LAS VEGAS (KLAS) – Around 3% of Americans are now eligible for a third dose of Pfizer and Modernas COVID-19 vaccines — and some have already gotten their shot.

If you are immunocompromised and it has been 28 days since your second shot, you can get a third. Everyone else must wait. And the timeline is still unclear for those who got the Johnson and Johnson vaccine. 8 News Now asked an expert why.

“We were glad that it was available, and we were definitely relieved to get it,” said Las Vegas resident Larry Hatab.

Hatab and his wife both received their third dose of the Moderna COVID-19 vaccine this week. They are immunocompromised, making them eligible for the shot. Hatab says the decision was easy to make.

“We just figured the more protection, the better, because we both have to be very careful,” Hatab said.

For everyone else, U.S. health officials recommend the extra dose be administered eight months after getting the second shot of the Pfizer or Moderna vaccine. Brian Labus, an infectious disease epidemiologist and assistant professor at the UNLV School of Public Health, says eight months is the ideal time. That is because it is late enough to get lasting immunity, following the initial six or so months of protection, but early enough to prevent COVID complications if someone were to contract the virus.

“We study the antibody levels in people. We look at see how those decline over time. We also look at increased risk of infection or serious disease,” Labus said. “By looking at that, we get an idea of how antibodies change over time in the human body, and from that, we figure out about eight months is the ideal time for that third dose after the second dose.”

8 News Now also asked Labus why no recommendations have been made so far in terms of getting an extra dose of the Johnson and Johnson vaccine.

“We started using the Johnson and Johnson vaccine later, so we don’t have as much data on the long-term effects of that vaccine on the body,” Labus said. “It’s something that takes a while to study. We’re just not at that point with the J&J vaccine.”

Some people are skeptical about getting an extra dose.

“I believe in good health, but I’m not interested in having to continue to take a booster shot,” said Las Vegas resident Kortney Olson.

But Hatab believes getting the extra vaccine dose, when you become eligible, is all for the greater good.
“It’s not just your own protection,” Hatab said. “It’s protecting other people.”

The third dose of the Pfizer and Moderna COVID-19 vaccines will be available to the general public starting the week of September 20, assuming the FDA and CDC sign off on it.