Parents are lying to vaccinate their kids against COVID-19. Pediatricians say that's a bad idea.

• Parents of children younger than 12 lied about their kids' ages to get them vaccinated.
• Doctors are urging parents to follow the CDC's recommendations.

While the world waited for a pediatric vaccine against COVID-19 to be approved, some parents decided they couldn't wait any longer.

One mom, who asked to remain anonymous to protect her child's identity, recalls how in early August, she took her 11-year-old daughter to get the COVID-19 vaccine - months before it was approved for her daughter's age group.

"At the pharmacy, I filled out a simple form," she said. "I lied about not having insurance and about her birth year but gave her real name. The pharmacy tech verbally confirmed the information and quickly presented me with a COVID-19 vaccine card with my daughter's name and date of birth on it."

"A few minutes later, we emerged into the sunshine of the parking lot. My daughter, aged 11 years and 7 months, had a sore arm and a big smile on her face. 'I feel free,' she said. I did, too."

This mom knew that she was going against the recommendations of the FDA and CDC by vaccinating her daughter, but she believed it was worth the risk.

She's not the only one. In September, The Atlantic spoke to several parents who were lying to get their under 12 children vaccinated. Meghan, who asked for her last name not to be used for fear of consequences, lied about her 10-year-old son's age to get him vaccinated before in-person school started again. Maria, who also asked for her last name not to be used, vaccinated her child three months ahead of his 12th birthday. "He feels really happy and relieved. He feels safer," she told The Atlantic.

Now that five to 11 year-olds are eligible for the Pfizer vaccine in the US, the conversation is shifting to four-year-olds that look older.

Doctors are asking parents to follow CDC guidelines

Experts urge parents to follow the age recommendations when it comes to vaccines.

"The science is age-related. I cannot condone lying about a child's age to get them a vaccine. We just can't support that," Dr. Tom Lacy, a pediatrician from Florida, told Insider.

Lacy said that the age groups for vaccines aren't arbitrary. They're based on decades worth of research on how bodies respond to vaccination. The vaccine that's approved for five to 11 year-olds, for example, is a third of the dose of the one that's recommended for adults and children 12 and up.

"Children have a much more reactive immune system," said Lacy. "They form immunity at a lower dose than an adult does."

Another thing for parents to keep in mind: a child's weight will not impact their vaccine dose. It's all about the activity of their immune systems - and that's tied to a patient's age, not weight.

Dr. Angela Myers, Director of the Division of Infectious Diseases at Children's Mercy Kansas City, also urges parents to follow the FDA and CDC's recommendations and not try to vaccinate their children early.

"It is hard for parents of younger children to wait until there is a vaccine available for this age group. However, at this point, we don't have a recommendation to vaccinate children four years and younger and there could be differences to the vaccine in this age group," said Myers.