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COVID-19 Vaccine: Frequently Asked Questions

Click here to learn if you're eligible for the COVID-19 vaccine. 

With distribution of the COVID-19 vaccine now under way, the priority is to immunize frontline health care workers, public safety and essential workers, long-term nursing home residents and those over 65, as outlined by the NYS Department of Health. Following this initial phase, which will require several weeks, the process will move to vaccinating all Long Islanders. 

The U.S. Food & Drug Administration (FDA) granted Emergency Use Authorization (EUA) to the vaccine because in trials with tens of thousands of participants it showed itself to be extraordinarily effective, close to 95%, with little or no side effects, lasting only 24-48 hours.

“It’s important to point out that in developing a vaccine for COVID-19, researchers weren’t starting from scratch,” notes Catholic Health Services’s Executive Vice President and Chief Clinical Officer Patrick M. O’Shaughnessy, DO, MBA, MS-PopH, FACEP, CHCQM. “Past research on SARS (Severe Acute Respiratory Syndrome) and MERS (Middle East Respiratory Syndrome) had already identified potential approaches.”

Other key COVID-19 vaccine facts from the U.S. Centers of Disease Control and Prevention (CDC): 

  • The COVID-19 vaccination will help protect you from getting the SARS-CoV-2 corona virus. Two doses are needed, to be administered three to four weeks apart.
  • After receiving the COVID-19 vaccine, you may experience some side effects. This is a normal sign that your body is building protection. Side effects may feel like flu but should go away within 24-48 hours.
  • Vaccine doses purchased with U.S. taxpayer dollars will be given to the American people at no cost.
  • The first COVID-19 vaccines being used have been authorized for emergency use by the FDA. Other vaccines are being developed and tested and are expected in the months ahead.
  • COVID-19 vaccines are one of the many important tools to help stop this pandemic. The CDC continues to encourage you to cover your mouth and nose with a mask when around others, stay at least six feet away from others, avoid crowds and wash your hands often.

Frequently Asked Questions About the COVID-19 Vaccine 

Is it safe? 

The safety and efficacy of the vaccines was 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. In addition, NYS hired its own investigative staff to ensure that there were no reported serious safety concerns from these two vaccines. The CDC and the FDA will continue to monitor individuals who have received the vaccine to ensure safety. 

How effective is the new COVID-19 vaccine?

The clinical trials included more than 40,000 participants for the Pfizer vaccine and 30,000 participants for the Moderna vaccine. Each demonstrated an effective rate of more than 90% with no serious side effects. 

What are the side effects? 

Pfizer has said that some Phase III clinical trial participants experienced mild-to-moderate side effects with its investigational COVID-19 vaccine candidates. Scientists anticipate that the shots may cause mild flu-like side effects—including sore arms, muscle aches and fever for a day or two. Therefore, it is recommended that you take ibuprofen or acetaminophen (if you can safely take them) before you get the vaccine. This will help to alleviate the side effects. 

Can I get COVID-19 from the vaccine? 

It is not possible to get COVID-19 from vaccines. The Pfizer and Moderna vaccines use only one gene from the virus while other vaccines being studied use an inactivated virus. None of these can cause COVID-19. 

When will the vaccine be available for the general public? 

Following guidelines set forth by the National Academy of Medicine, the CDC and New York State Department of Health, our first priorities are frontline health care workers, public safety and essential workers and those most vulnerable to the disease like long-term nursing home residents and those over 65. After that, the vaccine will be rolled out to the general public. 

Once the priority groups are been immunized, how do I make arrangements for my vaccination? 

Once the priority groups have been immunized, all Catholic Health hospitals and many practices associated with Catholic Health will be able to accommodate your request for a COVID-19 vaccination. Your Catholic Health physician will contact you when the vaccine is available for general use.

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

Both the Pfizer and Moderna vaccines require two doses a few weeks apart. 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. 

Is the COVID-19 vaccine free?

Vaccine doses purchased with U.S. taxpayer dollars will be given to the American people at no cost. 

Are there any groups that are advised not to get the vaccine?

The vaccine is generally not recommended for children under the age of 16, women who are pregnant, or those who have a history of severe allergic reactions to medications.

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 the Pfizer and Moderna vaccines are messenger-RNA vaccines, and AstraZeneca’s and Johnson & Johnson’s are inactivated vaccines. None of these early vaccines being tested are live versions of the virus. We recommend consulting with your health care provider to determine which vaccine is best for you given your medical history. 

Can a COVID-19 vaccine be given to a person sick with COVID-19? 

We expect that will be based on the degree of the person’s illness. The Advisory Committee on Immunization Practices (ACIP) will make this clear in its “precautions and contraindications” advice regarding each of the vaccines. 

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

Yes, it recommended that even those who have had COVID-19 get the vaccination, waiting at least 10 after the end of symptoms. While individuals who have tested positive for COVID-19 do produce antibodies, the antibody levels and how long they last are yet not known. 

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 of the vaccine is manufactured and distributed, we know how long a vaccine will protect us, and until our community shows minimal levels of COVID-19 spread. 

Additional Frequently Asked Questions About Vaccines

What is a vaccine? 

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

How does the vaccine for COVID-19 work? 

Both the Pfizer and Moderna vaccines use novel messenger-RNA, or mRNA technology, which uses genetic material to cause the body to create a protein from the virus. The immune system then recognizes the protein and attacks the virus to which it is attached. This would be the first mRNA product to be approved by the FDA. The Pfizer study enrolled 43,538 volunteers. About 42% of global participants and 30% of U.S. participants have racially and ethnically diverse backgrounds. In Pfizer and BioNTech’s late-stage clinical trial, 50% of the volunteers got the vaccine, while the other half got a placebo of saltwater. An independent board of experts looked at the placebo and vaccine participants and reported that the vaccine is 95% effective.

Are there other vaccines being studied? 

Yes, the AstraZeneca and University of Oxford team, as well as Johnson & Johnson/Janssen, are also working on a vaccine but using different technology for delivering the viral genes that can produce viral proteins to activate the immune system. Novavax and the Sanofi/GlaxoSmithKline are working on a vaccine that uses proteins themselves to trigger an immune response. All are close to completing their testing. 

Will it keep me from getting COVID-19? 

Current data shows that both the Pfizer vaccine and Moderna vaccines are 95% effective in preventing the recipient from getting COVID-19. The companies will continue to test people in the studies for antibodies to the COVID-19 virus, which would include people who did not show any symptoms of their infection, so they can get a better sense of whether or not the vaccines protect against not only getting sick but also against infection. 

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

The Pfizer vaccine requires two doses. The first one is expected to be 50% effective, then the second dose, to be administered three week later, should boost your immunity past 90%. It normally takes two to three weeks for cellular immunity to develop and several weeks for a full antibody response. 

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

A flu vaccine will not protect you from getting COVID-19, but it can prevent you from getting influenza (flu) at the same time as COVID-19. This can keep you from having a more severe illness. While it’s not possible to say with certainty what will happen in the winter, the CDC believes it’s likely that flu viruses and the virus that causes COVID-19 will both spread during that time. You should encourage all of your friends and family to get flu shots. 

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 you may test positive on some antibody tests. Antibody tests indicate you had a previous infection or vaccination and that you may have some level of protection against the virus. Experts are currently looking at how COVID-19 vaccination may affect antibody testing results. 

What are the odds I’ll still catch COVID-19? 

According to the CDC, we won’t know how long immunity lasts until we have a vaccine and more data on how well it works. Both natural immunity and vaccine-induced immunity are important aspects of COVID-19 that experts are trying to learn more about. The CDC will keep the public informed as new evidence becomes available. 

Is this an annual shot? 

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

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

In the short term, no. The earliest the coronavirus vaccines could become widely available to the public would be in the spring. But if effective vaccines become available—and if most people get them —the pandemic could drastically shrink. This means we are one giant step closer to getting our lives back to normal. 

Information provided by Centers for Disease Control and Prevention 

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