Exposure: Birth in the United States before 1980 is considered evidence of immunity except for health-care personnel (HCP), pregnant women, and immunocompromised persons. For these three groups, certainty regarding immunity is desirable because of the possibility of nosocomial transmission to high-risk patients; transmission of the virus to the fetus, which might result in congenital varicella syndrome; and the possibility of severe disease.

Pregnant women appear to be at higher risk for severe varicella and complications. Therefore, those exposed without definitive immunity should be strongly considered for varicella zoster immune globulin (VZIG). Administration of VZIG to these women has not been found to prevent viremia, fetal infection, congenital varicella syndrome, or neonatal varicella. Thus, the primary indication for VZIG in pregnant women is to prevent complications of varicella in the mother rather than to protect the fetus. Neonates born to mothers who have signs and symptoms of varicella from 5 days before to 2 days after delivery should receive VZIG, regardless of whether the mother received VZIG. In this situation be sure to communicate this information to the physician who will be caring for the newborn.

For a woman with unknown immune status, serologic serum testing should be performed. If the serum results are negative or unavailable within 96 hours from exposure, varicella zoster immunoglobulin should be administered.

Limited data suggest that the incidence of varicella is comparable among persons who receive varicella zoster immune globulin within 4 days of exposure and those who receive it more than 4 days (up to 10 days) after exposure, and attenuation of disease might be achieved with administration of varicella zoster immune globulin up to 10 days after exposure.

One study indicated an increase in varicella incidence with increasing time between exposure and administration of the immune globulin, but disease was attenuated in all cases. VariZIG can be obtained by healthcare providers from the sole authorized U.S. distributor, FFF Enterprises

(Temecula, California), by calling 800-843-7477 at any time or by contacting the distributor online at www.fffenterprises.com. As with any product used under an IND protocol, patients must give informed consent before receiving the product.

Active infection: Varicella pneumonia occurs in 10% of pregnant patients with VZV. Risk factors include smoking, advanced gestation and greater than 100 pox skin lesions.

Women with varicella infection in pregnancy should be treated with oral antiviral agents (e.g., acyclovir 800 mg 5 times daily). In cases of progression to varicella pneumonitis, maternal admission to hospital should be seriously considered. Intravenous acyclovir can be considered for severe complications in pregnancy (oral forms have poor bioavailability). The dose is usually 10 to 15 mg/kg of BW or 500 mg/m2 IV every 8 hours for 5 to 10 days for varicella pneumonitis, and it should be started within 24 to 72 hours of the onset of rash.