WASHINGTON (AFP) - The Covid-19 pandemic took a deadly toll on adults in the United States for two years while largely sparing children from the dire statistics.
But the rapid spread of the Omicron variant led to record paediatric infections and hospitalisations in the country, and anti-vaccination misinformation that tells parents the shots are dangerous is adding to the risk.
The chances of young people dying from Covid-19 remain low. The shots greatly reduce the odds of severe illness, and vaccinated mothers may pass protection to their babies, but vaccine hesitancy pushed online leaves both parents and children vulnerable.
Dr Wassim Ballan of Phoenix Children's Hospital said combating misinformation - from worries that the shots were developed too quickly to false claims that the jabs can impact future fertility - has become part of his job.
"Unfortunately, a lot of times when we're having this time with a family to discuss these things are when the child is already in hospital," he said of the problem.
Parents need to understand that the vaccines are "the most important tool for protection", especially to avoid multi-system inflammatory syndrome in children, a rare and dangerous complication that can follow a mild Covid-19 infection.
Only 27 per cent of children aged five to 11 have received a first dose of a Covid-19 vaccine in the United States. Hospitalisations reached a pandemic high of 914 children a day this month, up dramatically from the previous peak of 342 in September 2021.
The first week of January 2022 saw Texas Children's Hospital in Houston report 12 babies in intensive care with Covid-19.
Babies are too young for the Covid-19 shot, but Dr Kathryn Gray, attending physician of maternal-foetal medicine at Brigham and Women's Hospital, said research increasingly shows that vaccination during pregnancy leads to antibodies safely being transferred to the baby, offering limited protection.
Expectant mothers have also shown hesitancy to get the shot after they were excluded from initial clinical trials.
Dr Gray is among those who are monitoring the situation. "To date, there have been no safety signals (in the data)," she said, adding that she has "a lot of confidence" in telling patients the shot is safe during pregnancy for mother and baby.
"If they truly want to protect their infants, getting vaccinated is the thing that will protect them the most at this time."
Health agencies across the globe say the same, but the initial lack of data continues to be exploited in vaccine-opposed messaging on social media.
Posts on Facebook and Twitter claimed that stillbirths rose following the push to vaccinate pregnant people, even though going unprotected against the disease is the greater risk.
Epidemiologists Carla DeSisto and Sascha Ellington from the US Centres for Disease Control and Prevention said data from 1.2 million US births showed "no evidence the rate of stillbirths is higher overall during the pandemic".
But their research did reveal the risks of contracting the virus while pregnant.
"Compared to pregnant people without Covid-19, pregnant people with Covid-19 are at increased risk of adverse pregnancy outcomes, including preterm birth and stillbirth," the researchers said by e-mail.
Breastfeeding has also been the target of misinformation, with posts claiming that babies suffered rashes or even death upon nursing from a vaccinated mother.
The Society for Maternal-Foetal Medicine recommends vaccination for those who are lactating and says there is no reason to stop breastfeeding upon receiving the vaccine.
Misinformation became increasingly common in private Facebook groups where parents connect to share and sell breast milk, group moderators told AFP. In one of the largest such groups, Ms Bethany Bristow said she was concerned by requests for "unvaccinated milk".
The New York mother, along with her fellow moderators, decided to ban such requests, and the rules for her group of more than 10,500 parents now state: "Advertising or requesting vaccine free milk puts you, your children and community at risk."
Studies are finding specific benefits of milk from a vaccinated mother, according to Dr Laura Ward, co-director of the Centre for Breastfeeding Medicine at Cincinnati Children's Hospital.
"Antibodies have been detected in the breast milk of vaccinated lactating women. This means that breastfed infants may have some protection against Covid-19 if their mothers receive the vaccine," she said.
Dr Gray agreed. "Breast milk is full of antibodies based on a person's prior exposures both to vaccines and infection. Those things don't pose a risk to infants; they're actually helpful at protecting them," she said. "Any concerns or unknown pieces about the vaccine are dwarfed by the risk of Covid-19."