The Centers for Disease Control and Prevention’s (CDC) recent recommendation that those who are fully vaccinated against COVID-19 can shed their masks and drop social distancing in many public situations was a bridge too far for some critics.

The general upshot is that the CDC should have waited until more of the population was vaccinated before relaxing basic infection control measures. As of a May 28, 2021, update, the CDC recommended that fully vaccinated people can “resume activities without wearing masks or physically distancing, except where required by federal, state, local, tribal, or territorial laws, rules and regulations, including local business and workplace guidance.”1

A CDC chart on activities shows that unvaccinated people should wear masks to “attend a crowded, outdoor event, like a live performance, parade, or sports event.”2 Vaccinated people can attend such events unmasked, as well as go to bars and restaurants where the unvaccinated should be masked, the CDC chart indicates.

With the mask issue politicized early in the pandemic and many now declining vaccinations, some question if the recommendation assumes a level of public trust that generally has not been apparent.

“I think part of the calculation in liberalizing the social distancing and masking recommendations was to kind of incentivize vaccination,” Melanie Swift, MD, MPH, occupational medicine specialist at the Mayo Clinic, said at a recent webinar.3 “It’s a bit optimistic to think that the same people who have refused to be vaccinated will comply with masking on the honor system.”

In wanting to convey a message of progress and optimism while rewarding and encouraging vaccination, the CDC seemed to some critics to be suggesting the pandemic was over.

The Infectious Diseases Society of America and an organization of human immunodeficiency virus (HIV) physicians said in a statement that the “CDC recommendations should not send the message that the pandemic is over … [W]e support the CDC recommendations, which are based on the latest scientific evidence.

“We also emphasize that the recommendations make no change to mask-wearing guidance in healthcare settings, schools, and public high-traffic areas including airports, as well as on airplanes, buses, and other forms of public transportation. Less than half of the U.S. population is fully immunized. Increased vaccinations will be necessary to control and finally end the pandemic.”4

Lawrence Gostin, JD, a professor at Georgetown University Law Center in Washington, DC, said in an emailed statement “the CDC is in an impossible position facing intense pressure to loosen its guidance on masking and distancing for vaccinated people. It has now lurched from over-caution to abandoning caution.”

The problem, pointed out by many others, is “it’s still impossible to know who is fully vaccinated and who isn’t, and it’s unlikely that only those fully vaccinated will return to normal activities,” Gostin said. “The public will not feel comfortable in a crowded indoor space if they are unsure if the maskless person standing next to them is or is not vaccinated. The U.S. has no ‘proof of vaccination’ system, and the Biden administration refuses to support such a system of verification.”

Breakthrough Infections

Beyond that unknown, there is the rare but real risk of breakthrough infection in the fully vaccinated. The COVID-19 vaccines, particularly the two mRNA shots, are highly effective but not perfect. Preliminary results from an ongoing multisite case-control study of healthcare workers in 25 states indicate the two mRNA COVID-19 vaccines are 94% effective in real-world conditions involving work and the community, the CDC reported.5

The overall study was not designed to measure vaccine breakthrough infection rates, but some results show it did occur, says lead investigator Tamara Pilishvili, PhD, an epidemiologist at the CDC National Center for Immunization and Respiratory Diseases.

“Breakthrough infections defined in our study as symptomatic healthcare personnel testing positive for SARS-CoV-2 more than seven days after the receipt of the second dose of the vaccine were rare,” she says. “During the study period of January through March 2021, we detected 19 [3%] breakthrough infections among healthcare personnel out of a total of 623 case-patients enrolled.”

The CDC also reported a total of 10,262 SARS-CoV-2 vaccine breakthrough infections recently from 46 U.S. states and territories as of April 30, 2021.

“Even though FDA (Food and Drug Administration)-authorized vaccines are highly effective, breakthrough cases are expected, especially before population immunity reaches sufficient levels to further decrease transmission,” the CDC reported.6 “However, vaccine breakthrough infections occur in only a small fraction of all vaccinated persons and account for a small percentage of all COVID-19 cases.”

Consider Local Situation

Another consideration is that some communities may not have enough vaccine supply, have many locals who refuse immunization, or are experiencing spikes in COVID-19 infections.

“Masking should remain in place. The local situation is going to be imperative,” said Christie Alexander, MD, associate professor at Florida State University College of Medicine said at the webinar.3

“I think [the CDC guideline] is based on science, but we can’t look at science in a vacuum,” she said. “In some communities, people should probably continue to wear masks. It has to be individualized in a sense that way.”

Unfortunately, the “blanket statement” will be heard differently by various groups, including those who probably were not vaccinated and wore masks as little as possible.

“I have recently been reading some articles about how those who aren’t vaccinated are like, ‘Oh, great. We don’t have to wear masks now,’ Alexander said. “That’s where it gets really tricky because we’re not going to be wearing armbands that say you’re vaccinated. It’s going to get really difficult in that regard.”

The irony, of course, could be those who are vaccinated — particularly the elderly and the immune-compromised who may not have mustered a full immune response — will be more likely to still wear masks around those they do not know.

Given all this, the CDC did the best it could in a difficult situation with the strong incoming vaccine efficacy data and some realpolitik demands to let the vaccinated go without masks, says William Schaffner, MD, a nationally known vaccine expert and professor at Vanderbilt University School of Medicine.

“I had the impression that [the] CDC had a fair number of suggestions [for the recommendation] from the field in public health and infectious diseases,” he says. “They thought that the effectiveness of this vaccine was so good, and cases now were coming down. The country had to move in that direction.”

CDC Director Rochelle Walensky, MD, certainly heard that message in a recent appearance before Congress, he says.

“They were saying that you have to move forward,” Schaffner says, adding the most frequent question public health officials and clinicians are asked by those who are fully vaccinated is “What can I do now that I could not do previously?”

“We needed to provide some reward for people who are vaccinated,” Schaffner says. “Does that mean all the problems go away? Of course not. There will be some rascals — people who are unvaccinated but take off their masks. We will just have to live with that.”


  1. Centers for Disease Control and Prevention. Interim public health recommendations for fully vaccinated people. Summary of recent changes. Updated May 28, 2021.
  2. Centers for Disease Control and Prevention. Choosing safer activities. Updated May 28, 2021.
  3. Newswise. How to win over vaccine skeptics: Live expert panel for May 20. May 21, 2021.
  4. Alexander BD, Gandhi RT. IDSA and HIVMA respond to new CDC masking guidance for fully vaccinated people. HIV Medicine Association. May 17, 2021.
  5. Pilishvili T, Fleming-Dutra KE, Farrar JL, et al. Interim estimates of vaccine effectiveness of Pfizer-BioNTech and Moderna COVID-19 vaccines among health care personnel — 33 U.S. sites, January-March 2021. MMWR Morb Mortal Wkly Rep 2021;70:753-758.
  6. CDC COVID-19 Vaccine Breakthrough Case Investigations Team. COVID-19 vaccine breakthrough infections reported to CDC — United States, January 1-April 30, 2021. MMWR Morb Mortal Wkly Rep 2021;70:792-793.