COVID-19 Vaccine: What Yous Demand to Know

Featured Experts:

  • Dr. Gabor Kelen

  • Dr. Maragakis

Updated on March vii, 2022

The U.S. Food and Drug Administration (FDA) has canonical utilize of vaccines for the coronavirus that causes COVID-19. Lisa Maragakis, 1000.D., Grand.P.H., senior managing director of infection prevention, and Gabor Kelen, M.D., director of Johns Hopkins Function of Disquisitional Outcome Preparedness and Response, accost common questions and explain how a vaccine could impact the current pandemic.

Learn more than about:

  • COVID-19 Vaccines and How They Piece of work
  • Getting the Vaccine
  • Protection and Immunity
  • Vaccine Safety and Side Effects
  • Women and Children

COVID-19 Vaccines and How They Work

How do vaccines work?

Vaccines aid people develop immunity to a virus or other germ. A vaccine introduces a less harmful part of that germ — or something created to look or behave like it — into a person's torso. The body'due south immune organization develops antibodies that fight that item germ and go along the person from getting ill from information technology. Later, if the person encounters that germ over again, their immune system can "recognize" information technology and "remember" how to fight information technology off.

Is there a vaccine for the coronavirus disease?

Yes. 2 COVID-nineteen vaccines – Pfizer and Moderna - have been fully approved by the FDA and recommended by the CDC.

Johns Hopkins Medicine views the FDA-approved mRNA vaccines from Pfizer and Moderna as highly constructive at preventing serious disease, hospitalization, and expiry from COVID-19.

The CDC notes that in most situations the ii mRNA vaccines from Pfizer and Moderna are preferred over the Johnson & Johnson vaccine due to a take a chance of serious adverse events. The J&J vaccine may be available for those who all the same adopt it and for use in sure circumstances.

It is also important to receive a booster when you lot are eligible. You tin go whatever of these three authorized or approved vaccines, but the CDC explains that Pfizer and Moderna are preferred in most situations.

Learn more than about coronavirus vaccine prophylactic.

How will a vaccine prevent COVID-xix?

The coronavirus that causes COVID-19 has spikes of protein on each viral particle. These spikes help the viruses attach to cells and cause disease. Some of the coronavirus vaccines are designed to help the body "recognize" these spike proteins and fight the coronavirus that has them.

An constructive vaccine helps protect the person who receives it from serious affliction, hospitalization and expiry. Widespread vaccination will help limit spread through communities and will restrict the virus's opportunity to go on to mutate into new variants.

When tin I get the coronavirus vaccine?

Vaccines and boosters are being distributed across the United States.

If you are a Johns Hopkins Medicine patient, visit our COVID-xix Vaccine Information and Updates page for current data on getting vaccinated or receiving a booster. Your state'southward wellness department website can also provide updates on vaccine distribution in your expanse.

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Getting the Vaccine

How many shots are in the COVID-19 vaccine?

Pfizer's and Moderna's vaccines require 2 doses given several weeks autonomously (Pfizer's second shot is given three weeks subsequently the first, and Moderna'due south is four weeks after the start).The COVID-19 vaccine from Johnson & Johnson requires only one dose.

What does "fully vaccinated" hateful?

According to CDC guidelines, you lot are fully vaccinated when it has been:

  • Two weeks subsequently your second dose in a two-dose serial, such as the Pfizer or Moderna vaccines.
  • Two weeks afterwards a unmarried dose of the Johnson & Johnson vaccine. However, data from clinical trials are clear that there is farther improvement four weeks afterwards the single-shot vaccine, especially for preventing severe COVID-19 or having asymptomatic infection. For this reason, Johns Hopkins Medicine recommends four weeks later on the unmarried-dose vaccine to be considered fully vaccinated.

If y'all don't run into these requirements, y'all are not fully vaccinated.

For the 2-dose COVID-19 vaccines, what happens if my second dose is delayed?

If yous accept received the first dose of the Pfizer/BioNTech COVID-19 vaccination, the Centers for Affliction Control and Prevention (CDC) states that the 2nd shot should have place three weeks afterward the kickoff i.

If your first coronavirus vaccine was from Moderna, the CDC says your second shot should be given to you lot 4 weeks after the offset i.

If something happens that prevents y'all from getting the second dose of either COVID-19 vaccine on time, yous tin still receive it upwardly to six weeks (42 days) after the kickoff dose. We do non recommend delaying your 2nd dose, but the data from clinical trials support this range. In that location are currently limited data on the efficacy of mRNA COVID-nineteen vaccines administered beyond this window. According to the CDC, even so, if the second dose is administered beyond these intervals, there is no need to restart the serial.

What if I received my 2d vaccination earlier than recommended?

Yous should not get the second vaccine dose earlier than the recommended times. But, if you've already received your second shot, and information technology was early by 4 days, or less than the recommended fourth dimension window, your vaccinations are OK, and you lot do not need to repeat the vaccination series.

Should I get a COVID-19 vaccine if I already had COVID-19?

Yes, evidence continues to indicate that getting a COVID-xix vaccine is the best protection against getting COVID-19, whether yous have already had COVID-19 or not.

  • A study published in August 2021 indicates that if you had COVID-xix earlier and are not vaccinated, your take chances of getting reinfected is more than two times college than for those who were infected and got vaccinated.
  • While testify suggests at that place is some level of amnesty for those who previously had COVID, information technology is not known how long you are protected from getting COVID-19 again. Plus, the level of immunity provided by the vaccines after having COVID-19 is higher than the level of immunity for those who had COVID merely were not subsequently vaccinated.
  • Getting vaccinated provides greater protection to others since the vaccine helps reduce the spread of COVID-xix.

At the time of vaccination, exist sure to tell your care provider about your history of COVID-xix affliction, including the kind of handling, if whatsoever, you lot received and when y'all recovered. Wait until your isolation menstruation ends before making an appointment to get the vaccination.

Protection and Immunity

If I get a coronavirus vaccination, practise I all the same have to wear a mask? Concrete altitude?

The CDC continues to monitor the spread of COVID-19 and makes recommendations for wearing face masks, both for those who are fully vaccinated as well as those who are not fully vaccinated.

The CDC likewise recommends that masks and concrete distancing are required when going to the doctor's office, hospitals or long-term care facilities, including all Johns Hopkins hospitals, care centers and offices.

Johns Hopkins Medicine'south current mask rubber guidelines take not changed, and nosotros nonetheless crave all individuals to article of clothing masks inside all of our facilities.

Does taking over-the-counter medications before receiving the vaccine lessen its effectiveness?

Some studies have suggested that taking medications such as Tylenol or Advil before getting a vaccination might reduce your trunk'southward power to mount an immune response to the vaccine. It'southward unclear if these findings take any clinical significance, though, and other studies did not observe any outcome of anti-inflammatory medications on the immune reaction to vaccines.

If you lot regularly accept aspirin or other over-the-counter medications such equally acetaminophen (e.g., Tylenol), ibuprofen (eastward.thou., Motrin, Advil) or naproxen (e.g., Aleve) for other medical atmospheric condition, delight continue to do so as directed by your physician or every bit needed. Otherwise, it'south probably best to not have over-the-counter medications such as acetaminophen or ibuprofen that reduce fever or inflammation before receiving a vaccine. If yous are uncomfortable or take symptoms subsequently vaccination, that is the time to have an over-the-counter medication to help you feel improve.

Vaccine Prophylactic and Side Effects

How will we know if a COVID-19 vaccine is safe and effective?

In society to be declared safe and effective, a COVID-xix vaccine must laissez passer certain tests and standards. Organizations such as the National University of Sciences, the National Institutes for Health, and the Nutrient and Drug Assistants (FDA) utilise scientific data from research to help decide if and when new drugs and vaccines can go available to the public. It is important to notation that you cannot get COVID-nineteen from a vaccine. The vaccines contain proteins or other biological substances to stimulate the immune response, just not the coronavirus itself.

Larn more about the safety of the COVID-nineteen vaccines.

Demographics of the COVID-19 Vaccine Trials

What are the coronavirus vaccine side effects?

You may have pain in the arm where y'all got the shot, and you might run a fever and feel trunk aches, headaches and tiredness for a twenty-four hours or two. Chills, bloated lymph nodes can also occur.

Read more near possible COVID-19 vaccine side effects.

Is it OK to get the COVID-nineteen vaccine if I have allergies?

While there have been reports of severe allergic-type reactions in a very pocket-sized number of patients, the CDC says that people with allergies to certain foods, drugs, insects, latex and other common allergens can still get the COVID-19 vaccine.

If you have had a severe allergic reaction (anaphylaxis) to injectables or other vaccines, be sure to hash out the COVID-xix vaccination with your doctor, who tin evaluate y'all and assess your risk. The vaccine provider should detect you for xxx minutes rather than the routine fifteen minutes after vaccination, and if yous accept an allergic reaction to the starting time shot, y'all may not receive the 2d.

The CDC says that at this time, anyone who has a severe allergy (such as anaphylaxis) to whatsoever of the vaccine ingredientsshould not get that vaccine.

How Practice Nosotros Know a COVID-nineteen Vaccine Will Be Safe and Effective?

Women and Children

Can children receive a COVID-xix vaccine?

The Centers for Illness Control and Prevention (CDC) now recommends a COVID-xix vaccine for children ages v and older. Johns Hopkins Medicine encourages all families to have eligible children vaccinated with the COVID-19 vaccine. Currently, Pfizer's vaccine is the merely approved COVID-19 vaccine for children and teens historic period 5 to 17.

Read more about what parents need to know about the COVID-xix vaccine.

Does the COVID-19 vaccine interfere with getting a mammogram?

Getting a mammogram too presently after your 2nd dose of the coronavirus vaccine could result in a false positive and a callback due to temporarily swollen lymph nodes.

The Johns Hopkins Sectionalisation of Breast Imaging supports the recommendation from the Gild of Breast Imaging: When possible, and if it does not delay care your md recommends, you should schedule screening mammograms before your outset dose of a COVID-nineteen vaccine or 4 to six weeks after the 2nd dose.

Read more about the COVID-nineteen vaccine and mammograms.

Why is it Important that I Consider Getting the COVID-nineteen Vaccine?