Do you need a COVID-19 booster? Yes, you do

There is a lot of information in the news right now about COVID-19 booster shots. We want to clear up misconceptions and confusion around these shots and discuss why public health officials are recommending them now. We’ll also talk about who should get a booster dose of the COVID-19 vaccine for better protection against infection.

Understanding COVID booster shots

A “booster shot” is not something unique to COVID-19. In fact, booster shots are common for many of the vaccines that doctors and health officials recommend for everyone. The most common booster shots people get are annual flu vaccines and boosters for Tdap (tetanus, diphtheria and pertussis) every 10 years.

Similar to the rationale behind giving boosters for those illnesses, COVID booster shots can help your body maintain a higher level of immunity and protection against breakthrough COVID infections. A breakthrough infection occurs when someone who is fully vaccinated gets COVID-19. That person can still get sick—though most vaccinated people will have milder symptoms—and they can spread COVID-19 to others.

In addition, there is evidence that you are at an increased risk for contracting COVID-19 six months after you've completed your initial vaccinations (or two months after the Johnson & Johnson vaccine). A booster shot will give you continued immunity.

Who is eligible for COVID booster shots?

Booster vaccines are available right now for everyone over the age of 18. Eligible individuals may “mix and match” the vaccines, meaning they may choose any of the three COVID-19 vaccines authorized in the U.S. to receive as a booster dose.

Booster shots are recommended for people aged 18 and older who received a Johnson & Johnson vaccine at least two months ago or who received the Pfizer-BioNTech or Moderna vaccines at least six months ago.

Additional doses of the vaccine are also recommended for people who are moderately to severely immunocompromised because these individuals are especially vulnerable to COVID-19. Technically, this dose is considered part of the primary vaccine series, and is not a booster dose since this shot helps people with these conditions to build the same level of immunity as a two-dose vaccine series.

The rationale for COVID-19 booster doses

We are still fighting COVID-19 and  there is evidence that protection from the vaccine wanes over time. Boosters enhance immunity and stop community spread of the virus. A clinical trial showed that patients who received a booster were 95.6% protected against the disease -- including the Delta variant.

  • The most extensive study on COVID booster shots came from Israel, where the government administered a booster shot to almost all adults. Researchers evaluated 1.1 million people over the age of 60 who got a booster. After 12 days, those people were almost 20 times less likely to test positive for COVID-19 and have severe symptoms than people who did not get a booster shot.
  • Currently available data suggests that immunity against COVID-19 goes down over time and a booster shot can help your body stay protected longer.

COVID-19 vaccine booster shots Q&A

Both the flu vaccine and COVID booster vaccines are approved by the FDA. There is no evidence that it is risky to get both shots together, so if you need a flu shot and a COVID booster you can get both at the same time.

The CDC guidance says that everyone ages 50 year and older, and everyone ages 18 years and older and live in a long-term care setting, should get one. This is stronger than just a recommendation. It is especially true because the Delta variant is more contagious than previous strains of the virus.

There is some evidence that the immune protection that develops after getting a COVID infection may not last as long as immunity after full vaccination. Getting a booster shot, even if you are still experiencing “long-hauler” symptoms, can be helpful. You may want to consult with your doctor.

Monoclonal antibody treatments are effective for people within the first 10 days of being infected with COVID-19. If you were treated with this therapy, you should wait at least 90 days before getting a COVID booster shot. Otherwise, the treatment might interfere with the vaccine and keep it from doing its job to build up immunity in your body to future COVID infections.

The good news is that it’s very easy to get a booster shot. You can make an appointment at your local county health department or find a pharmacy nearby that has doses available by visiting Many pharmacies also take walk-ins. Don’t forget to take your vaccine card with you.

You can also check for any upcoming on-campus vaccination clinics.

You can find more information about COVID booster shots and older adults from our physicians at University of Utah Health by watching a video of our Facebook Live broadcast.

Information was accurate at the time of its posting. Due to the changing nature of the COVID-19 pandemic, scientific understanding and guidelines may have changed since the original publication date.