Keeping up to date on hepatitis viruses, vaccines

The two boys had just finished their checkups and little sister was going last, as usual. Not to be outdone by her two older brothers, the 6-year-old brushed off all offers of help and leapt up to the exam table with the grace of an Olympic gymnast.

Though big brothers went first, it was their younger sibling who was a step ahead on that particular day. As a toddler, the girl had been given two hepatitis A shots as part of the revised vaccination schedule introduced in 2007.

Her brothers, who were 8 and 9, had not yet received the hepatitis A injections. Their parents thought that it made sense for the boys to play immunization “catch-up” with their little sister, so that all three of their children would be protected against this contagious disease.

Hepatitis A is a virus known to infect the liver, and infection can result in a monthlong illness featuring fever, vomiting and diarrhea, dark urine, clay-colored stools and jaundice. Deaths are rare, according to data from the American Academy of Pediatrics, with a hepatitis A case fatality rate of .01 percent to 2 percent.

While vaccines have not yet been developed for the rest of the “alphabet” of infectious hepatitis, it is fortunate that safe and effective vaccinations are available against both the hepatitis A and hepatitis B viruses.

The first inactivated hepatitis A vaccine was licensed for use in 1995. Childhood vaccination was initially aimed at protecting kids who lived in areas of the country with the highest rates of hepatitis A disease.

The two-dose hepatitis A series was then “rolled out” to other high risk populations, and in a 2007 policy statement, the AAP began recommended routine hepatitis A vaccinations for all children aged 12 to 23 months living in all 50 states.

The AAP estimates that there were approximately 300,000 cases of hepatitis A infections per year in the United States prior to vaccine licensure. By 2003, hepatitis A disease rates were already 76 percent lower than rates seen during the pre-vaccine years.

Academy experts explain that the hepatitis A virus is passed person-to-person through the fecal-oral route, and only rarely transmitted through contaminated blood products.

Hepatitis A can also be acquired after eating uncooked foods, such as salads and sandwiches prepared by infected food handlers, consuming produce tainted during the growing or processing stages, or, infrequently in developed countries such as the U.S., drinking water or eating raw shellfish from a contaminated water source.

AAP infectious disease experts report that most hepatitis A-infected children under the age of 6 show no symptoms of the disease, while more than two-thirds of affected older kids and adults will develop jaundice. For this reason, the group notes that jaundice in an adult child care worker or parent is often the first clue that a hepatitis A outbreak is unfolding in a day care setting.

Hepatitis A vaccines (Havrix or Vaqta) can be administered to children as young as 1 year of age, with a larger adult dose given to patients 19 years of age and up. A series of three combination hepatitis A-hepatitis B shots (Twinrix) is also available for use in adults 18 years and older.

Hepatitis A vaccines are inactivated, not live, and cannot cause disease. Vaccine side effects in children can include one to two days of redness, swelling and pain at the injection site, decreased appetite or headache.

AAP researchers find that an impressive 97 percent of children and 95 percent of adults develop protective antibodies within one month of their first hepatitis A vaccination, and “virtually 100 percent” of patients are protected after the second dose of the vaccine.

International travelers should strongly consider vaccination against the hepatitis A virus. In the 2012 Yellow Book on travelers' health, Umid M. Sharapov of the Centers for Disease Control and Prevention states that hepatitis A is often seen in the developing world and is “one of the most common vaccine-preventable infections acquired during travel.”

In the U.S., 85 percent of travel-related cases of hepatitis A occur following travel to Mexico, Central America or South America. See cdc.gov/travel for other geographic areas with an intermediate or high prevalence of the hepatitis A virus.

The CDC does not currently recommend any booster doses after the full primary series of hepatitis A vaccines. Protective hepatitis A antibodies have been shown to persist for at least five to 12 years and mathematical models predict that protection will last for at least 20 years following completion of the hepatitis A vaccine series.

Ÿ Dr. Helen Minciotti is a mother of five and a pediatrician with a practice in Schaumburg. She formerly chaired the Department of Pediatrics at Northwest Community Hospital in Arlington Heights.