It’s spring, the season for sweet strawberries, colorful tulips, crisp vegetables — and a COVID-19 booster shot.

What? A spring dose of the COVID-19 vaccine?


Health experts with the U.S. Centers for Disease Control and Prevention (CDC) recently recommended an extra dose of the 2023-2024 COVID-19 vaccine for all people in the U.S. ages 65 and older.

Why? Simple. Hospitalizations and COVID-19 death rates for people who are 65 and older have been significantly higher than COVID deaths and hospitalizations among younger people over the last several months, and vaccine effectiveness is waning over time.

Health experts want to give extra protection to older people, so a committee of medical advisers to the CDC in February recommended a spring COVID-19 booster shot for everyone who is 65 and older.

To help you sort out the details about the new spring COVID-19 booster shot, we consulted with Dr. Michelle Barron, UCHealth’s senior medical director of infection prevention and control.

Who should get a spring COVID-19 booster shot?


CDC experts recommended the booster for everyone ages 65 and older. In addition, people who are immunocompromised also have been eligible for extra doses of the COVID-19 vaccine, said Barron, who is also a professor at the University of Colorado School of Medicine on the Anschutz Medical Campus.

Why are health experts recommending a spring COVID-19 shot for older people?

At this stage of the COVID-19 pandemic, older adults are having a tougher time when they get a bad case of COVID-19. That’s not surprising because immune systems in older people aren’t as strong as they are in the young, aside from younger people who are immunocompromised.

Here are some reasons why medical advisors to the CDC recommended a spring COVID-19 booster shot.

  • More than half of people who had to be hospitalized for COVID-19 between October and December of 2023 were older than age 65, according to CDC researchers.
  • Even four years into the pandemic, people continue to die of COVID-19, and people ages 65 and older have a much higher risk of dying of COVID-19 than younger people.
  • As people get older, the risk of dying from COVID-19 continues to rise. People ages 75 and older were much more likely to die if they contracted COVID-19 than people who were sick with COVID-19 and were 65 to 74 years old.
  • Fewer people of all ages have been getting the newest COVID-19 vaccines. Among people of all ages, only about 22% of U.S. adults have gotten the 2023-2024 COVID-19 vaccine, which was reformulated last year to better protect against the newest variants. Older adults have been more likely to get the newest vaccine, with about 43% of people ages 75 and older having received the newest shot, according to CDC data.
  • Vaccine effectiveness wanes over time, so especially for vulnerable people, it’s great to give the immune system a boost in combating COVID-19 infections.

So, if I got my last COVID-19 vaccine in the fall, when should I get my spring booster dose?

“You’ll want to wait at least four months since the last time you had a COVID-19 vaccine,” Barron said.

What if I have recently been sick with COVID-19? Should I still get a spring COVID-19 booster dose?

No, if you’ve recently gotten sick with COVID-19, you should wait about three months.

“You don’t want to get your new shot until it’s been 90 days since your last COVID-19 episode,” Barron said.

What if I want to get the newest COVID-19 vaccine that is expected to come out in the fall? Should I wait for that one? What’s the best timing to get a vaccine?

No, don’t wait for the fall vaccine. Unless you’ve recently been sick with COVID-19, you should not wait to get a spring booster dose. If you are 65 or older, or you are immunocompromised, you should go ahead and get a booster of the 2023-2024 COVID-19 vaccine now. (Learn all about the 2023-2024 vaccine that came out last fall.)

Vaccine makers and experts at the CDC are planning for newly formulated COVID-19 vaccines for the fall of 2024, but you shouldn’t wait to get that version. Anyone who gets a booster this spring will also be eligible to get a dose of the newest COVID-19 vaccine this fall.

Is it wise for everyone ages 65 and older to get a COVID-19 vaccine?

Yes, it’s very wise to get another dose, Barron said.

She and other researchers have done a study that is due to be published soon that shows why booster doses are so valuable for at-risk older adults.

“Hospitalizations are high in this group,” Barron said.

How effective are the newest COVID-19 vaccines?

Just like typical flu shots, the 2023-2024 COVID-19 vaccines are not perfect, but they do help prevent deaths and reduce hospitalizations, Barron said.

“Vaccine efficacy is about 50-to-60%,” Barron said.

Some people might argue that that level of vaccine effectiveness isn’t great, Barron said.

But Barron, who works hard every day to keep people healthy and out of UCHealth’s 14 Colorado hospitals, said vaccines that can keep as many as two-thirds of people from getting severely ill are incredibly valuable.

“That’s pretty compelling,” Barron said.

“These vaccines may not keep you from getting sick, but if they prevent you from dying and being hospitalized, simple logic tells you that’s a really good thing,” she said.

So Barron’s bottom-line advice to her older patients and relatives is quite simple: go get your spring booster dose of the COVID-19 vaccine. And, no matter your age, if you never got a 2023-2024 COVID-19 vaccine, you can still go get vaccinated.

I hear that the effects of COVID-19 vaccines wane over time. Is that true?

Yes. It’s true that vaccine effectiveness wanes over time. That’s why it’s wise for people who are ages 65 and older to get a booster shot this spring.

And even though vaccine effectiveness wanes over time, Barron said it’s still tremendously helpful to get COVID-19 vaccines and booster shots because they significantly reduce deaths and hospitalizations.

Barron is a co-author on an important new CDC study that evaluates how COVID-19 vaccines work over time.

According to the study, vaccine effectiveness for the 2023-2024 COVID-19 vaccine (which people started receiving last fall and will get this spring) was strongest in the first seven to 59 days after people received a dose of what was called the “monovalent” shot. Vaccine effectiveness decreased to about 43% in the two to four months following vaccination, the researchers found. While not perfect, the vaccines nonetheless continue to provide some protection over time.

What are hospitalizations like right now for COVID-19, flu and other respiratory illnesses like RSV?

“We continue to see as many cases of COVID-19 as we do for flu,” Barron said. (It’s also possible for patients to get both flu and COVID-19 or RSV at the same time. Read more about that.)

“COVID-19 is still a significant component of the respiratory illness pathogens that are requiring hospitalization now,” Barron said.

Of course, there’s pandemic fatigue. Do people forget that vulnerable patients are still dying of both COVID-19 and flu?

Yes, absolutely. Barron said many people don’t think much about flu or COVID-19, but these respiratory illnesses can cause death and can make people very sick.

“People can die and do die from the flu. That’s also true, of course, for COVID-19,” Barron said.

“Thankfully, we know that the vast majority of people who get COVID-19 now are just going to feel sick and stay home and recover. Or you may just have a minor infection, and that’s great,” Barron said. “But for some people — especially those who are older or immunocompromised — you can have some really terrible impacts from these viruses.”

What do you think about the newest CDC guidelines that no longer require people to isolate themselves if they tested positive for COVID-19 but no longer feel sick?

Barron thinks the newest CDC guidelines simplify things.

“The message I have for all of this is to use good old-fashioned common sense. If you are sick, please don’t visit your grandmother and grandfather who are older and vulnerable. Also, please don’t spend time with your friend who is just finishing cancer treatments or visit a brand new baby,” Barron said. “All of those people are at risk for having complications if they get sick, regardless of the virus that we’re talking about.

“So, be smart,” Barron said. “We all understand the concept of protecting people from viral infections.

What do you recommend as the right approach if people are sick, even if they haven’t gotten tested and don’t know if they have COVID-19, the flu, RSV or a cold?

“If you feel sick, and you’re coughing, sneezing or can’t eat or drink, you should stay home. Your coworkers will be appreciative if you’re not hacking all day long again,” Barron said.

“Whatever the cause, if you have a fever, you should not be at work or at school until you’ve no longer had a fever for at least 24 hours without taking anti-fever medications like Tylenol or ibuprofen,” she said. “That’s actually a rule at most schools, and it’s not new. It’s just good old-fashioned common sense. If you’re sick, you should be home, and you don’t want to spread whatever you have to someone else.”

What are the basics of the newest CDC guidelines for isolation after a positive test for COVID-19?

Medical experts advise people to stay home and avoid contact with other people until at least 24 hours after they have symptoms like a fever, bad cough or other signs of illness.

Once a person’s fever breaks, they should still be cautious about exposing others since some people can remain contagious later. CDC experts encourage people to use good hygiene practices like frequent hand washing and wear a mask if they’re in crowded indoor settings. It’s also wise to keep your distance from vulnerable people and take steps to be in well-ventilated areas.

Under the old guidelines, CDC experts encouraged people to isolate for at least five days. Now that more people have built up some immunity to the virus that causes COVID-19 through vaccines and prior infections, fewer people are getting severely ill from coronavirus infections. Guidance for people in health care settings may be different. Read some Frequently Asked Questions about the new guidelines for COVID-19.

In what ways do the guidelines simplify how we should behave if we’re sick?

Barron thinks the new guidance is simpler because it’s the standard advice that we should all be using if we’re sick, regardless of whether we have COVID-19, the flu, RSV, norovirus or another infectious illness.

If you’re sick, stay home. If you have symptoms of an illness, don’t expose others, especially vulnerable people.

Editor’s Note: The Colorado Times Recorder occasionally posts articles, like this one, about COVID-19 from UCHealth Today, which is published by UCHealth, the hospital associated with the University of Colorado School of Medicine. Our goal is to provide as many people as possible with accurate information about medical issues that are poisoned by misinformation, particularly as discussed on social media and talk radio.