In a previous post (HAV vaccination: how long will it take?), it was noted that U.S. HAV immunization rates are poor but much better in states that have employed a strategy of implementing universal vaccination for a longer period.  Another article provides reassurance that once patients are vaccinated that the immunity is quite durable (Hepatology 2012; 56: 516-22).

197 infants and children were followed after HAV immunization; these patients were divided into three groups; two dose immunization at 6 & 12 months (group 1), at 12 & 18 months (group 2), and at 15 & 21 months(group 3).  Anti-HAV serology was followed sequentially. At 10 years, almost all children retained seroprotection (>10 mIU/mL) levels, >95% of group 2 & 3.  In group 1,  7% of infants born to anti-HAV negative mothers and 11% of infants born to anti-HAV positive mothers did not have protective antibody levels.

Conclusion: Seropositivity for HAV persists for at least 10 years after vaccination with two-dose regimen when administered to children 12 months of age and older.

Something to think about (unrelated to blog post):

A Zen master was once asked, “What is the key to happiness?”

He answered, “Good judgment.”

“How do I gain good judgment?” he was questioned.

“Experience,” was the reply.

“How then do I get experience?” the student further probed.

“Bad judgment,” were his final words.

(quoted previously in Pediatrics and from the following link QUOTATIONS AND PASSAGES ON EXPERIENCE)