COVID-19 Vaccine FAQs

About Vaccines

What is a vaccine?

According to the CDC, a vaccine stimulates your immune system to produce antibodies and cellular immunity to combat that specific disease, like it would if you were actually exposed to the infection. After getting vaccinated, you develop immunity to that infectious agent without having to get the disease first. This is why vaccines are so important — they prevent disease by letting you develop immunity in a safe and controlled way.

What is the difference between vaccine response and a vaccine reaction?

Vaccines are intended to produce active immunity to specific antigens (viral or bacterial components). An immune response is how the body recognizes the vaccine and builds up immunity through antibody production. It is typical for this process to induce soreness at the injection site, headaches, muscle aches, fever and mild flu-like symptoms. Some people experience redness, warmth and itching over or near the injection site as a delayed reaction, typically 5 to 14 days after the shot. These symptoms may last from a few hours to a few days, but they should not stop you from receiving your second dose. It is recommended that you take ibuprofen or acetaminophen to help alleviate any such side effects following vaccination. The COVID-19 vaccines from Pfizer and Moderna will likely generate a stronger immune response than other vaccines.

Different from a vaccine response, vaccine reactions are undesired effects that are much less frequent. These allergic reactions are a common concern for vaccine providers due to severity, but they are very rare in occurrence. Anaphylaxis following vaccines can occur within minutes of the vaccination, in approximately one in one million doses for many vaccines. This is why we ask everyone to stay for observation for at least 15 minutes after their vaccine is administered.

About COVID-19 Vaccine

How does the vaccine for COVID-19 work?

Pfizer and Moderna’s vaccines use novel messenger-RNA, or mRNA, technology, which uses genetic material which causes the body to create a protein or antibody directed toward the virus. The immune system then recognizes the virus and attacks it. The Pfizer study has enrolled 43,538 volunteers and Moderna 30,000 volunteers. In late-stage clinical trials, 50% of the volunteers got the vaccine, while the other half got a placebo of saltwater. Then they waited to see who would get sick with COVID. An independent board of experts looked at the placebo and vaccine participants and reported that both vaccines are 95% effective.

Is it safe?

The safety and efficacy of the vaccines is reviewed by panels of independent experts retained by the companies; by FDA scientific staff; and by an independent panel of experts convened by the FDA prior to any vaccine being granted EUA. Currently, all available data suggests these vaccines are safe. We await the results of the FDA EUA process for further clarification of side effects. As part of the EUA process all individuals receiving the vaccine will receive a fact sheet. The CDC and the FDA will continue to monitor individuals who have received the vaccine to ensure there’s no evidence of even rare safety issues.

Can I get COVID-19 from the vaccine?

No, it is not possible to get COVID-19 from vaccines. The Pfizer and Moderna vaccines use a genetic code that mimics the virus, while other vaccines being studied use inactivated virus or other methodology. None of these can cause COVID-19.

Will it keep me from getting COVID-19?

Current data shows that both the Pfizer vaccine and Moderna vaccines are 95% effective in preventing an individual from getting COVID-19. The studies did not test everyone to see how many people in the vaccinated group got infected compared with the placebo group. Instead, the scientists compared how many in the vaccinated group and the placebo group went on to develop the disease.

Are there other vaccines being studied?

Other manufacturers are all working on vaccines that use different technology to activate the immune system against COVID-19. Click to view the vaccine tracker.

How long will it take for the vaccine to begin protecting me?

It normally takes about two to three weeks after the second dose for cellular immunity to develop and several weeks for a full antibody response.

Are there challenges with the distribution?

These vaccines will require two doses and the Pfizer vaccine must be kept at very low temperatures — much colder than a household freezer. Many hospitals and clinics do not have the ability to store the medicine at these ultra-low temperatures. Owensboro Health does have this type of equipment available and is able to store and distribute the Pfizer or Moderna vaccine. During the distribution of vaccines, we will need to keep the vaccines closely temperature controlled and monitored. While this adds to the complexity of distribution of the vaccine, Owensboro Health has dedicated teams that have worked on the logistics to store and safely distribute the vaccines we receive.

Is this an annual shot?

Scientists are still studying this and will determine this once the vaccine is distributed and more data becomes available.

Do the new vaccine trial results mean the end to the pandemic?

The answer to this important question is unknown. The availability of a vaccine is an important step in our ability to protect vulnerable individuals and to significantly impact this disease.

Getting the COVID-19 Vaccine

Will getting the flu vaccine protect me from COVID-19?

No. However, it can protect you from getting the flu.

Should I get the vaccine if I am pregnant or currently breastfeeding?

Review of the data indicates that pregnant women are potentially at increased risk for severe COVID-19-associated illness. However, there is no data available at this time on the safety and effectiveness of COVID-19 vaccines in this population. Further considerations around use of COVID-19 vaccines in pregnant or breastfeeding individuals will be provided once data from phase III clinical trials and conditions of FDA Emergency Use Authorization are reviewed. Contact your healthcare provider with further questions.

Do I have to wait to receive the COVID-19 vaccine if I had COVID and received convalescent plasma or monoclonal antibody infusions?

Patients who were treated with monoclonal antibodies or convalescent plasma should wait at least 90 days before being vaccinated. These treatments may make the vaccines less effective.

I have a health condition that prevents me from getting vaccines with live viruses. Do you know if the COVID-19 vaccine uses a live virus?

Both Pfizer and Moderna’s vaccines are mRNA vaccines, and AstraZeneca’s and Johnson & Johnson’s are non-replicating vectored vaccines. None of the early vaccines being tested are live weakened versions of the virus. When vaccines are granted EUA and eventually licensed, part of the information that will be provided will include who should or should not get each vaccine. At this time, this information is not known.

If I have had COVID-19 should I get the vaccine?

Yes, while individuals who have tested positive for COVID-19 do produce antibodies, the antibody levels and how long they last are unknown. The ACIP, CDC and FDA will provide clarification around the role of COVID-19 vaccination in those previously infected. Individuals with documented acute SARS-CoV-2 infection in the preceding 90 days may choose to delay vaccination until near the end of the 90 day period in order to facilitate vaccination of those individuals who remain susceptible to infection, as current evidence suggests reinfection is uncommon during this period after initial infection. Of note, previous SARS-CoV-2 infection, whether symptomatic or asymptomatic, is not considered a contraindication to vaccination and serologic testing for SARS-CoV-2 antibodies is not recommended prior to vaccination.

Will people who have gotten sick with COVID-19 still benefit from getting vaccinated?

It is likely that there will be some benefit to those previously infected individuals. At this time, experts do not know how long someone is protected from getting sick again after recovering from COVID-19. The immunity someone gains from having an infection, called natural immunity, varies from person to person, and the evidence suggests natural immunity may not last very long in some people.

Will COVID-19 vaccines cause me to test positive on COVID-19 viral tests?

No. These vaccines will not cause you to test positive on viral tests, which are used to see if you have a current infection. If your body develops an immune response, which is the goal of vaccination, there is a possibility to test positive on certain antibody tests. These tests indicate you had a previous infection or vaccination and that you may have some level of protection against the virus.

Side effects

What are the side effects?

In general, the side effects experienced with the Pfizer and Moderna vaccines are relatively rare and considered mild to moderate. Much of what has been reported in early studies is consistent with other vaccines. For instance, vaccine injections may cause mild flu-like side effects — including soreness at the injection site, headaches, muscle aches and fever. It is recommended that you take ibuprofen or acetaminophen to help alleviate any such side effects following vaccination, but not before, as they may make the vaccine less effective. It should be noted that study participants did not take pain relievers before their vaccines.

What if I am concerned about my side effects?

Please seek medical attention immediately by calling your doctor’s office or setting up a virtual visit if you experience severe side effects.

Will you check my antibodies at some point after I get the vaccine?

Currently, there does not appear to be a need for this though we are prepared to do so if the guidance for the vaccine includes subsequent antibody testing. We will abide by this guidance once it is clarified.

Do I have to continue wearing a mask after I get the vaccine?

Yes. We should all continue wearing face masks, practicing excellent hand hygiene and social distancing until enough vaccines are manufactured and distributed to the general population.

Second dose

How many doses of a COVID-19 vaccine will I need?

Both the Pfizer and Moderna vaccines require an initial vaccine and a booster. The Pfizer vaccine requires a booster 21 days later and the Moderna vaccine requires a second dose 28 days later. The different vaccine products are not interchangeable. The second dose must be completed with the same vaccine brand as the first dose. Both doses are important to ensure full protection.

I tested positive for COVID-19 before I received my second dose. Can I still receive my second dose?

The CDC states that once you are no longer symptomatic and outside of your required quarantine, you can get your second vaccine.

What if I miss my second dose?

It is important that you receive your second dose. These two COVID-19 vaccines are not completely effective unless you receive the second dose. Your second dose will be scheduled at the time you receive your initial dose.

What should I expect from the second dose?

The goal of the first vaccine is to “prime” the immune response; the second “boosts” it. This is why most people experience a stronger immune response and more side effects after receiving the second dose. 

Can the second dose be given sooner or later than 21 or 28 days?

You should try to get the second dose of the vaccine as close to the recommended timeframe as possible. There is a 4-day grace period for getting the second dose early if it is necessary. On January 21, 2021, the CDC updated its guidance on the interval between vaccine doses, providing additional information on delayed dosing. Specifically, the agency says that when the recommended schedule is not feasible, the second dose may be scheduled up to 6 weeks (42 days) after the first dose. Although there is currently limited data on the efficacy of mRNA COVID-19 vaccines administered beyond this window, if the second is given later than this, the series still does not need to be restarted.