How do vaccines work?
Vaccines trigger the body’s natural response to fight illnesses. Vaccines work by training the immune system to be ready to recognize viruses or bacteria when they enter the body. Then, if a person is exposed to that virus or bacteria, their immune system knows how to respond. The COVID-19 vaccines protect people from getting seriously ill and requiring hospitalization. If a vaccinated person gets COVID-19, they usually have mild symptoms.
Are COVID-19 vaccines safe?
Yes. The United States Food and Drug Administration (FDA) works to make sure that all vaccines are as safe and effective as possible through careful testing. All vaccines must meet strict safety standards before being released to the public. Approval is only given if the vaccine is shown to be safe and the reviewers conclude that the benefits outweigh any potential risks. Over 600 million people of different ages and races have received COVID-19 vaccines and boosters. These vaccines are safe and are regularly monitored by the FDA and U.S. Centers for Disease Control and Prevention (CDC).
What are in the COVID-19 vaccines?
The Moderna and Pfizer vaccines have mRNA, genetic material that our cells use to make spike proteins. Then our bodies respond by making antibodies. The mRNA COVID-19 vaccines do not have preservatives, which is why they must stay frozen until they are ready to use. Novavax is a protein-based vaccine. Novavax stimulates an immune response using a technique that is well-known and established. It is similar to other common vaccines you may have had such as seasonal flu, pertussis, and hepatitis B. Vaccines may also have lipids, salts, sugars, acids, and acid stabilizers to help keep them stable to deliver the active ingredients. Vaccines do not contain ingredients that are poisonous or harmful.
Updated Pfizer-BioNTech, Moderna, and Novovax COVID-19 vaccines were approved in the fall of 2024 in the United States. These 2024-2025 vaccines are expected to offer better protection against serious illness from the current variants (changes in the virus).
Who can get a COVID-19 vaccine?
The CDC recommends 2024-2025 COVID-19 vaccines for everyone aged 6 months and older.
What COVID-19 vaccines are available?
• The FDA has given approval for the Pfizer and Moderna vaccines for people 6 months and older.
• The FDA has given approval for the Novavax COVID-19 vaccine for people 12 years and older. Novavax offers an alternative to the mRNA vaccines for people who cannot or prefer not to get an mRNA vaccine. Check with your health care provider for an updated dose schedule.
• The Johnson & Johnson (J&J/Janssen) COVID-19 vaccine is no longer avaialble in the United States.
Are the COVID-19 vaccines effective?
Yes. The vaccines produce a strong immune response in adults and young children and protect against severe disease. While certain virus variants that cause COVID-19 spread easily and may lead to breakthrough cases, vaccines continue to protect people from becoming very sick, being hospitalized, or dying from COVID-19. Even with new variants, getting vaccinated is a safe and reliable way to protect yourself from COVID-19. Scientists will continue to monitor these variants.
When are people considered “up-to-date” on their COVID-19 vaccines?
Consult with a health care provider about your/your child’s vaccine status, and check the most up-to-date CDC guidance. In the fall of 2024, the CDC recommends:
- Everyone aged 5 years and older get 1 dose of the 2024-2025 Pfizer-BioNTech or Moderna COVID-19 vaccine
- Check with your health care provider for children 6 months to 4 years of age since the number of doses may be different depending on their age and type of vaccine, Pfizer-BioNTech or Moderna COVID-19 vaccine
- Check with your health care provider if you are a person who is moderately or severely immunocompromised. You may need additional COVID-19 vaccines.
- See the complete schedule at the California Department of Public Health (CDPH), Immunization Branch https://eziz.org/assets/docs/COVID19/IMM-1396.pdf
COVID-19 vaccine recommendations will be updated as needed. Vaccine may be available in the future to protect against different variants.
How long do COVID-19 vaccines protect people?
The COVID-19 vaccines offer the best protection against getting sick with COVID-19 in the months following the shot. Two weeks after getting the vaccine, the risk of getting sick is low, and the risk gradually goes up over the first six months. However, the vaccine provides protection against severe disease, hospitalization, and death.
Are there side effects?
There can be side effects. The most common side effect is pain in the arm where people get the vaccine. Some people also have one or more of these symptoms: tiredness, headache, muscle pain, chills, joint pain, and fever. Another side effect is swollen lymph nodes in the neck or under the arm where the vaccine was given. These are all signs of the body’s immune system working.
These side effects usually clear up within a day or two. Keep in mind, the side effects from the vaccine are generally much milder than getting COVID-19. A very small number of the many people vaccinated have had more serious side effects such as a severe allergic reaction but this is rare. Talk to your health care provider if you or your child have had a severe allergic reaction to other vaccines or ingredients.
Should people who have already had COVID-19 get the vaccine?
Yes, you should get a COVID-19 vaccine even if you already had COVID-19.
- People who have had COVID-19 may have some immunity, but this immunity can vary depending on how mild or severe the illness was and their age. The immunity also decreases over time. There is no current test to tell if a person is protected.
- Getting the vaccine is a safer way to build immunity against COVID-19 and its variants than getting sick with the COVID-19 virus.
- The vaccine will help your body have a stronger response if you get COVID-19 again.
- People with COVID-19 should wait until they are no longer infected, and check with their health care provider before getting the vaccine.
Do people still need to wear a mask after they've had the vaccine?
Wearing a mask is an additional way to protect yourself and others. This is especially important if:
- you test positive for COVID-19
- you were exposed to COVID-19 and will be in close contact with someone at high risk for severe disease
- you are at risk for severe disease or are immunocompromised
- your child care program is experiencing a COVID-19 outbreak
Follow California Department of Health guidelines if you test positive for COVID-19, you are exposed, or you have symptoms.
Where can people get COVID-19 vaccines?
This will vary by county. You can get a vaccine from local pharmacies like CVS or Walgreens, from your health care provider, or from your public health clinic. Your local health department or school district may also be holding vaccination clinics. Check with your local public health department or primary care provider about where the vaccine is available in your location. Parents or legal guardians need to provide signed consent for their child to receive the vaccine. For access to vaccines, visit the CDPH COVID vaccines website.
What does the vaccine cost?
Most health care plans a provide the vaccine free of charge. Individuals without coverage may use the Vaccines for Children program to receive free vaccines.
How do I talk to my child about getting the COVID-19 vaccine?
It’s important for children to understand that the vaccine is meant to keep them healthy and safe.
- Be honest that the shot may hurt a bit and that the child might feel tired after they get the shot.
- Explain that getting the shot will protect others as well.
- Allow children to express their concerns and ask questions.
- On the day your child gets vaccinated, bring a comfort object, such as a favorite toy.
If COVID-19 is less severe in children than adults, why should my child get vaccinated?
Even though children experience less severe COVID-19 than adults, vaccination will protect your child in the following ways:
- They are less likely to get sick with COVID-19. Not getting sick is even more important for children with underlying health conditions.
- They are less likely to get severe illness, be hospitalized, get multisystem inflammatory syndrome (MIS-C), or die if they get COVID-19.
- They are less likely to miss school because of being infected with COVID-19.
- They are less likely to spread COVID-19 to more vulnerable family, friends, teachers, and classmates.
- Your family will be able to travel more freely with less worry about getting COVID-19.
- It will be safer for your child to attend important educational, cultural, and social activities and family events.
- Getting vaccinated can help stop new variants from emerging
Will my child be required to get the vaccine for child care entry?
Each state's government decides which vaccines are required for school or child care entry. At this time, there is no state-wide California requirement for COVID-19 vaccination for child care entry.
Is the vaccine required for child care workers?
Not always. Some employers require vaccination for their workers. Getting vaccinated helps protect you and the children under your care.
Is the vaccine recommended for pregnant women?
Yes. The COVID-19 vaccination is recommended for pregnant women. The CDC recommends that all people who are pregnant, breastfeeding, trying to get pregnant, or might become pregnant in the future be vaccinated for COVID-19.
Pregnant women are more likely to get severely ill if they get COVID-19, compared with non-pregnant women. Women who contract COVID-19 while pregnant also face a higher risk of having a preterm birth. Getting a COVID-19 vaccine during pregnancy can also help protect the baby from COVID-19. Pregnant people should talk to their health care providers about getting the vaccine.
Where can I find more information?
Contact your medical provider if you have any questions about vaccines.
Centers for Disease Control and Prevention (2024) Staying Up to Date with COVID-19 Vaccines at https://www.cdc.gov/covid/vaccines/stay-up-to-date.html
Centers for Disease Control and Prevention (2024) COVID-19 Vaccine Basics at https://www.cdc.gov/covid/vaccines/how-they-work.html
California Department of Public Health (2024) COVID-19 Vaccines at https://www.cdph.ca.gov/Programs/CID/DCDC/Pages/COVID-19/Covid19Vaccines.aspx
Updated December 2024, UCSF California Childcare Health Program
This article was made possible with funding from the Heising-Simons Foundation.
