You May Need a COVID-19 Booster Shot. But Not Yet

Older woman wearing a mask receiving a vaccine.

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Key Takeaways

  • Earlier this month, Pfizer and BioNTech announced that they are developing a COVID-19 booster shot.
  • Experts say there is no evidence just yet that booster shots are needed at this time.
  • But booster shots might be needed in the future, especially for vulnerable populations like older adults.

Earlier this month, Pfizer and BioNTech announced that they are developing a COVID-19 booster shot in case a third shot may be needed to boost immunity about six to 12 months after full vaccination.

Experts aren't sure just how long immunity will last. A recent Pfizer preprint study—which means that it hasn’t gone through peer review and should not be used to guide clinical practice—showed that the efficacy of the Pfizer-BioNTech vaccine declined six months after the second dose was administered.

For some of the first eligible groups to get vaccinated—older adults, healthcare workers, and immunocompromised people— those six months have arrived or will soon. While some of these folks may need to get a booster sometime soon, experts say there's no need to worry just yet.

Both the Centers for Disease Control and Prevention (CDC) and Food and Drug Administration (FDA), quickly put these concerns to rest by announcing that booster shots are not yet recommended at this time.

How Long Does Vaccine-Induced COVID-19 Immunity Last?

More data is still needed to determine how long immunity from these vaccines lasts. Real-time observation of the body's immune response is underway.

“We know that immunity lasts for at least six months, but most studies are starting to show that it could be much longer,” Nicholas Kman, MD, an emergency medicine physician at The Ohio State University Wexner Medical Center, tells Verywell. “For all the vaccine trials, the original participants continued to be studied for the duration of immunity and the early data looks good. We also know from infected healthcare worker studies early in the pandemic, that natural immunity could last as long as one year, so experts are optimistic that it could be more than a year.”

Is Waning Immunity A Concern?

“We do not have evidence of waning immunity,” William Moss, MD, executive director of the International Vaccine Access Center at the Johns Hopkins Bloomberg School of Public Health, tells Verywell. “Antibody levels to SARS-CoV-2 may decrease over time but this is expected. However, that does not mean people are then susceptible to COVID-19 as vaccinated individuals will quickly develop a strong memory immune response if re-exposed to the virus, and we also have cells that fight infection in addition to the antibodies.”

Antibody testing should not be used to assess the degree of protection provided by COVID-19 vaccines, according to the FDA. It is a tool utilized by healthcare providers to determine whether a patient was previously exposed to the virus, not for individuals to check whether their vaccine worked or not.

“Immune protection is conveyed by both specific antibody and cellular immunity responses,” Stanley H. Weiss, MD, an infectious and chronic disease epidemiologist and professor at the Rutgers New Jersey Medical School and the Rutgers School of Public Health, tells Verywell. “The levels of antibodies can wane far more quickly—and even be undetectable—whilst robust cellular immune protection and clinical protection both persist. In other words, even if specific antibody tests become non-detectable, the person may be protected.”

What This Means For You

Booster shots are not yet recommended at this time, but they may be soon. In the mean time, if you haven't gotten vaccinated, you can make an appointment at

Do We Need COVID-19 Booster Shots Now? 

With four variants of concern circulating in the U.S., especially the highly transmissible Delta variant, booster shots could be beneficial in the long run.

“The variants raise the issue of booster shots for the broader population,” Weiss says. “It will depend not only on the variants that have already been recognized and blossomed into becoming common. The COVID pandemic is raging in many parts of the world, and thus remains a breeding ground for new variants that have ‘survival’ advantages, especially higher transmissibility.”

According to Soumya Swaminathan, MD, chief scientist of the World Health Organization (WHO), there is no scientific evidence suggesting that boosters are necessary at this time. They may be needed in a year or two, but not six months after the first dose.

“Most experts expect that at some juncture, some booster/s will be needed,” Weiss says. “Here is what we know so far, general efficacy is likely much longer than 6 months. Think of it this way. First dose primes the immune system [and] affords some protection. A second dose boosts protection greatly.”

Booster doses may be needed if there is scientific evidence of waning immunity or a new virus strain is found to evade the immune protection offered by the current vaccines. However, there is no data backing this up yet.

“We may need booster shots, but not now,” Moss says. “I suspect we will see booster doses phased in, starting with vulnerable populations such as immunocompromised patients like solid organ transplant recipients and residents of long-term care facilities.”

People with weakened immune systems potentially develop a reduced immune response to COVID-19 vaccines, and according to Weiss, it’s possible that their immunity from COVID-19 vaccines will wane sooner.

“Vaccine efficacy in older persons and those with various reasons for imperfect immune systems were shown to be lower, often significantly lower, than in other adults,” he says. “Thus, an extra booster is usually recommended for these special populations. It would come as no surprise for that to now be true with all of the COVID vaccines. Limited studies so far are consistent with showing reduced efficacy in some of those special populations.”

This week Israel's Health Ministry announced plans to start a booster campaign for adults over 60 who received their second shot at least five months earlier. However, the CDC is still evaluating safety, efficacy, and benefit of boosters for this population.

What Should Vaccinated People Do in the Meantime?

Fully vaccinated individuals can still get COVID-19 because no vaccine is 100% effective. The vaccine may help prevent severe disease, but people with weaker immune systems remain vulnerable.

Experts recommend continuing to practice effective public health measures such as:

  • Wearing a face mask indoors
  • Avoiding indoor dining or social gatherings where masking isn’t possible
  • Practicing proper hand hygiene
  • Limiting potential exposures
  • Avoiding poorly ventilated spaces
  • Staying 6 feet away from other people

Earlier this week, the CDC updated their masking guidelines and recommended that fully vaccinated people wear masks in public indoor settings in areas where COVID-19 transmission is high. They also supported universal indoor masking for schools, no matter the vaccination status.

“If you are concerned about your immune status or are immunocompromised, the best thing you can do is continue to follow safe infection control guidance,” Kman says. “That said, it is especially important that close contacts of immunocompromised people aged 12 years and older should be vaccinated against COVID-19. In fact, given the rise in cases due to the delta variant, all eligible Americans should be vaccinated.”

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Pfizer. Pfizer and BioNTech Provide Update on Booster Program in Light of the Delta-Variant.

  2. Thomas SJ, Moreira Jr ED, Kitchin N, et al. Six Month Safety and Efficacy of the BNT162b2 mRNA COVID-19 Vaccine. medRxiv. 2021. doi:10.1101/2021.07.28.21261159

  3. Centers for Disease Control and Prevention. Joint CDC and FDA Statement on Vaccine Boosters.

  4. U.S. Food and Drug Administration. Antibody Testing Is Not Currently Recommended to Assess Immunity After COVID-19 Vaccination: FDA Safety Communication.

  5. World Health Organization. COVID-19 Virtual Press conference transcript - 12 July 2021.

  6. Centers for Disease Control and Prevention. Interim Clinical Considerations for Use of COVID-19 Vaccines Currently Authorized in the United States.

  7. Centers for Disease Control and Prevention. Interim Public Health Recommendations for Fully Vaccinated People.

By Carla Delgado
Carla M. Delgado is a health and culture writer based in the Philippines.