Answers to common COVID-19 vaccine questions

By The Health News Team | May 4, 2021
Woman asks question between vaccine and virus sick risk.

Vaccination clinics across San Diego are abuzz with locals getting their first, second — even their third — dose of a COVID-19 vaccine. You can hear the hum of excitement — and you may even witness a few tears of relief and joy — as shots in arms offer a glimmer of hope for a better tomorrow.

While the number of people vaccinated in the county increases each day, we are still seeing a rise in COVID-19 cases. Experts advise that more people need to get vaccinated to effectively slow the spread of the coronavirus that causes COVID-19.

Whether they simply have not yet had the opportunity to schedule an appointment, have a wait-and-see attitude or have concerns about vaccination, the hope is that they will soon join their neighbors in receiving a COVID-19 vaccine to help San Diego achieve a safe and full reopening of the economy and schools, and a return to the activities we all enjoy. Here are answers to some of the common COVID-19 vaccine questions people might have.

Top COVID-19 vaccine questions answered

Why should I get vaccinated?
COVID-19 can have serious, life-threatening complications. The vaccine will help keep you from getting seriously ill, even if you do get COVID-19, and may also protect people around you, particularly people at increased risk for severe illness from COVID-19.

Are the vaccines safe?
Hundreds of millions of people have received COVID-19 vaccines, and serious side effects are extremely rare. While use of the Johnson & Johnson (J&J) single-dose vaccine was approved for use by the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA), both agencies recommend that the mRNA vaccines — considered highly safe and effective — should be preferred when available, due to reports of rare blood clots in approximately 1 in 100,000 women who received the J&J vaccine. This risk has not been seen in the mRNA vaccines made by Pfizer and Moderna.

How were the vaccines developed so quickly?
No steps were skipped in the development of the vaccines. Government funding allowed for multiple steps to happen at once, rather than one step needing to be completed before another step begins. So the process was quicker, but just as thorough.

Do the vaccines work?
Yes, the vaccines are effective. During trials, the vaccines currently available in the U.S. were highly effective in preventing serious disease, hospitalizations and death from COVID-19. When a booster dose is added, the vaccines are also highly effective at preventing infection. 

Could I have an allergic reaction to the vaccines?
Allergic reactions are rare. Serious allergic reactions have occurred in approximately 2 to 5 people per 1 million vaccinated in the U.S. These reactions almost always occur within 30 minutes after vaccination, and vaccine providers have medicines available to effectively and immediately treat any serious reactions.

Are there vaccine side effects?
People may experience sore muscles and mild fever, especially after the second and booster doses of the Pfizer and Moderna COVID-19 vaccines. These are not allergic reactions. Instead, these symptoms mean the body's immune system is working as it is supposed to after a vaccine. Some people plan for a day off to rest after their second and booster doses, but many experience mild symptoms or no side effects at all.

What is in the vaccines?
The Pfizer, Moderna and Janssen COVID-19 vaccine ingredients are listed online. While the ingredient names may be unfamiliar to nonscientists, it is important to know they represent some fairly basic things: salts, sugars and buffers to stabilize the vaccine and balance its pH levels, plus ingredients to protect the vaccines from contamination. The Pfizer and Moderna vaccines are mRNA vaccines, so they also include fatty lipids to surround and protect the delicate mRNA molecules.

Can the vaccines give me COVID-19?
No, there is no live virus in the vaccines, so you can't get COVID-19 from vaccination.

Can the vaccines change my DNA?
No, the vaccines do not mix with or alter your DNA. Both the Pfizer and Moderna vaccines contain messenger ribonucleic acid, or mRNA. The mRNA does not mix with or alter DNA because it never enters the cell nucleus where the DNA is located. Instead, it works within the fluid of the cells, called cytoplasm.

Do the vaccines affect fertility?
There is currently no evidence that any vaccines, including COVID-19 vaccines, cause fertility problems. If you are trying to become pregnant now or want to get pregnant in the future, you may receive a COVID-19 vaccine.

I already had COVID-19. Do I still need to get a vaccine?
Yes. Because repeat infection is possible, people who have tested positive for COVID-19 should get vaccinated once they've recovered and are no longer contagious to others.

Do I have to pay for a vaccine?
No, the vaccines are free. The federal government has paid for COVID-19 vaccines for all Americans. While your insurance plan may be billed for costs to give the vaccine to you, you will not have to pay anything.

How do I get vaccinated?
There are many ways to get a COVID-19 vaccine. San Diegans 5 and older are eligible to get the vaccine. Schedule your appointment through, on the county's website, or at one of the many pharmacies offering COVID-19 vaccines, including Albertsons/Vons, Costco, CVS, Rite Aid, Walgreens and Walmart

Learn more about COVID-19 vaccines.

This story was updated Dec. 22, 2021.

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