AUSTIN (KXAN) — Pfizer vaccines for kids under 5 could be available by the end of February. As we know, children under 5 are the only group that remains ineligible for vaccination.

Last year Pfizer announced the two-dose shot appeared to be less effective at preventing COVID-19 in children ages two to five. Now the drug company is seeking emergency authorization from the U.S. Food and Drug Administration as soon as Tuesday for its COVID-19 vaccine in children ages six months to five years, which may leave many wondering… why?

Dr. Manish Naik with Austin Regional Clinic said there are two things to consider when looking at the effectiveness of a vaccine: if a vaccine is effective in preventing mild infection or its effectiveness against severe disease with the virus.

“I think what we’ve seen in these vaccine studies is that the vaccines have proven over and over again to be highly effective at preventing severe infection, so ending up in the hospital or dying. But the vaccines, depending on how many doses were given and what kind of variant is circulating, may not be as effective at preventing a milder infection,” Naik said.

The FDA will be looking at that data. Dr. Naik said this is something we’ve seen before.

“That’s exactly what we saw with omicron is folks that were vaccinated, were very well protected against severe infection, but not as well against just getting re-infected with a milder infection,” he said.

Omicron has had a significant impact on pediatric cases. Dr. Naik points out only about 30% of the pediatric population is vaccinated.

“When the virus spreads, unvaccinated individuals are at the highest risk of ending up with more severe symptoms. So, I think it’s just a function of that’s the group that’s not vaccinated,” he explained.

It’ll be up to parents to make an individual choice for their children.

“Thus far, all of the data that has been released has shown these vaccines are very effective. And they’re safe and side effects are uncommon, so we’re hoping to see that same result in these trials for younger children.”