man wearing face mask

Updated Aug. 23, 2021

The Delta variant (B.1.617.2) has become the dominant form of SARS-CoV-2 spreading in the United States.

According to the Centers for Disease Control and Prevention (CDC), Delta made up more than 93% of new COVID-19 cases in the U.S. in the final two weeks of July.

With Delta spreading, it’s as important as ever to protect yourself against COVID-19. Below are answers to some frequently asked questions about the Delta variant and how to protect yourself.

Where Did the Delta Variant Come From?

Viruses change and mutate over time, causing variants. The Delta variant is just one of many variants of SARS-CoV-2.

The variant first emerged in India in late 2020 and quickly spread worldwide. It became the dominant variant in the U.S. in the summer of 2021. The CDC classifies Delta as a variant of concern, along with these other variants:

  • The Alpha variant (B.1.1.7).
  • The Beta variant (B.1.351).
  • The Gamma variant (P.1).

Graham Snyder, MD, medical director, Infection Prevention and Hospital Epidemiology, UPMC, says variants are common. The number of cases may vary because of factors like vaccination rates. And although Delta may fade over time, another variant could emerge.

“A future that I think is easy to predict, with most of the world unvaccinated by a long shot and with a lot of transmissions occurring, more variants are going to emerge,” Dr. Snyder says. “Delta won’t be the last.”

Is the Delta Variant More Contagious?

The Delta variant appears to be the most contagious variant yet.

A report by the Scientific Pandemic Influenza Group on Modelling, Operational (SPI-MO) sub-group said Delta was 40% to 60% more contagious than the Alpha variant. Delta is about twice as contagious as the original strain of SARS-CoV-2.

Along with Delta’s increased transmissibility, lowering of COVID-19 prevention tactics could be a factor in how quickly Delta is spreading.

“How much of this emergence is Delta being more contagious, and how much is human behavior giving it more opportunities?” Dr. Snyder says. “The answer is both.”

Does the Delta Variant Make You Sicker?

Some data suggests the Delta variant may cause more severe cases of COVID-19. However, scientists are still studying it.

“The verdict is still out on how much more likely it is to make people sick, including requiring hospitalization or death,” Dr. Snyder says.

Do Vaccines Work Against the Delta Variant?

Yes, vaccines still work. The vaccines are safe and effective against SARS-CoV-2 and its variants. They are especially effective in preventing severe illness, hospitalization, and death.

The best way to prevent COVID-19 infection is by getting vaccinated.

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Can I Still Get COVID-19 After Getting Vaccinated?

Yes.

No vaccine is 100% effective, meaning breakthrough infections are possible. Fully vaccinated people can still get COVID-19 and spread it to others.

Breakthrough infections are rare. The vaccines are still very effective against COVID-19, especially in preventing severe illness, hospitalization, and death.

“The vaccine is really safe. It’s highly effective,” Dr. Snyder says. “But that doesn’t mean it’s perfect protection. We’re going to see people get sick.”

Some people may not have a robust immune response to the vaccine. That includes people with immune systems compromised by medical conditions or organ transplants. However, anyone can get sick with COVID-19.

Some data suggests that people infected with the Delta variant may carry high viral loads, even if they’ve been vaccinated. That makes them highly contagious. But the vaccine may make you contagious for a shorter amount of time.

Dr. Snyder says if you start to feel symptoms of COVID-19, you should get tested as soon as possible. Also, treatments like monoclonal antibodies can help if you do get COVID-19.

Why Should I Get Vaccinated if I Can Still Get COVID-19?

Because the COVID-19 vaccine is still the best way to prevent COVID-19.

Although breakthrough infections are possible, they are rare. The vaccines are especially important in preventing severe illness, hospitalization, and death. Unvaccinated people account for the high majority of COVID-19 infections, severe cases, and deaths. If you are not fully vaccinated, you are more vulnerable to COVID-19.

“The vaccine doesn’t make you invincible, but the vaccine is effective and safe,” Dr. Snyder says. “It does really reduce your chances of becoming sick, and particularly it does well at preventing you from being hospitalized or potentially dying of COVID-19. That’s an important risk difference, even if you’re young and healthy.”

By getting vaccinated, you also can protect vulnerable people around you. That includes people with compromised immune systems and people who are not eligible yet for the vaccine.

Do I Need to Wear a Mask After I’m Fully Vaccinated?

In July 2021, the CDC updated its guidance for fully vaccinated people.

The CDC recommends people wear masks indoors in public in regions with high levels of COVID-19 transmission, even if they are fully vaccinated.

The CDC also recommends teachers, students, and visitors in K-12 schools wear facemasks, even if they’ve been fully vaccinated.  On Aug. 31, 2021, the Pennsylvania Department of Health mandated K-12 students, teachers, and staff wear masks inside schools beginning Sept. 7. 

You should wear a mask if required by law, rules, regulations, or local guidance, even once you’re fully vaccinated. Everyone who comes to a UPMC facility must wear a mask.

People who are not fully vaccinated should wear a mask in public indoors and in crowded outdoor areas. People who are immunocompromised, or who live with or care for someone who is, may want to consider wearing a mask in some situations.

The COVID-19 vaccine reduces the risk of serious complications of COVID-19 if you are exposed to the virus. And while the vaccine helps reduce the risk of person-to-person transmission, that’s not what it does best. Masking and physical distancing provide an important layer of protection from being exposed to the virus. Wearing a mask can lower the risk of COVID-19 spread significantly.

“Masking and distancing is a good layer of protection, just like the vaccine is a good layer of protection,” Dr. Snyder says. “Neither of them are perfect, but together, they’re really, really, really effective.”

Is It Safe to Travel With the Delta Variant Spreading?

Many people are taking part in activities that they didn’t do for the first year or so of the pandemic. That may include travel, gathering with family and friends, going to the movies, or attending sports games or concerts.

Dr. Snyder says you should consider the risk to you and your loved ones. There may be ways you can make your experience safer. Getting the vaccine is one important step, and masking and physical distancing is another.

Before taking part in an activity, consider factors like:

  • Air circulation. Outdoor activities are generally safer.
  • Who’s attending. Is everyone fully vaccinated?
  • How many people are attending. Generally speaking, more crowded activities are riskier.
  • How close people are. Is it possible to physically distance?
  • What the activity is. Are you expending a lot of air?

For activities that are riskier, taking extra precautions like masking and physical distancing can help lower your risk.

When Will the Vaccines Be Approved?

On Aug. 23, 2021, the Food and Drug Administration (FDA) approved the Pfizer-BioNTech COVID-19 vaccine for Americans 16 and older. The vaccine had previously been distributed under emergency use authorization (EUA). The Pfizer vaccine also is available to children age 12-15 under EUA.

Two other COVID-19 vaccines, developed by Moderna and Johnson & Johnson/Janssen, also are being distributed under EUA. Moderna has applied for full FDA approval.

An EUA is not the same as a full approval. But to receive an EUA, the vaccines must meet FDA standards for safety and effectiveness. The COVID-19 vaccines have exceeded those standards, Dr. Snyder says.

“We’re confident in the vaccines, even if we’re just now giving them under emergency use authorization, because we have so much experience and scrutiny of them,” Dr. Snyder says. “I think approval is just a matter of time. I think it’ll be affirmation that we’re all confident these are safe and effective.”

Will We Need a COVID-19 Booster Shot?

The COVID-19 vaccine manufacturers have raised the idea that a booster shot may be necessary in the future. However, people do not currently need a booster shot.

Dr. Snyder says factors that could determine a booster shot include:

  • A person with a weakened immune system that doesn’t respond to the initial vaccination series and could benefit from an additional dose.
  • Our immune system needs a “reminder” to be prepared after the response to the initial vaccination series wanes.
  • The virus has changed, and the vaccine hasn’t prepared our immune system to recognize the changing virus.

Data shows people with a weakened immune system who received an mRNA vaccine — Moderna or Pfizer — could benefit from an additional dose. The vaccines continue to work well against the Delta variant.

“So far, there’s no data that the vaccine is running out or their immune system is forgetting about how to be prepared,” Dr. Snyder says. “We don’t know how long your body will remember how to respond to COVID-19, but so far, that’s not a reason to get a booster.”

Immunocompromised people who did not have a strong response to the first dose(s) of vaccine could benefit from a booster. In accordance with updates from the FDA and CDC on Aug. 13, 2021, UPMC immediately started providing a third dose of the Pfizer or Moderna mRNA vaccines to immunocompromised individuals who received the first two doses of those vaccines.

On Aug. 18, 2021, the CDC and other U.S. health officials announced plans to make a third dose of the Pfizer and Moderna vaccines available to all Americans who had received the first two doses of those vaccines. A person would receive the third dose a minimum of eight months after their second dose.

At this time, UPMC is only providing third doses of the Pfizer and Moderna vaccines to immunocompromised people who have received the first two doses of those vaccines. There is no booster dose of the Johnson & Johnson/Janssen vaccine at this time. Please see Vaccine.UPMC.com for more details and to learn if you are eligible for a third dose.

Sources

American Society for Microbiology, How Dangerous Is the Delta Variant (B.1.617.2)? Link

Centers for Disease Control and Prevention, Delta Variant: What We Know About the Science. Link

Centers for Disease Control and Prevention, Understanding Variants. Link

Centers for Disease Control and Prevention, Variant Proportions. Link

Centers for Disease Control and Prevention, What You Need to Know About Variants. Link

Centers for Disease Control and Prevention, When You've Been Fully Vaccinated. Link

Scientific Pandemic Influenza Group on Modelling, Operational, SPI-M-O: Consensus Statement on COVID-19. Link

About UPMC

Headquartered in Pittsburgh, UPMC is a world-renowned health care provider and insurer. We operate 40 hospitals and 700 doctors’ offices and outpatient centers, with locations in central and western Pennsylvania, Maryland, New York, and internationally. We employ 4,900 physicians, and we are leaders in clinical care, groundbreaking research, and treatment breakthroughs. U.S. News & World Report consistently ranks UPMC Presbyterian Shadyside as one of the nation’s best hospitals in many specialties and ranks UPMC Children’s Hospital of Pittsburgh on its Honor Roll of America’s Best Children’s Hospitals.