Varicella
Varicella (i.e. Chicken pox) is a highly contagious disease caused by Varicella Zoster virus. It is usually a self-limited disease that lasts 4- 5 days and is characterized by fever, malaise and a generalized vesicular rash typically consisting of 250-500 lesions. Varicella is transmitted from person to person by:
-
direct contact, droplet or aerosol from vesicular fluid of skin lesions
- Secretion from the respiratory tract.
The average incubation period for varicella is 14-16 days.
The period of contagiousness of infected persons is estimated to begin 1-2 days before the onset of rash and end when all lesions are crusted, which is usually 4-5 days after onset of rash.
Recommendations for the use of Varicella virus vaccine (VARIVAX)
Persons < 13 years of age
Persons of this age group should receive one 0.5 mL. Dose of vaccine sub-cutaneously
Children who have not been vaccinated previously and who lack a reliable history of Varicella infection are considered susceptible.
2 - 18 months of age
All children should be routinely vaccinated at 12-18 months of age. Varicella virus vaccine may be administered to all children at this age regardless of prior history of Varicella; however, vaccination is not necessary for children who have reliable histories of Varicella.
18 months-12 years of age
Varicella vaccine is recommended for immunization of all susceptible children by the 13 Th. birthday
Varicella should be administered to susceptible children during the routine immunization visit at 11-12 years of age but may be administered at any time during childhood
Persons > 13 years of age
Persons in this age should be administered two 0.5 mL doses of vaccine, subcutaneously, 4-8 weeks apart.
Vaccination is recommended for susceptible persons who have close contact with persons at high risk for serious complications (e.g. health care workers and family contacts of immuno-compromised persons)
Vaccination should be considered for susceptible persons in the following groups who are at high risk of exposure:
- Persons who live or work in environments in which transmission of Varicella Zoster virus(VZV) is likely (e.g. teachers of young children, day care employees, residents and staff in institutional settings)
- Persons who live or work in environments in which Varicella transmission can occur (e.g. college students, inmates, staff of correctional institutions and military personnel).
- Non pregnant women of child bearing age. Vaccination of women who are not pregnant but may become pregnant in the future, will reduce the risk for VZV transmission to the fetus. Varicella immunity may be ascertained at any routine health care visit or in any setting in which vaccination history may be reviewed (e.g. upon college entry).
- International travelers: Vaccination should be considered for international travelers who do not have evidence of immunity to VZV (e.g. serologic test).
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