Before their immune systems mature, young children are especially vulnerable to infections — and to falling far more ill than adults might with certain common illnesses.
That’s why childhood vaccination programs have been such a boon for public health. In the past 30 years, recommended childhood vaccines have prevented more than 1.1 million deaths and 32 million hospitalizations in the United States.
The recommended schedule for these vaccines is set by the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices. The panel, which reviews the recommendations and decides whether to adopt them, is meeting this Thursday and Friday.
Health Secretary Robert F. Kennedy Jr. fired all 17 members of the panel in June and has since handpicked their replacements, a number of whom have at some point expressed skepticism about vaccines.
Mr. Kennedy has questioned the need for many childhood vaccines, a refrain that has been echoed by President Trump.
“It’s too much liquid, too many different things are going into that baby at too big a number,” Mr. Trump said in September during a briefing at the White House.
The specifics of the upcoming meeting are unknown, but members are expected to discuss the timing of vaccines and the safety of ingredients. The members will also consider whether to delay the hepatitis B vaccine to a later age.
Children vaccinated in line with current recommendations receive protection against a number of diseases, including infections that can lead to paralysis, brain damage and difficulty breathing. Those who aren’t given recommended shots or who follow an alternative schedule may be at higher risk of developing these preventable illnesses.
“When we start spacing things out, the danger is that either the child gets exposed, or we never get them caught up and they miss out entirely,” said Dr. Beth Thielen, a pediatric infectious disease physician at the University of Minnesota.
What changes have already been made to the childhood vaccine schedule?
In May, the C.D.C. dropped its recommendation that healthy children receive the Covid-19 vaccine. (It previously had recommended a Covid shot for children 6 months and older.)
In September, the panel convened and discussed limiting the use of the hepatitis B vaccine; currently, all infants get the first dose of the shot at birth, a practice that has slashed the number of childhood hepatitis cases by around 80 percent since the recommendation was implemented in 1991. Decades of research have established the safety of the hepatitis B vaccine. The committee members decided to table the discussion, which will be picked up again this week.
The C.D.C. also recommended that children under 4 receive the varicella (chickenpox) vaccine separately from the shot for measles, mumps and rubella, rather than as a combined immunization. The move is unlikely to directly affect most children; a majority of toddlers already received the vaccines separately for their first of two doses, Dr. Thielen said.
Experts are concerned that changes to the vaccine schedule have the potential to further undermine confidence in vaccines.
“That’s my biggest concern — that it raises doubts in people’s minds about the existing schedule,” Dr. Thielen said.
Why is the vaccine schedule set the way it is?
To understand why doctors recommend vaccinating on a specific schedule, it’s helpful to understand what protection babies need and when.
“We want them to have maximal protection when they need it, and when they need it is when they’re at the highest risk of serious infection and before they are exposed,” said Dr. Leila Posch, a pediatric infectious diseases physician at Children’s Hospital Los Angeles. “Second, we want to give vaccine doses when their immune system is mature enough to respond to them well.”
The hepatitis B vaccine is recommended at birth because the infection, which can lead to permanent liver damage and cancer, is highly transmissible during delivery. It can also spread through drops of blood on surfaces or skin. Before the vaccine, about 18,000 children were infected each year, about half of them at birth. Today, hepatitis B is vanishingly rare among U.S. children.
At a baby’s eight-week checkup, doctors recommend shots that protect against whooping cough, tetanus and polio, along with other infections that can cause pneumonia, brain swelling and heart damage. At this point, a baby’s immune system will have matured enough to effectively make antibodies, proteins that protect the body from specific infections, in response to these shots.
These vaccines require additional doses over the next year and a half to maximize protection, explained Dr. Ben Hoffman, a former president of the American Academy of Pediatrics and a pediatrician at Oregon Health and Science University.
Despite the C.D.C.’s decision to stop recommending Covid vaccines for babies, professional organizations, such as the American Academy of Pediatrics, and some states still recommend beginning them at about 6 months of age. While the rates of severe Covid infections are lower in children than they are in adults, Dr. Thielen said that she had cared for many babies and children hospitalized with complications, including inflammation of the heart and blood vessels.
“The potential harm of natural Covid infection to nonimmune children is very real,” she said. “We have a tool to prevent complications that has been remarkably safe.”
Thanks to protective antibodies that they receive from their mothers in utero, babies are born with immunity to a few dangerous infections, including hepatitis A, measles, mumps and rubella. That means certain vaccinations can wait until that immunity wanes — around age 1, Dr. Thielen said. Babies also receive vaccines against chickenpox at this age.
Right before kindergarten, children receive booster shots for a number of vaccines to give the immune system another update.
What happens when parents stray from the recommended schedule?
Parents who choose not to follow the recommended schedule often do so because they have concerns that babies receive too many vaccines at once, Dr. Thielen said, or they may worry that certain vaccines are given too early. There is no evidence that the number of vaccines children receive is harmful, she said. And all of the vaccines in the schedule have been rigorously tested for safety — both individually and to make sure they’re safe and effective in combination with one another, Dr. Posch said.
On the other hand, there are only limited studies on alternative schedules. Those that exist include much smaller numbers of patients.
What pediatricians do know is that these alternative schedules, which may forgo certain vaccines or stagger the recommended shots, leave children vulnerable for longer periods.
“I have seen families who have unfortunately missed opportunities to get vaccines, and those vaccines then can’t do the job of protecting their kid,” Dr. Hoffman said.
Doctors are also seeing more children become sick with infections that they once saw only rarely. A few years ago, a child arrived at Oregon Health and Science University with a tetanus infection, Dr. Hoffman said. “Before that, I don’t think a single person at O.H.S.U. had ever seen tetanus,” he said. The child was in the intensive care unit for months.
Dr. Thielen said she had cared for children with measles and permanent brain injuries from meningitis. All of them, she said, had fallen ill with diseases that vaccines could have prevented.
Where can parents turn for evidence-based recommendations?
With the C.D.C.’s vaccine recommendations possibly in flux, some experts recommend turning to other sources for evidence-based recommendations on the childhood vaccine schedule. Organizations including the American Academy of Pediatrics, American Academy of Family Physicians, and the American College of Obstetricians and Gynecologists publish their own schedules.
The Vaccine Integrity Project, which systematically combines these organizations’ recommendations, is another useful resource, Dr. Thielen said.
The post What to Know About the Vaccine Schedule as it Comes Under Review appeared first on New York Times.
