Vaccination is your best defense against serious illness from COVID-19. According to the CDC, COVID 19-vaccines are effective. Getting vaccinated yourself may also protect people around you, particularly people at increased risk for severe illness from COVID-19. By getting the vaccine, you're helping to protect yourself, your loved ones and your community.
How COVID-19 Vaccines Work
Vaccines are designed to activate the human body’s immune response to fight an infection. If you become infected with COVID-19 and you’re fully vaccinated, your immune system will recognize the infection and work to fight it.
Both currently available mRNA vaccines by Pfizer and Moderna require two doses for most people. You’ll get an initial vaccination, then a second shot — 3-8 weeks later for the Pfizer vaccine or 4-8 weeks later for the Moderna vaccine. The second dose stimulates a greater immune response, generating far more protection from COVID-19.
Boosters are recommended for most people after certain amounts of time. Find out when to schedule boosters for different age groups. You can also talk to your family doctor if you have questions about vaccinations.
According to the CDC, the Pfizer and Moderna mRNA vaccines are safe and effective. COVID-19 vaccines are not experimental. They went through all the required stages of clinical trials, including extensive testing and monitoring. The Novavax protein-based vaccine has been determined to be similarly safe and effective to the mRNA-based vaccines.
Common Vaccine Myths
- “The vaccine will give you COVID-19.” None of the authorized COVID-19 vaccines contain the live virus. This means that it’s not possible to get COVID-19 from any of the vaccines.
- “The COVID-19 vaccine will alter my DNA.” COVID-19 vaccines don’t change or interact with your DNA in any way. Both mRNA and viral vector COVID-19 vaccines deliver instructions to our cells to start building protection against the virus that causes COVID-19. All COVID-19 vaccines work with the body’s natural defenses to safely develop immunity to disease.
- “I don’t need the vaccine after I get COVID-19. The antibodies will protect me!” Even after infection, the CDC recommends getting a COVID-19 vaccine. Studies have shown that vaccination provides a strong boost in protection in people who have recovered from COVID-19. After recovery, reinfection is still possible.
- “I just got the vaccine, so it’s impossible for me to spread the virus.” Getting the COVID-19 vaccines doesn’t fully eliminate the risk of spreading the virus to others, especially with the spread of new variants and varying infection rates. To protect yourself and others, the CDC recommends practicing tried-and-tested safety measures like wearing face masks, staying six feet away from others, avoiding crowds and poorly ventilated spaces, and staying updated on your vaccines and booster shots. COVID-19 vaccines, including boosters, are still your best option to help protect against serious illness, hospitalization, and even death. The CDC recommends all people approved for a COVID-19 vaccine stay current with their primary and booster doses.
Allergies and the Vaccines
If you had a severe allergic reaction after the first dose of an mRNA COVID-19 vaccine, the CDC recommends against a second dose. If you’re considering a second dose, get evaluated by an allergist first. Please see the Pfizer and Moderna fact sheets for ingredient lists and more information.
For those taking the Janssen/J&J vaccine, a second dose is not recommended if you had a severe allergic reaction to any ingredient in the vaccine. Please see the Janssen/J&J fact sheet for an ingredient list and more information.
Getting Vaccinated After COVID-19 Infection
In most cases, you can receive the COVID-19 vaccine after you're out of isolation and your symptoms are getting better. In most cases, you can stop isolating when all of the following are met:
- 10 days have passed since the symptoms began.
- You haven’t had a fever for at least 24 hours without using Tylenol or other fever-reducing medications.
- Other symptoms have improved.
If you’re immunocompromised, please check with your doctor about how long isolation should last and when it’s safe for you to get the COVID-19 vaccine.
If you were treated for COVID-19 with monoclonal antibodies or convalescent plasma, you should wait 90 days before getting a COVID-19 vaccine. Talk to your provider if you’re unsure what treatments you received or if you have more questions about getting a COVID-19 vaccine.
Pregnancy and the COVID-19 Vaccine
Based on CDPH and CDC guidelines, pregnancy is considered a high-risk condition with an increased chance of complications from COVID-19. According to the CDC, there’s currently no evidence that COVID-19 vaccination causes any problems with pregnancy, including the development of the placenta. In addition, there’s no evidence that fertility problems are a side effect of any vaccine, including the COVID-19 vaccines. Discuss the risks of COVID-19 and taking the COVID-19 vaccines during pregnancy with your healthcare provider. Learn more about pregnancy and delivery at Sutter during COVID-19.
The COVID-19 pandemic is ongoing, so it’s best to talk to your primary healthcare provider about new COVID-19 variants, booster shots, and things you can do to help protect yourself and your loved ones.
mRNA Vaccines for COVID-19: How They Work
Vanessa Walker, D.O., explains what mRNA vaccines are and how they help your body fight COVID-19 viruses. She also addresses whether these vaccinations can lead to positive tests.
mRNA Vaccines for COVID-19: Who Should Get It
Stephanie Brown, M.D., discusses whether pregnant, breastfeeding and immunocompromised people should get the COVID-19 vaccine.
mRNA Vaccines for COVID-19: Development and Side Effects
Learn about the development and efficacy of the mRNA COVID-19 vaccines from Ganesh Krishna, M.D. Dr. Krishna also addresses side effects.