The trials, however, involved only adult subjects. Rutherford said that while the jury is still out on the studies in children, the outcome could be different for this group of vaccine recipients.
"The big loose end is children," he said. "They will likely still have to receive two doses, just like with the current seasonal vaccine."
But Treanor said that here may still be a chance that many pediatric patients, too, may be able to get by with one dose. He noted that the results from the trials are similar to what might be seen with a seasonal flu vaccine, at least in adults.
"If you could extrapolate, you would guess that it will turn out that kids [ages] 9 to 18 will also only need a single dose, but that really remains to be determined," he said.
Likewise, Dr. Christopher Ohl, associate professor of medicine at the Wake Forest University School of Medicine in Winston-Salem, N.C., said that it remains to be seen whether adults with weaker immune systems will need two doses of the vaccine.
"[It] will be important to see how one dose does in young children and immunocompromised adults, two groups were vaccination is especially important," he said.