COVID-19 vaccine boosters: Here's what we know and don't know

The question of who should get COVID-19 vaccine boosters – and when – isn't new but in recent days we've learned more.

Here's a rundown:

Who's been approved for COVID-19 vaccine boosters?

The U.S. Food and Drug Administration said last week that immunocompromised Americans should have access to a booster shot of Pfizer or Moderna because they may not have fully benefited from their initial series. 

What does it mean to be immunocompromised? 

Here's the list from the Centers for Disease Control and Prevention. It includes people who have:

• Been receiving active cancer treatment for tumors or cancers of the blood.
• Received an organ transplant and are taking medicine to suppress the immune system.
• Received a stem cell transplant within the last 2 years or are taking medicine to suppress the immune system.
• Moderate or severe primary immunodeficiency (such as DiGeorge or Wiskott-Aldrich syndromes).
• Advanced or untreated HIV infection.
• Active treatment with high-dose corticosteroids or other drugs that may suppress their immune response.

People in these groups represent about 3% of the nation's population.

What about people with other conditions?

The FDA has not yet recommended booster or third shots for anyone else, UC Health spokeswoman Amanda Nageleisen said Tuesday. If you're not sure whether your conditions counts, contact your doctor.

That's what the immunocompromized should do, Ohio's health director, Dr. Bruce Vanderhoff, said last week after the federal action. 

Dr. Steven Stack, Kentucky's health commissioner, said the commonwealth would include people in long-term care facilities as candidates for booster shots if they had compromised immune systems. But he also wanted them to talk to their doctors.

The third shot does not require a prescription and can be obtained at any existing site that has the vaccine.

"We have not had a regulatory or policing function for vaccines," Vanderhoff said last week, although he strongly discouraged people not in one of the CDC-designated groups from getting a third shot. 

Should your third shot be the same brand as the original ones?

If possible, yes, say doctors at University of Chicago Medicine based on the CDC's recommendations. "If you absolutely cannot find a matching dose of vaccine, it would be OK to get the other one," the medical system says on its website.

Why do we need boosters now?

Federal health officials have been looking at whether extra shots for the vaccinated would be needed as early as this fall. They've reviewed case numbers in the U.S. as well as the situation in other countries such as Israel, where preliminary studies suggest the vaccine’s protection against serious illness dropped among those vaccinated in January.

More evidence that the boosters were needed after six months for the immuno-compromised led the officials to act.

Will everyone be told to get a booster? 

USA TODAY and other national media report President Joe Biden's administration will likely recommend, possibly this week, that Pfizer and Moderna recipients get booster shots eight months after their initial series. 

“There is a concern that the vaccine may start to wane in its effectiveness,” said Dr. Francis Collins, the director of the National Institutes of Health, on Sunday. “And delta is a nasty one for us to try to deal with.

"The combination of those two means we may need boosters, maybe beginning first with health care providers, as well as people in nursing homes, and then gradually moving forward” with others, such as older Americans who were among the first to get vaccinations."

What if I had the J&J vaccine?

Officials were continuing to collect information on the long-term effectiveness of the Johnson & Johnson/Janssen vaccine, which was only approved in the U.S. in late February, to determine when to recommend boosters, sources told the Associated Press this week.

Are boosters different from the initial vaccine? 

The answer, so far, is no.

Dr. Paul McKinney, a University of Louisville School of Public Health and Information Sciences professor and associate dean as well as a member of the CDC Advisory Committee of Immunization Practices, said Tuesday that boosters are "the same entirely as the original doses."

They're "the same in the amount of mRNA that's present, the same in the volume of the injection." 

"I think over time there will be modifications of the mRNA vaccines," he said, "but the plan now is to use the same one because it looks sufficient for the present time to provide protection as needed." 

Is the U.S. a 'reverse Robin Hood'?

Global health officials, including the World Health Organization, have called on wealthier and more-vaccinated countries to hold off on booster shots to ensure the supply of first doses for people in the developing world.

The White House has said that even though the U.S. has begun sharing more than 110 million vaccine doses with the world, the nation has enough domestic supply to deliver boosters to Americans should they be recommended by health officials.

But an international system to share coronavirus vaccines was supposed to guarantee that low and middle-income countries could get doses without being last in line and at the mercy of unreliable donations.

It hasn’t worked out that way. In late June alone, the initiative known as COVAX sent some 530,000 doses to Britain – more than double the amount sent that month to the entire continent of Africa.

News about the shortfall led the news outlet Axios to call the situation a "reverse Robin Hood."

The Associated Press and Enquirer reporter Anne Saker contributed.