Feb. 2, 2009 -- It's the kind of party any child would want to attend, equipped with the coolest toys, the latest movies and even a few lollipops.
But there's one thing, or rather one very itchy child, that makes these toddler gatherings different from others.
Carrie, a mother from Atlanta, Ga., who asked that her last name not be used for privacy reasons, is one of those parents.
"My 7-year-old daughter has been to six of these parties," said Carrie, who also runs an online forum that helps parents organize and find parties in their neighborhoods. "Unfortunately, we have not caught the pox yet, but I'm keeping my eye out for more parties."
Carrie described these parties as "no different than a typical playdate." She said some parents might have the kids share a snack or a cup that could encourage the spreading of the highly contagious virus that has symptoms including a red rash, blisters, fever and headache.
Because the chickenpox vaccine is often given to children twice -- the child gets his or her first vaccine around 15 months and then a booster shot between the ages 3 and 4 -- Carrie said she became skeptical of its effectiveness and began to worry that if the vaccine didn't work her daughter would get chickenpox as an adult, when the symptoms are much worse.
"When I found out that children require booster shots, what that said to me was that there is no prolonged effect and that the vaccine doesn't work in the long term," Carrie said. "If it did, there would be no need for multiple shots.
"In my mind, that puts children at greater risk because they get vaccinated when they're young and if, for some reason, they don't get the booster shot or the booster shot isn't effective, the virus will be significantly more dangerous as they get older," she said.
"I'd rather my daughter get it naturally when she's younger than when she's older," Carrie said. "There's less risk when she's younger and she'll recover faster and easier."
The chickenpox vaccine, varicella, was first approved for use in the United States in 1995 and is now required in every state before a child can enter day care or school. Exceptions, including proof that the child has contracted the virus on his or her own, as well as parents who refrain from getting their children vaccinated because of religious reasons, vary from state to state.
Carrie said that her beliefs regarding vaccines and their possible link to autism, as well the instances she has seen when children who, despite getting vaccinated, still end up with the virus, have all played roles in her decision to hold off on vaccinating her daughter.
But while Carrie argues that she is doing what is best for her daughter, medical professionals argue otherwise, telling ABCNews.com that they're growing increasingly concerned about these chickenpox parties, which one pediatrician likened to a "game of Russian roulette."
Chickenpox Parties Gamble With Child's Health, Docs Say
"I'm aghast at the thought of these parties," said Dr. Louis Cooper, a spokesman for the Infectious Disease Society of America and a professor emeritus of pediatrics at Columbia University College of Physicians and Surgeons in New York.
"I deeply regret that parents who are trying to do the right thing just don't get it," Cooper said. "The fact is that they're right, chickenpox for most children is a mild illness. But when you see children who have the misfortune of one of the complications that are possible, you never forget it."
Cooper said that he has seen children contract conditions as serious as encephalitis, a brain infection, and has even had young patients die from the virus after developing flesh-eating bacteria.
"The child does not need to be immune-deficient or malnourished to have these complications," said Cooper, who recommends that all parents vaccinate their children against the virus. "It can be an ordinary healthy child, it's Russian roulette."
Dr. Paul Offit, a pediatrician specializing in infectious disease at the department of pediatrics at the Children's Hospital of Philadelphia, said that many parents who are against vaccinating their children argue that getting the virus naturally is more beneficial to the child's overall health.
"The thinking many parents have is that the natural infection is more likely to induce higher levels of antibodies and longer-lasting immunity than vaccines," Offit said. "That's generally true but the problem is if you make that choice you are also taking the risk of a natural infection, which can mean hospitalization and sometimes death."
Parents who refuse to vaccinate their children can also be a public health risk, said Cooper, who said that other strains of the chickenpox epidemic can be passed around as children who are not protected against the virus mingle with one another.
"You don't know who goes to a chickenpox party and might have some sort of immunity or may have a complication from it or who might spread it to someone else who, because of the medication they're on or because they're pregnant, are very susceptible to the disease," Cooper said. "Not vaccinating kids just spreads all the risks that are the reason the vaccine was created in the first place."
Vaccines Could Eliminate Virus Completely, If Everyone Gets Them
Researchers now say the chickenpox vaccine has slashed the occurrence of the disease in children by 90 percent but still worry that parents like Carrie are preventing the virus from disappearing all together.
Offit believes that if the chickenpox vaccine becomes as widely used as the measles vaccine was back in 1963, chickenpox would go the way of the measles: away.
"When we introduced the measles vaccine, which is another virus that gets worse for patients as they get older, in 1963, we dramatically reduced the instance of measles," Offit said. "That is what will happen here with chickenpox."
But Carrie doesn't agree. She says that the fact that some children still get the virus despite being vaccinated is evidence that chickenpox will never disappear completely.
"Something like this will continually mutate and potentially be worse than before," Carrie said. "Kind of the way the overuse of antibiotics has happened."
As for what doctors say about how parents who don't vaccinate their children might be putting them at increased risk, Carrie is unconvinced.
"Everything you do every day puts my child at risk," she said. "Putting her in a car puts her at risk.
"We can all only make the decisions that are right for our families, and this is what happens to be right for my family at this moment in time."