By Virginia Langmaid, CNN

New survey results published Tuesday by the Kaiser Family Foundation indicate that 43% of parents of children under 5 in the U.S. say they will not get their child vaccinated against COVID-19, the highest percentage in the year that KFF's Vaccine Monitor survey has been asking the question.

The U.S. Food and Drug Administration authorized COVID-19 vaccinations in children as young as 6 months in mid-June.

According to the KFF data, only 17% of parents of children between 6 months and 5 years old say their child has been vaccinated or will be as soon as possible. Another 27% say they will wait and see how well the shots work in other kids, and 13% said they will vaccinate their child only if required to do so for school or child care.

Although the percentage of parents unwilling to vaccinate children in this age group is high, it is not much lower in other age groups. According to the survey, 37% of parents of a child 5 to 11 and 28% of parents of a child 12 to 17 say they will not get them vaccinated against COVID-19.

Parents' responses varied significantly when broken down by partisanship and vaccination status. Just 21% of Democrat-leaning parents said they would not vaccinate their young child, compared with 64% of Republican-leaning parents. The survey found 27% of vaccinated parents said they would not vaccinate their child, compared with 64% of unvaccinated parents.

Concerns over side effects
"Concerns over the safety of the vaccines and potential side effects are widespread among parents of unvaccinated children ages 6 months through 4 years old," the report's authors wrote.

More than 8 in 10 parents of unvaccinated young children said they were concerned about serious side effects and about unknown long-term effects. Majorities of vaccinated parents of unvaccinated children also had these concerns.

While concerns about long-term effects and side effects were common across demographic lines, white parents reported fewer logistical concerns around vaccinating their young children. More than 4 in 10 Black parents expressed concern over taking time off work for vaccination, and 45% of Hispanic parents said they were concerned about getting their child vaccinated from a trusted provider.

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Interest in vaccine education
The survey data also shows room for improvement on vaccine education and a possible opportunity to get unvaccinated children vaccinated. More than half of parents of young children said they felt that government information around vaccinating their child was confusing. Nearly 40% of parents of unvaccinated children said they did not have enough information on where to find a vaccine.

"Across income groups, a majority of parents with household incomes of at least $90,000 say they think the information from federal health agencies about vaccinating children under 5 is clear, while majorities of those with lower incomes say it is confusing," the authors said.

One-time vaccination clinics were popular for adult vaccinations, but many parents of unvaccinated children are considering vaccination alongside regular medical appointments.

"Most parents of children under five newly eligible for the vaccine say they have not spoken to their pediatricians or other health care provider about the vaccine for their child," the authors wrote, and most of those parents say they will have that discussion at their child's next visit.

The U.S. Department of Health and Human Services recommends that infants and young children see a physician at 6 months, 9 months, 12 months, 15 months, 18 months, 24 months, 30 months, 3 years and 4 years old.