(CN) — There is a clear sense of hope when, a year into the Covid-19 pandemic, the country’s top health officials announce that we are starting to turn a corner.
Vaccination is steadily on the rise, and in new guidance, the Centers for Disease Control and Prevention has signed off on hanging out indoors and mask-free post-vaccine. More than 35 million have been fully vaccinated, or 10.5% of Americans, inching closer to the immunization rates that can finally put Covid-19's toll in the past.
But nearly a quarter of Americans still don’t have a vaccine that’s certified as being safe for them.
Children under age 18 make up nearly a quarter of the population. By crude calculations, without vaccinating kids it would be impossible to vaccinate 80% of the population, as prescribed by Dr. Anthony Fauci, to hit herd immunity and end the pandemic.
As it stands, there are no vaccines approved for kids under age 16 in the U.S.; the Pfizer vaccine is the only one authorized for ages 16 and up, while the Moderna and Johnson & Johnson vaccines have only been fully tested in adults age 18 and older.
Clinical trials are now in the works. Pfizer and Moderna are running trials with participants down to age 12, with results expected this summer. Once the vaccines are proven safe in those groups, the companies will move to lower age groups.
Johnson & Johnson announced plans to test their vaccine in infants, after trials are done in 12- to 18-year-olds.
Teenagers will likely be able to get vaccinated this fall, according to Fauci, the country's top infectious disease official. For younger age groups, the wait will likely be longer.
The science underlying why vaccines are different for children, and the vaccine development process details, explains how we got here.
Kids React Differently
In adults, side effects from the Covid-19 vaccine are mild. Most common is pain around the injection site, a sign of the immune system at work. Some people have also experienced headaches, fatigue and nausea.
In children, experts are most focused on the fever and other systemic reactions, which are those affecting the whole body, not just one part of it.
Those reactions can show up differently in children, explains Dr. Archana Chatterjee, pediatric infectious disease specialist and the dean of the Chicago Medical School.
“A child who has fever is evaluated sometimes a little bit differently than an adult who has fever,” said Chatterjee, who is on the FDA expert panel charged with recommending vaccine authorization. She noted that information from a phone interview with Courthouse News does not reflect the opinion of the Vaccines and Related Biological Products Advisory Committee or the FDA.
Chatterjee explained that, especially in very young children, a fever could be a sign of a more serious infection, like meningitis or pneumonia.
“So those safety data for children are particularly important,” she said.
Malaise, poor appetite, and vomiting reported in some adults, especially after the second dose, could also be an indication of more serious health problems.
“Again, those symptoms in children mean something different,” Chatterjee said.
Not only might children react differently to Covid-19 vaccines; they seem to respond differently to the illness itself. Kids are less likely to get very sick from Covid-19, and may be less likely to spread the coronavirus.
So the vaccine focus began with adults since they, and especially older people, are hardest hit by the disease.
Chatterjee said that vaccine trials don’t necessarily always start with adults.