COVID-19 Vaccine Safety

Are the COVID-19 vaccines safe?

Munson Healthcare takes the safety of any vaccine very seriously. We review the safety evidence for any potential vaccine as well as recommendations from the Food and Drug Administration, the Advisory Committee for Immunization Practices (APIC), and the CDC before offering any vaccine.

We understand that some people may be concerned about the COVID-19 vaccine. These  vaccines were evaluated in tens of thousands of participants in clinical trials and met the rigorous scientific standards for safety, effectiveness, and manufacturing quality needed to support emergency use authorization. Millions of people in the United States have now received COVID-19 vaccines under the most intense safety monitoring in U.S. history. 

While these vaccines were developed as quickly as possible through the help of global cooperation and unprecedented public and private funding, routine processes and procedures remain in place to ensure the safety of any vaccine that is authorized or approved for use. Safety is a top priority. The U.S. vaccine safety system ensures that all vaccines are as safe as possible.

For more information about the safety of the vaccine, visit

What is the process for approving a COVID-19 vaccine and ensuring it is safe?

According to the CDC, “the federal government has been working since the start of the pandemic to make a COVID-19 vaccine available as soon as possible. This accelerated timeline is unprecedented and has raised concerns for some people that safety may be sacrificed in favor of speed. However, as with all vaccines, safety is a top priority.

COVID-19 vaccines were tested in large, three-phase clinical trials to make sure they meet safety standards. Many people were recruited to participate in these trials to see how the vaccines offer protection to people of different ages, races, and ethnicities, as well as those with different medical conditions.”

How can a safe vaccine be available so quickly?

It normally takes years to develop a vaccine. However, due to previous outbreaks caused by related coronaviruses such as SARS (Severe Acute Respiratory Syndrome) and MERS (Middle East Respiratory Syndrome), vaccine research had already begun. This provided a head start for the rapid development of vaccines to protect against COVID-19. 

Additional steps were also taken to shorten the timeline without sacrificing safety:

  • Overlapping phase I and phase II clinical trials. Phase I studies include a small number of people and evaluate whether the vaccine causes an immune response and is safe. Scientists could evaluate data from phase I individuals as phase II was progressing to make these evaluations.
  • While completing large phase III trials, manufacturers began producing the vaccine. so they would have large numbers of doses ready if it was shown to be safe and effective. This is not normally done because if the vaccine does not work, the manufacturer would have invested significant resources to produce something that needs to be thrown away.
  • Traditional vaccine production involves growing viruses in living cells and purifying the virus. There are challenges associated with this process that takes time. The mRNA vaccine has an advantage in that large amounts of the mRNA can be synthesized very rapidly.
  • While waiting for a vaccine to be ready, many other aspects of vaccine delivery were prepared (e.g., developing plans for how to distribute the first, limited quantities available, and ensuring adequate supplies for distributing and administering vaccine).

What is Emergency Use Authorization (EUA)?

In certain types of emergencies, the U.S. Food and Drug Administration can issue an emergency use authorization, or EUA, to provide more timely access to critical medical products (including medicines and tests) that may help during the emergency when there are no adequate, approved, and available alternative options.

The EUA process is different than FDA approval, clearance, or licensing because the EUA standard may permit authorization based on less data than would be required for approval, clearance, or licensing by the FDA. This enables the FDA to authorize the emergency use of medical products that meet the criteria within weeks rather than months to years. 

EUAs are in effect until the emergency declaration ends but can be revised or revoked as we evaluate the needs during the emergency and new data on the product’s safety and effectiveness, or as products meet the criteria to become approved, cleared, or licensed by the FDA.

After the clinical trials are complete:

  • The Food and Drug Administration (FDA) carefully reviews all safety data from clinical trials and authorizes emergency vaccine use only when the expected benefits outweigh potential risks.
  • The Advisory Committee on Immunization Practices (ACIP) reviews all safety data before recommending any COVID-19 vaccine for use. Learn how ACIP makes vaccine recommendations.
  • FDA and CDC will continue to monitor the safety of COVID-19 vaccines, to make sure even very rare side effects are identified.

To-date, current vaccines appear to be effective against variants but we cannot predict if that will remain true if the virus continues to mutate into additional variants.

Why were children under 16 not included in the initial clinical trials?

On May 10, the FDA authorized the Pfizer-BioNTech COVID-19 Vaccine for emergency use in adolescents 12 and older. The U.S. Food and Drug Administration (FDA) and the CDC's Advisory Committee on Immunization Practices (ACIP) have both supported the emergency use authorization (EUA) of Pfizer's COVID-19 vaccine for kids ages 12 and older. The authorization follows extensive research from the CDC, determining Pfizer's COVID-19 vaccine to be both safe and effective for kids age 12 and up.

Children are not routinely included in initial drug and vaccine trials. Children are still growing and developing. For example, there are big differences between the maturity of immune systems in 2-year-olds versus 12-year-olds. For this and other reasons, trials with children must be separated by several age groups, which means many more participants were needed.

What are the potential side effects of the vaccine?

Most recipients do not report serious problems after being vaccinated. Some studies have begun to show that COVID-19 vaccines may cause a stronger immune response than other vaccines you are familiar with. Common COVID-19 vaccine symptoms include:

  • A sore, red, or warm arm (goes away within a week or less)
  • Low-grade fever
  • Headache 
  • A general “I’m not quite my normal self” feeling
  • Nausea

These are normal signs that your immune system is doing exactly what it is supposed to - produce an immune response so you have protection against the disease.

For two-dose vaccines:

Some symptoms listed above may feel more significant after a second dose. Increased fatigue in the hours following a second dose has also been reported. However, there is no marked increase in vaccine recipients reporting severe adverse reactions following a second dose.

Please make sure to schedule and receive your second dose unless a vaccine provider or your doctor advises otherwise.

Click here for specific information on authorized and released COVID-19 vaccines in the United States.

Are there any long-term side effects of the COVID-19 vaccine?

The standard length of time for clinical trials to observe long-term effects in vaccines is six weeks. Any long-term effects that may be present are likely to be found within this timeframe. The COVID-19 clinical trials observed participants for at least two months to ensure long-term effects could be evaluated. No significant long-term side-effects were reported or observed. Those studies are ongoing and as more people are vaccinated, we will get more information about both short term and long term safety and efficacy.

Is the vaccine safe for pregnant women or mothers who are breastfeeding?

Current guidance is that pregnant and breastfeeding women should work with their doctor to judge the risks and benefits of receiving the vaccine. 

The American College of Obstetricians and Gynecologists (ACOG) along with the Society for Maternal-Fetal Medicine (SMFM) recently published a joint statement supporting COVID-19 vaccines for people who are pregnant, nursing, or who may become pregnant. The joint statement notes that although there is no long-term data on the use of vaccines in pregnancy, it is anticipated that they are likely to be very safe and should be offered to all individuals who would otherwise be candidates for the vaccine.

Pregnant women, like children, are routinely excluded from initial vaccine trials, which means there is little reported data on vaccines during pregnancy. Ninety percent of all FDA-approved drugs have not been tested in pregnant women for a few reasons:

  • Given less than five percent of the population is pregnant at any given time, and that pregnancy may not span the length of the trial, it is very difficult to recruit a large enough population of pregnant women to produce significant results that demonstrate effect.
  • Most pregnant women choose not to participate in trials for drugs and vaccines.

It may be helpful to talk to your healthcare provider as you make this decision.

Will vaccinated Munson Healthcare staff continue following safety protocols, such as wearing proper Personal Protection Equipment (PPE)?

Yes, Healthcare Team members will continue to wear PPE, even after being vaccinated, because it is just one of the many tools we have to combat the virus. The vaccine, along with PPE, handwashing, and social distancing helps stop the spread of COVID-19. Learn more about how we’re keeping you safe.