COVID-19 vaccine FAQs – University of Dayton – News Home

How effective are the vaccines at preventing laboratory-confirmed COVID-19 illness? 

In phase 3 clinical trials, the Pfizer-BioNTech vaccine was 95% effective against contracting symptomatic COVID-19. The Moderna vaccine was 94% effective against contracting symptomatic COVID-19. The Johnson & Johnson Janssen vaccine was 85% effective against contracting symptomatic COVID-19. All vaccines have proven to be close to 100% effective in preventing severe illness and death attributable to COVID-19. Learn more about how COVID-19 vaccines work. 

How and when can I get a vaccine? 

Visit to search for providers vaccinating in the current phase by county and ZIP code, and also for the State of Ohio’s current criteria regarding who is eligible for the vaccine. 

What does the Catholic Church say about getting a COVID-19 vaccine? 

In speaking about the Moderna and Pfizer COVID-19 vaccines, Pope Francis said: “I believe that ethically everyone must take the vaccine. It is not an option; it is an ethical action, because you are playing with your health, you are playing with your life, but you are also playing with the lives of others.” The Vatican’s doctrinal office also has said it is morally acceptable for Catholics to take the vaccines. Additional guidance comes from the U.S. Conference of Catholic Bishops, which has stated that receiving the COVID-19 vaccine “ought to be understood as an act of charity toward the other members of our community. In this way, being vaccinated safely against COVID-19 should be considered an act of love of our neighbor and part of our moral responsibility for the common good.” 

Can a COVID-19 vaccine make me sick with COVID-19? 

None of the emergency use authorized and recommended COVID-19 vaccines or COVID-19 vaccines in development in the United States contains the live virus that causes COVID-19, so a COVID-19 vaccine cannot make you sick with COVID-19. However, some vaccinations may result in symptoms similar to COVID-19. These symptoms are a result of the vaccine teaching the immune system how to recognize and fight the virus, and are a sign the body is building protection against the virus that causes COVID-19. It also is possible to be exposed and develop COVID-19 illness shortly after vaccination and before your body develops protective antibodies. Learn more about how COVID-19 vaccines work.  

What are side effects of the vaccine?

You may have mild side effects, including soreness or redness at the injection site. Other common short-term side effects are fever, chills, headache, tiredness and muscle or joint pain. These side effects are normal as your body creates an immune response to protect you from COVID-19, and may increase with the second dose. Individuals who were infected with COVID-19 may experience some of these symptoms after the first vaccine dose. Learn more about what to expect in this video from the CDC. 

How long will it take for the vaccination to take effect? 

It typically takes a few weeks for the body to build protection against the virus that causes COVID-19 after vaccination. So it is possible someone could be infected with COVID-19 just before or just after vaccination and still get sick with the virus before you are fully immune.  

Will the vaccine protect against the new COVID-19 variants now confirmed in the U.S.? 

According to the CDC, scientists are working to learn more about how easily variants might spread. Researchers and public health officials are studying whether variants spread more easily person-to-person, cause milder or more severe disease in people, are detected by viral tests, respond to medicines used to treat people for COVID-19, and/or change the effectiveness of COVID-19 vaccines.

The CDC’s recommendations for slowing the spread of COVID-19 — wearing masks, staying at least 6 feet apart from others, avoiding crowds, ventilating indoor spaces, and washing hands often — also will also help prevent the spread of variants.

After getting a COVID-19 vaccine, will I test positive for COVID-19 on a viral test? 

Neither the authorized and recommended vaccines nor the other COVID-19 vaccines in clinical trials in the United States should cause you to test positive on viral tests, which assess whether you have a current infection.​ However, you may test positive on some antibody tests, which indicate you had a previous infection and may have some level of protection against the virus. Experts are looking at how COVID-19 vaccination may affect antibody testing results. 

If I had COVID-19 and recovered, do I still need to get vaccinated with a COVID-19 vaccine? 

Yes, because of the severe health risks associated with COVID-19 and because reinfection with COVID-19 is possible. Plus, experts are unsure about how long someone who had COVID-19 will have natural immunity. The CDC is providing recommendations to federal, state and local governments about who should be vaccinated first. 

Will a COVID-19 vaccine alter my DNA? 

COVID-19 mRNA vaccines do not change or interact with your DNA in any way. Learn more about how COVID-19 mRNA vaccines work. 

Is it safe for me to get a COVID-19 vaccine if I am planning to be pregnant, already pregnant, breastfeeding or planning to get a screening mammogram?  

According to the CDC, based on current knowledge, experts believe COVID-19 vaccines are unlikely to pose a risk to a person trying to become pregnant in the short or long term. Furthermore, the CDC adds there is no evidence antibodies formed from COVID-19 vaccination cause any problems with pregnancy, including the development of the placenta. In addition, there is no evidence suggesting fertility problems are a side effect of ANY vaccine. People who are trying to become pregnant now or who plan to try in the future may receive the COVID-19 vaccine when it becomes available to them. Pregnant women have a higher risk of complications from COVID-19, so they are advised to discuss vaccination with their obstetrician.

The CDC also states mRNA vaccines are not thought to be a risk to the breastfeeding infant. People who are breastfeeding and are part of a group recommended to receive a COVID-19 vaccine, such as healthcare personnel, may choose to be vaccinated.

If you are planning to get a screening mammogram soon, you may wish to schedule that with the timing of the second dose of your vaccine in mind. Some experts recommend waiting until six weeks after the second vaccine dose. Consider consulting with your physician for more insight.  

Additional information can be found at the bottom of the CDC’s “Myths and Facts about COVID-19 Vaccines” page and the CDC’s “Vaccination Considerations for People who are Pregnant or Breastfeeding,” plus by consulting with your primary care physician or specialist.

What are the ingredients in the COVID-19 vaccine?

The COVID-19 vaccines available in the United States do not contain eggs, preservatives or latex. For a full list of ingredients, please see each vaccine’s fact sheet for recipients and caregivers: 

How are UD employees being compensated for time off to receive the vaccine?

Employees should use sick time to get the vaccine, as well as for time taken because of an adverse reaction to the vaccine. Similar to reporting for a COVID-19 illness, report your sick time as you normally would and then contact Beth Schwartz, director of UD’s benefits and wellness program, to replenish your charged sick time. UD employees should use this form to report they’ve received their full COVID-19 vaccination and upload their vaccination record; this form needs to be completed to replenish your sick time.

Were minorities or people with high-risk health conditions included in the clinical studies?

Yes. Approximately 42% of participants in Pfizer BioNTech’s worldwide clinical trials, 37% of the Moderna study population, and 26% of the participants in Johnson & Johnson’s study were from minority communities, which is similar to the diversity of the U.S. at large. In addition, clinical studies included participants age 65 and older (21% of Pfizer-BioNTech participants; 23% of Moderna participants) or 60 and older (34% of Johnson & Johnson participants); and those with high-risk chronic diseases, such as diabetes, severe obesity and cardiac disease (46% of Pfizer-BioNTech participants; 42% of Moderna participants; 41% of Johnson & Johnson participants).

If I received the vaccine, do I still need to quarantine after a COVID-19 exposure? 

Vaccinated persons who have been exposed to someone with suspected or confirmed COVID-19 are not required to quarantine if they meet all of the following criteria:

  • Are fully vaccinated (i.e., more than 2 weeks following your final dose of a one- or two-dose series).
  • Are within 3 months following receipt of the last dose in the series.
  • Have remained asymptomatic since the current COVID-19 exposure.

Persons who do not meet the above criteria should continue to follow UD quarantine guidance after exposure to someone with suspected or confirmed COVID-19 and must report their close contacts on the University’s COVID-19 health reporting page.

For more info, please visit the “Public health recommendations for vaccinated persons” section on this page.

Do I need to wear a mask if I have received the vaccine?  

Yes, to protect yourself and others, it will remain necessary after receiving the vaccine to continue following CDC and public health guidelines, which include wearing a face covering over your nose and mouth, staying at least six feet away from others, avoiding large gatherings and poorly ventilated spaces, and washing your hands often. 

It’s important for everyone to continue using all the protective tools available as we learn more about how COVID-19 vaccines work in real-world conditions. Experts are looking at how many people get vaccinated and how the virus is spreading in communities. Experts also do not yet know whether getting a COVID-19 vaccine will prevent you from spreading the virus that causes COVID-19 to other people, even if you do not get sick yourself. The CDC will continue to update this page as it learns more.

How can I report my vaccine record to the University? 

UD students and employees should use this form to report they’ve received their full COVID-19 vaccination and upload their vaccination record.

When will the University provide the vaccine to students, faculty and staff?

The University is an enrolled provider and will provide the vaccine when it becomes available to the University from the State of Ohio. Visit Ohio’s COVID-19 Vaccine Distribution page for more information.

I am a UD student and have received the COVID-19 vaccine. Do I still need to participate in the University’s surveillance testing? 

Yes. We will continue conducting surveillance testing in accordance with guidance from the Ohio Department of Health on surveillance testing for higher education.  

Will the University require students, faculty and staff to have the COVID-19 vaccine?  

The University highly recommends students, faculty and staff receive the vaccine.

Where can I find more information about COVID-19 vaccines?

Please consult the Centers for Disease Control and Prevention “Myths and Facts about COVID-19 Vaccines” page and the CDC “Frequently Asked Questions about COVID-19 Vaccination” page.