Low induction of varicella-zoster virus-specific secretory IgA antibody after vaccination

Breakthrough after varicella vaccination occurs in approximately 2.6%simila r to 18.6% of immunocompetent children, but the reason has not been demonst rated clearly. As a first defense, specific secretory IgA antibody on the m ucosa plays an important role in preventing invasion of microorganisms. To examine induction of varicella-zoster virus (VZV) specific secretory IgA af ter natural infection and vaccination and its booster mechanisms, 143 saliv ary samples were tested by ELISA. The VZV-secretory IgA values were signifi cantly higher in the matched children after natural chickenpox than in thos e after vaccination, although the total secretory IgA did not differ betwee n them. Two (7%) of the vaccinees lacked the sIgA antibody. In the elderly and in immunocompromised children, the VZV-secretory IgA values were no low er than those in healthy children, and they did not lack VZV-secretory IgA. The doctors and nurses taking care of patients with chickenpox had higher values than the other groups as did individuals who had had herpes tester r ecently. VZV-secretory IgA was thought to be stimulated by exogenous and re activated endogenous VZV to neutralize VZV with weak activity. These result s suggest that low or no induction of VZV-secretory IgA antibody after vacc ination may be one of the possible explanations for a breakthrough. J. Med. Virol. 62:46-67, 2000. (C) 2000 Wiley-Liss, Inc.