Skip to content

Children's Vaccines Health Center

Second Dose of Vaccine Cuts Chickenpox Cases Even More, Study Finds

Kids and adults benefit from children receiving both recommended immunizations, researcher says
Font Size
A
A
A

WebMD News from HealthDay

By Serena Gordon

HealthDay Reporter

TUESDAY, Oct. 8 (HealthDay News) -- Two doses of chickenpox vaccine are better than one, new research confirms.

After the introduction of the second dose of chickenpox vaccine, the rates of chickenpox infection dropped 76 percent and 67 percent at two U.S. sites tracked for the study on opposite sides of the country.

Rates of infection in adults and infants -- two groups who generally don't receive the vaccine -- also went down, suggesting that higher levels of immunity in the population are decreasing the amount of circulating chickenpox.

"The first dose of vaccine was highly protective for reducing hospitalizations, deaths and other severe complications, but it wasn't fully protective against mild disease. There were still mild breakthrough cases, and these people could transmit the disease to those who hadn't been vaccinated," said Dr. Rachel Civen, senior study author and a medical epidemiologist with the Los Angeles County Department of Public Health.

"In 2006, it was recommended that a second dose be given between the ages of 4 and 6. And, we've seen a continuous significant decline since then, and the drops are across all age groups. The transmission is less throughout the whole community," she said.

Results of the study were published online Oct. 7 and in the November print issue of Pediatrics.

Chickenpox, which is also known as varicella, is a highly contagious viral disease. Before the varicella vaccine was introduced in the United States in 1995, about 4 million people had the chickenpox each year, according to the U.S. Centers for Disease Control and Prevention.

Although many people tended to think of chickenpox as a relatively mild infection, it caused more than 10,000 hospitalizations each year and about 100 deaths annually, according to background information in the study.

After the vaccine was introduced in 1995, the incidence of chickenpox went down by 90 percent and deaths from the disease dropped by 88 percent, but there were still outbreaks occurring. That's why experts decided to add the second dose in 2006.

The current study was designed to see how well the second dose of vaccine kept chickenpox under control. It included two sites -- one in Antelope Valley, Calif., and the other in West Philadelphia.

Today on WebMD

Baby getting vaccinated
Is there a link? Get the facts.
syringes and graph illustration
Get a customized vaccine schedule.
 
baby getting a vaccine
Know the benefits and the risk
nurse holding syringe in front of girl
Should your child have it?
 

What To Know About The HPV Vaccine
Article
24 Kid Illnesses Parents Should Know
Slideshow
 
Nausea and Vomiting Remedies Slideshow
Article
Managing Immunization Schedules For Kids
Video
 

Doctor administering vaccine to toddler
Video
gloved hand holding syringe
Article
 
infant receiving injection
Tool
pills
Quiz
 

WebMD Special Sections