2-Doses of Varicella Vaccine Offers Best Chickenpox Protection

Merck’s Varivax is a single-antigen varicella vaccine

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A new study reports that the 2-dose schedule of varicella vaccine provided optimum long-term protection for the prevention of Varicella. 

Varicella is commonly known as ‘chickenpox.’   

When compared with the combined vaccines, the segmented varicella vaccine offered individual protection against all severities of disease leading to a potential reduction in transmission. 

This phase 3b follow-up of an observer-blinded, randomized, controlled trial, was published in The Lancet on February 11, 2019. 

This study assessed the 10-year vaccine efficacy of 2 doses of a combined measles-mumps-rubella-varicella vaccine (MMRV), 1 live attenuated varicella vaccine (V) dose given after 1 measles-mumps-rubella vaccine (MMR) dose (MMR + V), versus 2 MMR doses (control vaccine). 

The per-protocol cohort included 2,279 children from the MMRV group, 2266 from the MMR + V group, and 744 from the MMR group. From baseline to a median follow-up of 9·8 years, 76 (3%) children in the MMRV group, 469 (21%) in the MMR + V group, and 352 (47%) in the MMR group had varicella. 

Vaccine efficacy against all varicella was 95.4 percent (95% CI 94·0–96·4) for MMRV and 67.2 percent (62·3–71·5) for MMR + V; vaccine efficacy against moderate or severe varicella was 99.1 percent (97·9–99·6) for MMRV and 89.5 percent (86·1–92·1) for MMR + V. 

During phase b, serious adverse events were reported by 290 (15%) of 1961 children in the MMRV group, 317 (16%) of 1978 in the MMR + V group, and 93 (15%) of 641 in the MMR group. 

This study’s data is good news since there is no cure for varicella/chickenpox. 

The Centers for Disease Control and Prevention (CDC) recommends 2 doses of chickenpox vaccine for children, adolescents, and adults. 

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The chickenpox vaccine was added to the childhood immunization schedule in 1995. 

The booster dose was added in 2006. It is rare for vaccinated people to spread the varicella vaccine virus, especially if they do not have a rash. 

Since the varicella vaccine program started, only 8 vaccinated people have been documented as spreading vaccine virus to others. 

The chickenpox vaccine is a live, attenuated vaccine and is not recommended for people with weakened immune systems. 

There is 1 chickenpox-only vaccine licensed in the United States: Varivax 

The CDC Vaccine Price List provides private sector vaccine prices for general information. 

And, vaccine discounts can be found here.           

Vaccines, like any medicine, can have side effects. Vaccine patients are encouraged to report negative side effects of vaccines to the CDC. 

This study was funded by GlaxoSmithKline Biologicals, which produces several vaccines.