A universal infant vaccination campaign in China has led the Hepatitis B virus (HBV) to more than double its rate of "breakout" mutations. These mutations may enable the virus to elude the vaccine, necessitating new vaccination strategies. Researchers at the Chinese Centers for Disease Control and Prevention and University of North Carolina, Chapel Hill, report their findings in an article published ahead of print in the Journal of Virology.
Until a universal vaccination program for infants
was implemented in 1992, nearly ten percent of Chinese—children
included—were infected with HBV. The vaccination campaign
has protected an estimated 80 million children, dramatically reducing
the percentage of children under 5 who are infected, from nearly 10
percent in 1992 to less than one percent in 2005. But these gains are in
danger of being eroded as the virus develops surface mutations.