CDC allows fourth COVID shots for people over 50. Should you get one?

Federal health officials said Tuesday that some people who want a fourth COVID-19 shot can now get one, setting up possible confusion and the potential for supply problems if the response is enthusiastic.

The Centers for Disease Control and Prevention announced that people who are 50 or older and received their third shot at least four months ago may get a fourth dose.

The new guidance also said people with compromised immune systems could get a fifth shot, and that people who received two doses of the Johnson & Johnson vaccine can consider getting a Pfizer or Moderna shot.

The Colorado Department of Public Health and Environment announced Tuesday that the state is ready to give additional booster doses, though it doesn’t have enough doses on hand to give one to everyone who may qualify.

The current guidance somewhat followed a previous pattern, with an additional dose recommended first for people with compromised immune systems, then for a broader group. People with compromised immune systems have been allowed to seek a fourth dose for several months.

The language was different, however, saying that older people may receive a fourth dose, while they should get a third one if they haven’t already.

Making the guidance less prescriptive could be a positive step, because it allows people to make their own decisions about risk, in consultation with their health care provider, said Dr. Ross Kedl, an immunologist and microbiologist at the University of Colorado School of Medicine. He recommends that people who are over 75 or who are over 65 and have chronic conditions get a fourth dose in the near future.

“If you have Type 2 diabetes… I would be on a booster pretty quickly,” he said.

The state health department estimated about 1 million Coloradans who are 50 or older have received three doses, making them eligible for a fourth now or in the coming months. Only about 470,000 adult-sized doses of the vaccine are available in Colorado, however, which could cause a problem if every eligible person wanted one.

It’s not clear how likely that is, since uptake of third shots was significantly lower than first and second doses. About 1.6 million people in Colorado are eligible for a third dose, but haven’t yet received one, said Heather Roth, the state health department’s immunization branch chief.

“We urge Congress to secure funding to purchase enough vaccine doses for all and invest in variant-specific vaccines or a pan-COVID vaccine protecting against a range of variants should the science and data demonstrate the need,” Diana Herrero, deputy director for the state health department’s division of disease control and public health response, said in a news release.

Data from Israel, which rolled out fourth shots before the United States did, suggests that older people and those with health conditions that could put them at higher risk benefited most from another booster, Kedl said. The reduction in risk was less impressive than when people who got two shots received their third, though, he said.

“The degree of change between third and fourth shots is significantly less than between second and third,” he said. “But its benefit is not zero.”

The Israeli data hasn’t shown any increased risk of severe reactions compared to the first three shots, Kedl said, and the odds of experiencing flu-like symptoms in the days after being vaccinated are similar for all doses.

Some people have decided they want to wait for an omicron-specific vaccine, which normally would seem like the best strategy, Kedl said. Early data from primate studies suggest it may not be more effective than the existing vaccines, however, and a new variant could be dominant by the time it comes to market, he said.