OD ratio < 0.90 indicates no detectable Varicella Zoster IgG antibody. No evidence of infection or immunity.
OD ratio 0.91 - 1.09 is equivocal for Varicella Zoster IgG antibody. Suggest a new specimen to be collected and re-tested.
OD ratio > 1.10 is positive for Varicella Zoster IgG antibody. In asymptomatic patients, including prenatal screens, a positive value is consistent with previous infection or immunity.