Contacts With Varicella or With Children and Protection Against Herpes Zoster in Adults: A Case-Control Study

CONTACTS WITH VARICELLA OR WITH CHILDREN AND PROTECTION AGAINST HERPES ZOSTER IN ADULTS: A CASE-CONTROL STUDY [Thomas SL et al. Lancet 2002;360:678] The authors investigate the thesis that exposure to varicella-zoster virus protects adults from shingles by boosting the immune response to that virus. The study involved 22 general practices with recently diagnosed cases of zoster and controls with no zoster by history matched by age, sex, and practice. The participants were asked about contacts with varicella or zoster and with social or occupational contact with children as a proxy for varicella contacts. The results were based on data from 244 patients and 485 controls. The results showed a striking relationship between the frequency of zoster and contact with children, varicella, sick children, or persons with zoster during the prior ten years. Compared with those with no contact, the risk was reduced by up to 90% in those with extensive contacts. These data are summarized in Table 3, which enumerates the different methods to assess contact with VZV and the odds-ratio for zoster.TABLE 3Comment: This is a fascinating study that supports the concept that contact with VZV may boost the immunity to this virus to protect adults against zoster. There are several implications: 1) massive vaccination programs to eliminate chicken pox may increase the frequency of zoster in adults; 2) persons with extensive exposure to this virus or children likely to have chicken pox are probably relatively well protected; and 3) this supports the probability of benefit from varicella vaccination for adults.