Varicella (Chickenpox) Vaccination: Information for Health Care Providers

Children 12 months through 12 years old

• 2 doses (0.5 ml each) of varicella vaccine should be given subcutaneously, separated by at least 3 months.
• MMRV vaccine is approved for healthy children in this age group.

Single-antigen vaccine and MMRV vaccine can be used for the routine 2-dose varicella vaccination.

• First dose: age 12 through 15 months
• Second dose: age 4 through 6 years

For the first dose, CDC recommends that MMR and varicella vaccines be given separately in children 12 through 47 months old unless the parent or caregiver expresses a preference for MMRV vaccine. For the second dose of measles, mumps, rubella, and varicella vaccines at any age (15 months–12 years) and for the first dose at age ≥48 months, use of MMRV vaccine generally is preferred over separate injections of MMR and varicella vaccines.

Both vaccines may be given at the same time as other vaccines for children age 12 through 15 months and age 4 through 6 years.

People 13 years or older

• 2 doses (0.5 ml each) of the single-antigen varicella vaccine subcutaneously 4 to 8 weeks apart
• MMRV vaccine is not approved for people in this age group.

For more information on the two vaccines for varicella, see MMR & Varicella Vaccines or MMRV Vaccine: Discussing Options with Parents.

For package inserts, see Varivax^® and ProQuad^®.

Vaccine effectiveness

One dose

• 1 dose of single-antigen varicella vaccine is:
  • 82% effective at preventing any form of varicella
  • Almost 100% effective against severe varicella

Two doses

• In a pre-licensure clinical trial, 2 doses of vaccine were:
  • 98% effective at preventing any form of varicella
  • 100% effective against severe varicella
• In post-licensure studies, two doses of vaccine were:
  • 92% (range 88% to 98%) effective at preventing all varicella

In Children with HIV-infection

• 1 dose of single-antigen varicella vaccine is:
  • 82% effective at preventing any form of varicella

It is not known how long a vaccinated person is protected against varicella. But, live vaccines in general provide long-lasting immunity.

• Several studies have shown that people vaccinated against varicella had antibodies for at least 10 to 20 years after vaccination. But, these studies were done before the vaccine was widely used and when infection with wild-type varicella was still very common.
• A case-control study conducted from 1997 to 2003 showed that 1 dose of varicella vaccine was 97% effective in the first year after vaccination and 86% effective in the second year. From the second to eighth year after vaccination, the vaccine effectiveness remained stable at 81 to 86%. Most vaccinated children who developed varicella during the 8 years after vaccination had mild disease.1
• A clinical trial showed that children with 2 doses of varicella vaccine were protected 10 years after being vaccinated. Fewer people had breakthrough varicella after 2 doses compared with 1 dose. The risk of breakthrough varicella did not increase over time.2
• A meta-analysis that included 1-dose vaccine effectiveness reported through 2015 found a pooled estimate of 82% within the first decade. Considering the age of participants in the studies and vaccine recommendations in each country, the median time since vaccination is likely lower than 10 years. Four studies reported decline in VE with time since vaccination; however, the differences did not reach statistical significance.3
• Two doses of varicella vaccine add improved protection, with a pooled estimate of 92% (assessed ~5 years after vaccination).

Varicella vaccine must be kept at freezing temperatures. Below is a link to a document that outlines storage best practices for frozen vaccines.

• Vaccine Storage Best Practices for Frozen Vaccines—Fahrenheit (F) [2 pages]

The Vaccine Storage and Handling Toolkit is a comprehensive resource for providers on vaccine storage and handling recommendations and best practice strategies. It includes considerations for equipment – both storage units and temperature monitoring devices – strategies for maintaining the cold chain, routine storage and handling practices, inventory management, and emergency procedures for protecting vaccine inventories.

• Two doses (0.5 ml each) of the single-antigen varicella vaccine (Varivax) should be given either subcutaneously or intramuscularly, separated by at least 3 months
• MMRV (ProQuad) vaccine is approved for healthy children in this age group. MMRV may be given subcutaneously or intramuscularly.

Single-antigen vaccine or MMRV vaccine can be used for the routine two-dose varicella vaccination.

• First dose: age 12 months through age 15 months
• Second dose: age 4 years through age 6 years

For the first dose, CDC recommends that MMR and varicella vaccines be given separately in children age 12 months through age 15 months unless the parent or caregiver expresses a preference for MMRV vaccine.

Both vaccines may be given at the same time as other vaccines for children age 12 months through 15 months and age 4 years through 6 years.

• Two doses (0.5 ml each) of the single-antigen varicella vaccine (Varivax) should be given either subcutaneously or intramuscularly, separated by 4 to 8 weeks
• MMRV (ProQuad) vaccine is NOT approved for people in this age group.

For package inserts, see Varivax^® and ProQuad^®.

People who got varicella vaccine but should not have

People who got varicella vaccine but should not have because of contraindications should be monitored for adverse reactions. Any adverse reactions should be reported online to the Vaccine Adverse Event Reporting System (VAERS). If you need further assistance with reporting to VAERS, please email info@VAERS.org or call 1-800-822-7967.

People who had varicella or a positive serologic test for varicella in the past are less likely to develop serious adverse reactions to the vaccine, unless they have had a prior serious allergic reaction to any ingredient of a vaccine. For more information about potential adverse reactions, see Vaccine Safety.

Pregnant women should not get vaccinated. For more information, see Guidelines for Vaccinating Pregnant Women: Varicella. To report administration of VZV-containing vaccines to a pregnant woman, call the manufacturer at 1-877-888-4231. See Merck's website for more information. Inadvertent vaccination of pregnant women should also be reported to VAERS.

The pregnancy outcomes of women inadvertently vaccinated with VZV-containing vaccines immediately before or during pregnancy were monitored by the Merck/CDC Pregnancy Registry for VZV-Containing Vaccines during 1995-2013. During this period, no cases of congenital varicella syndrome and no increased prevalence of other birth defects were detected. Although a small risk for congenital varicella syndrome could not be ruled out, the number of exposures registered each year (approximately two varicella-susceptible women exposed during the high-risk period for congenital varicella syndrome) was too low to improve on the estimate of the risk and the registry was discontinued.

People who got herpes zoster vaccine instead of varicella vaccine

A dose of recombinant herpes zoster vaccine (Shingrix) administered instead of varicella vaccine does not count as a dose of varicella vaccine.

People who got the recombinant herpes zoster vaccine should be monitored for any serious adverse reactions. Adverse reactions and vaccine administration errors should be reported online to the Vaccine Adverse Event Reporting System (VAERS). If you need further assistance with reporting to VAERS, please email info@VAERS.org or call 1-800-822-7967.