Progress on coronavirus vaccines has moved remarkably fast since the novel virus was first identified and sequenced in January. The leading experimental shots are now in the final stage of clinical trials, with results expected as soon as next month.

But that progress has focused on crafting and testing a vaccine for adults. Children have yet to be involved in any coronavirus vaccine trials, leaving some experts to worry that children could be left without a viable COVID-19 vaccine for some period of time.

Drugmakers usually test a vaccine in children before seeking approval to give the shots to kids.

Business Insider asked the leading drugmakers - Pfizer, Moderna, AstraZeneca, and Johnson & Johnson - for their plans on testing their coronavirus vaccines in children. All four companies told us that they plan to do so, but none provided an estimate on when a shot could be available for children.

Right now, all four companies are in the final stage of testing their experimental shots in adults.

Moderna told Business Insider it plans to start a pediatric trial for its shot before year's end, pending approval from regulators.

"Subject to regulatory approval, our intent is to start by the end of this year," said Ray Jordan, Moderna's chief corporate affairs officer.

Jordan added that Moderna doesn't have anything more to share publicly on the timing, protocols, or funding for pediatric studies "because these regulatory discussions are still underway."

Johnson & Johnson chief scientific officer Paul Stoffels said J&J is committed to eventually running pediatric trials. Opening studies for children "will come later in the year" after safety is established in adults, Stoffels said on a September 22 call with reporters.

The other drug companies didn't say when they'd start their studies in kids.

Drugmakers give general commitment with few specifics to studying vaccines in children

The lack of information on how and when drugmakers plan to test their coronavirus shots in kids has caused concern among some pediatricians and vaccine experts.

"Right now I'm pretty worried that we won't have a vaccine available for kids by the start of next school year," Dr. Evan Anderson, a paediatrician at Children's Healthcare of Atlanta, told The New York Times' Carl Zimmer.

BI asked leading drugmakers if they expect to receive government funding to run these trials. None directly answered the question, although an AstraZeneca spokesperson said its deal with the US government includes pediatric studies.

The US government's coronavirus vaccine initiative has committed roughly $US10 billion to drug companies to fund trials, produce doses and pre-purchase a supply of several experimental vaccines. Operation Warp Speed leaders have not laid out, or even mentioned, a plan for vaccinating children over the past few months.

A couple factors explain why children are being left behind in this research.

In general, researchers start testing an experimental shot on the least vulnerable population - young and healthy adults - and then start expanding into more vulnerable groups as clinical data accumulates that shows it's worth testing the shot. That can include testing in older people and people with other illnesses.

A recent change to Pfizer's coronavirus vaccine study shows how this works. The pharmaceutical giant recently boosted its enrolment target from 30,000 volunteers to 44,000 people, and it also said it now wants to enrol 16- and 17-year-olds, as well as people with hepatitis C, hepatitis B, and HIV.

"To address the burden of disease in pediatric populations younger than 16, we are working actively with regulators on a potential pediatric study plan," a Pfizer spokesperson said.

While children may not typically suffer the severe outcomes of COVID-19 seen in the elderly, finding a vaccine for kids is still an important element of countering this pandemic.

"Although children infected with SARS-CoV-2 are more likely to be asymptomatic, symptomatic and sometimes serious illness occurs," Pfizer's spokesperon said. "In addition, children may prove important in spreading SARS-CoV-2 to the community."

Specifically for COVID-19, fatality and hospitalisation rates are far worse for older people. Childhood illnesses from the novel coronavirus have been exceedingly rare, like a handful of reported cases of Kawasaki disease. Drug companies said their priority in responding to the pandemic was protecting populations most susceptible to severe outcomes first.

An AstraZeneca spokesperson said the company would start enrolling children "once sufficient data are gathered in adults, indicating that AZD1222 has the potential to be safe and protective in children."

This article was originally published by Business Insider.

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