What role do COVID-19 vaccinations play in helping to curb the pandemic?

COVID-19 vaccination will help protect ourselves, our loved ones, and our communities from the disease and save lives. Vaccines can both prevent and reduce the severity of disease. Vaccines provide immunity without the serious risks associated with getting infected naturally. Wearing masks and physical distancing help reduce the chance of being exposed to the virus or spreading it to others, but these measures are not enough.

The COVID-19 vaccines are designed to work with our immune system so the body is ready to fight the virus if we are exposed to it. When enough people in a community get vaccinated against COVID-19, immunity rates in our communities substantially increase, which reduces the spread of the virus.

Are the COVID-19 vaccines safe?

Yes. COVID-19 vaccines have been evaluated in tens of thousands of individuals who volunteered to participate in clinical trials. These clinical trials met the same rigorous standards set for all vaccines by the Food and Drug Administration (FDA).


The information from these clinical trials allowed the FDA to determine that the newly authorized COVID-19 vaccines meet its safety and effectiveness standards. Based on these findings, the FDA has made the vaccines available for use in the United States under what is known as an Emergency Use Authorization (EUA).


Millions of people in the United States and around the world have received COVID-19 vaccines. COVID-19 vaccines have undergone the most intensive safety monitoring in U.S. history.


Results from U.S. and global safety monitoring efforts are excellent. There are rigorous systems in place to quickly identify any safety concerns and take action.


How effective are the vaccines for disease prevention?

The COVID-19 vaccines currently authorized for use were found to be highly effective in preventing COVID-19 in clinical trials.

All authorized COVID-19 vaccines have high efficacy in protecting against severe COVID-19 disease as well as COVID-19 related hospitalizations and death. They all have been reviewed rigorously by the scientific experts and have met the FDA efficacy standards for emergency use authorization.

How do COVID-19 mRNA vaccines (Pfizer and Moderna) work?

The vaccines contain synthetic mRNA, which is genetic information used to make the SARS-CoV-2 spike protein. The spike protein is the part of the virus that attaches to human cells. The spike protein alone cannot cause COVID-19.

Once the spike protein is created, it causes the immune system to make antibodies against the virus. These antibodies can then provide protection if a person comes into contact with the virus.

Since the vaccine does not contain any virus, it is not possible to spread COVID-19 from receiving the vaccine. The mRNA does not enter the center of the human cell where DNA is made (the nucleus); so, it cannot alter the genetic material of the cell (DNA). The mRNA is rapidly broken down, making the chance for long-term side effects less likely. The mRNA vaccines do not have the ability to cause cancer.

Learn more here: https://www.cdc.gov/vaccines/covid-19/downloads/healthcare-professionals-mRNA.pdf

How do COVID-19 viral vector vaccines (Johnson & Johnson's Janssen vaccine) work?

The J&J/Janssen COVID-19 vaccine contains an inactivated "common cold" virus called an adenovirus. This virus cannot replicate in the human body, will not cause an infection, and does not enter DNA. The adenovirus carries a gene for the coronavirus spike protein that allows it to be created and recognized by the immune system. The spike protein is the part of the coronavirus that attaches to human cells. The spike protein alone cannot cause COVID-19. Once the spike protein is created it causes the immune system to make antibodies against the virus. These antibodies can the provide protection if a person comes into contact with the coronavirus.

What are the updates on the use of the Johnson & Johnson/Janssen vaccine?

On April 12, 2021, out of an abundance of caution, FDA recommended pausing use of the vaccine. April 23, the CDC and FDA recommended to resume the use of the Johnson & Johnson/Janssen vaccine after further investigation and outreach prompted lifting the temporary pause. Like with all vaccines, people should be aware of the risks & benefits. While serious, the risk of thrombocytopenia syndrome (TTS, a rare blood clot associated with low platelets count) is still considered to be rare.

Individuals who receive the Johnson & Johnson/Janssen vaccine should monitor for the following symptoms for 3 weeks after they receive the vaccine.

If any of these symptoms develop within 3 weeks of receiving the Johnson & Johnson/Janssen vaccine, seek medical care right away.

Experts believe that people with risk factors for blood clots, or prior history of blood clots that were not associated with low platelets, are not at an increased risk of TTS. Additionally they state pregnancy and oral contraceptives do not make people more likely to develop TTS. People who take aspirin or anticoagulants as part of their routine medications may continue them prior to receiving the Janssen vaccine. The American Society of Hematology has published recommendations regards diagnosis and treatment of TTS which can be found at this link:  https://www.hematology.org/covid-19/vaccine-induced-immune-thrombotic-thrombocytopenia

Those who are concerned about their risk of TTS from the Johnson & Johnson/Janssen vaccine could consider an mRNA COVID-19 vaccine, and anyone with concerns is encouraged to discuss them with a healthcare provider.


Can I get COVID-19 from a vaccine?

No. None of the COVID-19 vaccines currently authorized for use or in development in the United States can give anyone COVID-19.

What many people experience as a result of receiving the vaccine are the body’s immune system responding to the COVID-19 vaccine. All of the COVID-19 vaccines work with your immune system so it will be ready to fight the virus if you are exposed. Common immune responses are pain, redness, and swelling in the arm of the injection, along with possible tiredness, headache, muscle pain, chills, fever, and nausea.

It usually takes a few weeks for the body to build immunity after being fully vaccinated (that is, two doses for Pfizer and Moderna or one dose for Johnson & Johnson/Janssen). That means it is possible for an individual to be infected with the virus that causes COVID-19 if exposed just before or just after vaccination. The vaccine itself does not cause infection. Similarly, the vaccine cannot cause you to have a positive COVID-19 test.

What are 'variants' and what do they mean for individuals considering vaccination?


Viruses constantly change through mutation, and new variants (or strains) of a virus occur over time. Sometimes new variants emerge and disappear. Other times, new variants emerge and stay. Multiple variants of the virus that causes COVID-19 have been documented in the United States and globally during this pandemic. Scientists are studying these variants to understand whether they:



Preliminary data is showing that COVID-19 vaccines are effective at preventing severe disease, hospitalization, and death in relation to many common variants. Current public health actions such as wearing a mask, staying at least 6 feet apart, avoiding crowds, and getting vaccinated when it is available combined are the best protection against variants of the virus that causes COVID-19.


For more information on variants of concern please visit: https://www.cdc.gov/coronavirus/2019-ncov/variants/index.html.


What is an Emergency Use Authorization (EUA)?

During a public health emergency, the FDA can use a process called 'Emergency Use Authorization' (EUA). This process allows the use of medical products that are not yet approved to diagnose, treat, or prevent serious or life-threatening diseases when certain criteria are met.

Several additional COVID-19 vaccines are currently being developed and tested for their safety and effectiveness in clinical trials (efficacy). Once vaccine manufacturers submit for authorization, the FDA evaluates the EUA request and determines whether they are safe and effective, taking scientific evidence into account. For a vaccine to receive an EUA, the FDA must determine if the vaccine's benefits outweigh its risks based on data from rigorous clinical trial(s).

Additional information on EUAs: https://www.fda.gov/vaccines-blood-biologics/vaccines/emergency-use-authorization-vaccines-explained

How does the FDA Assess Safety and Effectiveness of a COVID-19 Vaccine Submitted for Emergency Use Authorization (EUA)?

COVID-19 vaccines are undergoing a rigorous development process that includes tens of thousands of study participants to gather required safety and efficacy data, in the same way as many other currently approved vaccines. The FDA evaluates the information submitted by a vaccine manufacturer and uses all available tools and information, including records reviews, site visits, and previous manufacturing compliance history.

For an EUA to be issued, the FDA must determine that the known and potential benefits outweigh the known and potential risks of the vaccine.

Link: https://www.fda.gov/vaccines-blood-biologics/vaccines/emergency-use-authorization-vaccines-explained

Which COVID-19 vaccines have been authorized for use by the FDA?

At this time, there are three COVID-19 vaccines authorized for use by the FDA. The Pfizer-BioNTech mRNA COVID-19 vaccine received FDA authorization December 11, 2020 for individuals ages 16 and older. An amendment on May 10, 2021 authorized use for individuals ages 12 and older. It is a 2-dose vaccination series, given intramuscularly, recommended at least 3 weeks apart. For the full FDA statement on the authorization of this vaccine: https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-fda-authorizes-pfizer-biontech-covid-19-vaccine-emergency-use

The Moderna mRNA COVID-19 vaccine received FDA authorization December 18, 2020 for individuals 18 and older. It is a 2-dose vaccination series, given intramuscularly, recommended at least 1 month apart. For the full FDA statement on the authorization of this vaccine: https://www.fda.gov/news-events/press-announcements/fda-takes-additional-action-fight-against-covid-19-issuing-emergency-use-authorization-second-covid

Johnson & Johnson's Janssen vaccine received FDA authorization February 27, 2021 for individuals ages 18 and older. After the EUA was granted for the Johnson & Johnson/Janssen vaccine, reports of rare adverse events prompted a brief and temporary pause in administration April 12-23, 2021. By April 21, nearly 8 million doses of the Johnson & Johnson/Janssen COVID-19 vaccine had been administered. Safety monitoring found that 97% of reported reactions after vaccination were not serious. Please see Johnson & Johnson/Janssen vaccine updates above for more information; therefore recommendations for use of the vaccine in those older than 18 years was reinstated. It is a 1-dose vaccination, injected into the muscle, typically of the upper arm. For the full FDA statement on the authorization of this vaccine: https://www.fda.gov/news-events/press-announcements/fda-issues-emergency-use-authorization-third-covid-19-vaccine

Why have vaccines been developed so quickly?

The vaccine process has happened faster because vaccine research and development, clinical trials, manufacturing, and plans for distribution have occurred at the same time. This method removed delays that occur when these processes are carried out one after the other. Steps to ensure safety were NOT eliminated.


What can individuals do to protect themselves and others during the pandemic?

It is vital that each person uses all tools available to stop the pandemic. Tools include:

Why do we need a vaccine if we can take other COVID-19 precautions, like masking and physical distancing, to slow or prevent the spread?

It is vital that each person uses all tools available to stop the pandemic. Vaccines work with the immune system and allow a strengthened response to the virus if exposed.

Other steps, like covering the mouth and nose with masks/face coverings worn properly, washing hands, and staying at least 6 feet away from others, help reduce chances of exposure to the virus or spreading it to others.

Together, COVID-19 vaccination and following recommendations for self-protection and to protect others will offer the best prevention for further spread of COVID-19. For more information: https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/prevention.html