Immunocompromised people may need a fourth dose of the vaccine, according to newly issued guidance from the U.S. Centers for Disease Control and Prevention.

Those patients may end up needing an additional shot six months after their third dose of the Moderna or Pfizer vaccines, the CDC said. The fourth dose can be of any of the three available vaccines, according to the agency.

This is in line with what the CDC has said before regarding immunocompromised adults. A third shot is considered necessary to establish vaccination for those patients and a boost would need to come six months later, according to the agency.

-ABC News' Anne Flaherty

An advisory panel at the Food and Drug Administration voted Tuesday in support of the Pfizer vaccine for kids 5 ages 11.

Seventeen people voted "yes" and one person abstained.

Next, the FDA will make a decision. Then, the matter heads to the CDC's independent advisory panel to deliberate and vote next week, and after that, the CDC director is expected to make the final signoff.

The earliest shots could be in arms is the first week of November.

-ABC News' Sasha Pezenik, Sony Salzman, Cheyenne Haslett

The Biden administration will begin shipping vaccine doses for kids ages 5 to 11 as soon as the Food and Drug Administration gives the green light in coming days, White House officials told governors on a private phone call Tuesday.

Doing so will allow children to begin receiving shots as soon as the Centers for Disease Control and Prevention signs off, which is expected around Nov. 4.

Jeff Zients, the White House coordinator on the federal response to COVID-19, said one big concern is the shorter shelf life for pediatric doses. In trying to make the vaccine easier for pediatricians to handle, the doses for kids 5 to 11 can be kept for only 10 weeks, compared with six to nine months for adult doses. 

"We don’t want to have wastage, so we encourage you to build flexibility into your distribution systems you can move around within your state or territory," he told the governors. Audio of the call was obtained by ABC News. "Just order what you need. We have plenty of supply. We can always get you doses on short notice."

-ABC News' Anne Flaherty

Officials with the Food and Drug Administration and Centers for Disease Control and Prevention opened Tuesday's FDA panel meeting by explaining how children 5 to 11 years old are impacted by the pandemic. They have accounted for over 1.9 million infections and over 8,300 hospitalizations, about a third of which have required ICU stays, officials said.

Nearly 100 children in that age group have died from COVID-19, making the virus one of the top 10 causes of death in this age range at this time, officials said.

The independent FDA advisory panel on Tuesday is debating whether to authorize the Pfizer vaccine for children ages 5 to 11. The panel's nonbinding vote is expected Tuesday evening.

After the panel votes on whether or not to recommend Pfizer, the FDA will make a decision. Then, the matter heads to the CDC's independent advisory panel to deliberate and vote, which is scheduled for Nov. 2 and Nov. 3. Once the CDC panel votes, the CDC director is expected to make the final signoff.

-ABC News' Sasha Pezenik

Moderna announced Sunday that the U.S. Food and Drug Administration is requiring additional time to review its adolescent COVID-19 vaccine for 12- to 17-year-olds.

The FDA expects to have the review done by January 2022.

Moderna is authorized in the U.S. for people 18 and older. The company has asked for authorization for 12- to 17-year-olds at the same dose as adults, which is 100 micrograms.

The Pfizer vaccine is currently available to anyone 12 years and old and could be available soon for 5- to 11-year-olds after it gets official Centers for Disease Control and Prevention recommendations.

-ABC News Eric Strauss