5]. Thus, there may be no benefit from this vaccine when administered to a child whose mother is not HepB-positive.
Research suggests that the Hepatitis B vaccine generates statistically significant risk of vaccine-injury. A 2008 scientific study indicated that boys who received Hep B vaccines had a 9x greater risk of needing special education services.[6]  In 2009, an abstract of a study in the journal Annals of Epidemiology indicated that boys who received Hep B vaccines had a 3x greater risk of developing autism (see article by journalist David Kirby on this study HERE). According to a CDC study, the Hep B vaccine is also associated with a 20% increased risk of asthma (HERE) as described by the researchers: “In our main analysis we found that Hib and hepatitis B vaccines were associated with 18 and 20% increases in asthma risk, respectively.” A 2011 study found that the HepB vaccine changes gene expression, including the expression of seven genes that are biomarkers for liver injury (HERE).  The HepB vaccine contains aluminum adjuvant, which has been shown to cause neurological damage in mice (see Does aluminum in vaccines cause injury?).

So why are USA mothers not screened first to see if their children actually need the vaccine?  The reason is a combination of: a) the desire to prevent development of chronic Hepatitis B disease when transmitted from the mother and b) to vaccinate individuals while they are children, since there are currently no mechanisms to require adults to vaccinate with HepB (whereas with children, vaccines are generally a requirement for schools unless the child has an exemption).  However since the advent of HepB vaccination in 1991, the prevalence of Hepatitis B in adults has not changed. [7] Given the vaccine-injury risks and the indication that there may no benefit to a child whose mother is not HepB-positive, it appears that other countries with HepB-screening programs have a more common-sense approach versus the universal HepB vaccination policy in the USA.

[1] http://pediatrics.aappublications.org/cgi/content/full/111/Supplement_1/1192

[2] http://www.cdc.gov/nchs/data/nvsr/nvsr57/nvsr57_12.pdf

[3] WHO (2009). Progress towards global immunization goals. Geneva: WHO. 

[4] Centre for Disease Control and Prevention. Global progress toward universal childhood hepatitis B vaccination, 2003. MMWR 2003;52:868-70.

[5] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2910296/

[6] Gallagher, C. and Goodman M., “Hepatitis B triple series vaccine and developmental disability in US children aged 1-9 years”, Toxicological Environmental Chemistry, Vol. 90, NO. 5 (Sept. –Oct., 2008): 997-1008.

[7] Wasley, A. et al., “The Prevalence of Hepatitis B Virus Infection in the United States in the Era of Vaccination,” The Journal of Infectious Diseases, 202 (July, 2010): 192-201.