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Vaccines, Variants and Booster Shots

Breaking News

8.25.2021: The U.S. Food and Drug Administration officially approved use of the Pfizer-BioNTech vaccine for the prevention of COVID-19 for people age 16 and older on Monday, Aug. 23, 2021. The long-awaited decision opens the door for public and private organizations to implement vaccine mandates. It also resolves one of the major concerns mentioned by individuals hesitant to get any of the COVID-19 vaccines offered in the United States because none of them had been officially approved for use. The FDA had provided emergency use authorization for the Pfizer, Moderna and Johnson & Johnson vaccines but official authorization is a more complicated and time-consuming review process. FDA official authorization review remains ongoing for both the Moderna and Johnson & Johnson vaccines. The Pfizer vaccine continues to be available under emergency use authorization for individuals age 12 through 15 years of age and for the administration of a third dose in certain immunocompromised individuals.


While masking and physical distancing is important, vaccines are still the most effective deterrent for protection against COVID-19 and the potential for COVID-related severe illness and death. Not only will vaccines protect you from getting COVID-19, they will keep you from getting severely ill even if you happen to get COVID-19. (Because the vaccine takes 2-4 weeks to reach full effectiveness, there are instances where individuals have tested positive for COVID-19 because of exposure prior to or during the vaccination period.)

COVID-19 vaccines are scientifically proven to be safe and effective. Close to 190 million people – or 57 percent of the U.S. population - have received at least one dose of a COVID-19 vaccine in the United States as of August 20, 2021, according to the CDC. Nearly 164 million – or 49 percent of the total U.S. population – are fully vaccinated.

COVID-19 vaccines have undergone the most rigorous scientific safety testing in U.S. history. None of the COVID-19 vaccines contain live coronavirus and none of the vaccines can give you COVID-19.

The CDC advises everyone 12 years of age and older should get fully vaccinated against COVID-19 as soon as possible. The vaccines are free and do not require a doctor’s prescription.


Since its introduction in the United States, the SARS-CoV-2 virus which causes COVID-19 has been constantly replicating itself with each new infection. This repeated replication has led to the emergence of several new and genetically different variants of COVID-19, including the highly contagious Delta variant which is currently the predominant strain in the United States. For more information about Delta and other COVID-19 variants visit our COVID-19 variants page.

Booster Shots

The U.S. Department of Health and Human Services (HHS) announced on Aug. 18 that COVID-19 booster shots will become available in the United States this fall, and perhaps as early as Sept. 20, 2021. These shots are necessary, health officials say, because data is showing that the protection offered by initial doses of COVID-19 vaccines is starting to lessen. It is hoped that a third shot or booster shot will strengthen immune systems and continue to protect people against COVID-19 and its variants.

Booster shots will be available first to high-risk populations such as the elderly, those in long-term care and health care workers. Individuals become eligible for a booster shot 8 months after they receive their second dose of either the Pfizer or Moderna COVID-19 vaccine. The CDC is expected to recommend that people get the same brand vaccine for their booster shot as their initial vaccine. A doctor’s prescription is not needed to get a booster shot. Health officials are still gathering data regarding the possible need for a booster shot for those who received the single dose Janssen Johnson & Johnson vaccine and no guidance has been issued.

On Aug. 25, 2021, Johnson & Johnson reported that in a trial study, booster shots of its single-dose coronavirus vaccine generated a significant spike in antibodies that increased the body’s protection against infection. This is according to data collected in Phase 2 clinical studies in the U.S. and Europe, the company said. Booster shots of the J&J vaccine increased antibodies nine-fold higher than 28 days after the first shot, the company said. The U.S. FDA continues to review the data and had not made a decision on a J&J booster shot as of Aug. 25, 2021.

What vaccines are available?

There are currently three vaccines available to prevent COVID-19. All are proven to prevent COVID-19 by strengthening your immune system to fight off disease.

To date serious effects associated with the vaccines are extremely rare. The vaccines are intended to prevent people from getting sick, being hospitalized or potentially dying from COVID-19.

Details about the Vaccines

  • Two Doses (primer followed by booster shot 21 days later)
  • 95% protection against symptomatic COVID-19 after two doses
  • Uses mRNA to deliver a genetic code that allows your body to develop antibodies against the virus that causes COVID-19.
  • Authorized for: People 12 years and older
  • Peak Immunity: 7 days after second dose
Johnson & Johnson
  • The CDC and FDA recommended a pause in the use of Johnson & Johnson’s Janssen COVID-19 Vaccine in the United States out of an abundance of caution, effective Tuesday, April 13. However, on April 23, both organizations lifted their pause recommendations. In addition, the CDC reported on April 30 that some of the adverse reactions to the vaccine may have been brought on by anxiety. People who have received the J&J/Janssen COVID-19 vaccine within the past three weeks who develop severe headache, abdominal pain, leg pain or shortness of breath should seek medical care right away.
  • One Dose
  • 72% protection against moderate and severe COVID-19, 85% protective rate against severe disease.
  • Uses a harmless adenovirus vector to deliver a key COVID-19 virus protein. This foreign protein makes your immune system react and build defenses against COVID-19.
  • Authorized for: People 18 years and older
  • Peak Immunity: 14-28 days after single dose
  • Two Doses (primer followed by booster shot 28 days later)
  • 94.1% protection against symptomatic COVID-19 after two doses; likely higher protection from severe disease, hospitalization and death
  • Uses mRNA to deliver a genetic code that allows your body to develop antibodies against the virus that causes COVID-19
  • Authorized for: People 18 years and older
  • Peak Immunity: 14 days after second dose