Vaccine Hub

None of the COVID-19 vaccines currently in use in the United States use the live virus that causes COVID-19. The goal for each of them is to teach our immune systems how to recognize and fight the virus that causes COVID-19. Sometimes this process can cause symptoms, such as fever. These symptoms are normal and are a sign that the body is building immunity and learning how to fight the vaccine. It typically takes a few weeks for the body to build immunity after vaccination. That means it is possible a person could be infected with the virus that causes COVID-19 just before or just after vaccination and get sick. This is because the vaccine has not had enough time to provide protection.

Vaccines won’t cause you to test positive on viral tests, which are used to see if you have a current infection. If your body develops an immune response, which is the goal of vaccination, there is a possibility you may test positive on some antibody tests. Antibody tests indicate you had a previous infection and that you may have some level of protection against the virus.

Due to the severe health risks associated with COVID-19 and the fact that reinfection with COVID-19 is possible, people are advised to get a COVID-19 vaccine even if they have been sick with COVID-19 before. The immunity someone gains from having an infection, called natural immunity, varies from person to person. Evidence suggests natural immunity may not last very long.

While many people with COVID-19 have only a mild illness, others get severely ill and many have died.  COVID-19 vaccines are the best protection against severe illness from a COVID infection. Since COVID-19 variants continue to evolve, it is possible that a person who is fully vaccinated and up-to-date with their boosters may still become ill. However, these “breakthrough infections” are typically mild compared to those who are not vaccinated or up-to-date with their vaccines.

Yes, you should still get a COVID-19 vaccine even if you already had a COVID-19 infection. A vaccine will provide more protection. According to the CDC, those who do not get vaccinated following a COVID-19 infection are more likely to get COVID-19 again. Talk to your provider about when to schedule your vaccine after recovery.

Yes, you can still become infected with COVID-19 after getting a vaccine. You can become infected while your body is developing its immunity to the virus since this process takes a few weeks. Or, you can experience a breakthrough infection after being fully vaccinated. However, being vaccinated will still provide the best protection against severe illness and hospitalization from COVID-19.  

Yes, if a fully vaccinated person experiences a breakthrough infection, it is possible for them to spread the virus to others.

Click here for answers to other common vaccine questions.

If you experience COVID-19 symptoms, isolate at home and away from others until you have not had a fever for at least 24 hours without fever-reducing medicine.

If you must leave home, wear a correctly fitted mask at all times and avoid unnecessary contact with others.

It is strongly recommended that you test negative before leaving isolation. 

For more information on COVID-19 Isolation Requirements, please see:

• LA County Department of Public Health COVID-19 Isolation Instructions
• Orange County Health Agency Health Officer’s Orders & Recommendations

Quarantine requirements:

If you are a close contact to someone that tests positive or is diagnosed with COVID-19, you must do the following:

• No symptoms after exposure: no need to quarantine
  • Wear a well-fitting mask around others for 10 days
  • Test for COVID-19 within 3 to 5 days after exposure.
    • If you test positive, follow isolation instructions.
    • If you had a positive COVID-19 test in the last 30 days, you only need to test for COVID-19 after exposure if you develop symptoms.
  • Monitor your health for 10 days.
• Symptoms after exposure
  • Test for COVID-19 and follow isolation instructions

There may be additional requirements based on where you live or work. For more information on COVID-19 Quarantine Requirements, please see:

• LA County Department of Public Health COVID-19 Instructions for Close Contacts (General Public)
• Orange County Health Agency Health Officer’s Orders & Recommendations

You are a “close contact” if you shared the same indoor airspace for a total of 15 minutes over a 24-hour period with someone who tested positive for COVID-19.

If you were exposed, please following the quarantine instructions provided by your local public health department. For information on COVID-19 Quarantine Requirements, please see:

• LA County Department of Public Health COVID-19 Instructions for Close Contacts (General Public)
• Orange County Health Agency Health Officer’s Orders & Recommendations

Also see: What to Do If You Are Exposed to COVID-19

Regardless of when your isolation or quarantine ends, those with COVID-19 infection or exposure should wear medical grade masks indoors and outdoors until 10 days have passed since initial infection or last exposure.

Some people who have been infected with the virus that causes COVID-19 can experience long-term effects from their infection known as post-COVID conditions (PCC) or long COVID. Long COVID is defined as the presence of a wide range of new, returning, or ongoing health problems experienced by people after first being infected with COVID-19. Most patients’ symptoms slowly improve with time. However, for some people, post-COVID conditions may last months, and potentially years, after COVID-19 illness.

Anyone who had COVID-19 can develop post-COVID conditions, including people who had mild to no symptoms from COVID-19. Long COVID can happen to people in any age group.

People with post-COVID conditions often have fatigue, shortness of breath, coughing, joint pain, and/or chest pain weeks or months after having COVID-19. Other symptoms may include:

• Problems with memory and concentration (brain fog)
• Ringing ears, earaches
• Difficulty sleeping (insomnia)
• Fast heart rate or palpitations
• Dizziness on standing (lightheadedness)
• Changes in menstrual period cycles

The best way to prevent post-COVID conditions is by taking precautions to prevent COVID-19. This includes staying up to date with COVID-19 vaccines and wearing a face mask that has both good fit and good filtration, such as an N95, KF94, or KN95 facemask. You can prevent COVID-19 by:

• Getting your COVID-19 vaccines when they are due
• Wearing a well-fitting facemask indoors and in crowded outdoor spaces
• Washing your hands frequently
• Ventilating indoor spaces and socializing outdoors when possible
• Following public health travel guidelines
• Staying home and getting tested if you are sick, even if you are fully vaccinated

If you have mild COVID-19 symptoms, isolate at home and take over-the-counter cough/cold medication. Schedule a telehealth visit to discuss your symptoms and to arrange testing and/or treatment. Go to urgent care only if you have:

• Trouble breathing
• Persistent pain or pressure in the chest
• New confusion
• The inability to wake or stay awake
• Pale, gray, or blue-colored skin, lips, or nail beds, depending on skin tone

Follow schools’ recommendations regarding requirements for testing and return to school requirements.

In general, children that are exposed to COVID-19 should monitor for symptoms of COVID-19 and isolate if symptoms develop.

They should be tested immediately following knowledge of exposure and tested again on day 3-5 after exposure. Parents of exposed children will not be exposed unless the child becomes positive.

Follow schools’ recommendations regarding requirements for testing and return to school requirements. In general, children that are exposed to COVID-19 should monitor for symptoms of COVID-19 and isolate if symptoms develop.  They should be tested immediately following knowledge of exposure and tested again on day 3-5 after exposure. Parents of exposed will not be exposed unless the child becomes positive.

Yes, the CDC and American College of Gynecology has strongly recommended COVID-19 vaccination during pregnancy, after delivery and while breastfeeding. There is overwhelming data supporting that COVID-19 is extremely safe and improves outcomes in pregnant/post-partum women and the babies they are carrying.

Everyone should continue to follow local and state rules and regulations. In addition, everyone should comply with the practices of businesses that continue to require masks. This is particularly important in indoor settings where vaccinated and unvaccinated people may interact. 

Masks are recommended for everyone visiting an AltaMed facility, even those who have been fully vaccinated.

If you are fully vaccinated you have a low risk of contracting COVID-19 or spreading it to others. You can resume normal activities without wearing a mask, with some notable exceptions. Additionally, vaccinated people should continue to follow local and state regulations, including individual business (such as retail stores and restaurants) and workplace requirements, which may differ from CDC guidance depending on local scenarios and transmission rates.

While COVID-19 vaccines are highly effective, no vaccine provides 100% immunity. Even with new and evolving guidance, fully vaccinated individuals may make the personal decision to continue to wear a mask based on their own risk assessment and preference. Those with certain medical conditions such as immunosuppression should consult their physicians regarding the continuation of mask wearing and other protective measures.

Masks offer an extra layer of protection for those that are not vaccinated or not fully vaccinated. A well-fitted mask is recommended in public settings or when visiting people who don’t live in their household, especially in crowded indoor settings. Unvaccinated people are more protected when they practice social distancing or when they are at small outdoor gatherings where all other guests are fully vaccinated. You are not considered fully vaccinated until two weeks have passed since your final vaccine recommended for Pfizer, Moderna, Novavax or Johnson & Johnson vaccines.

Visit the CDC website to learn more emerging variants.

It is normal for a virus to mutate and change over time. Sometimes these new variants emerge and disappear. Other times, new variants emerge and stay. New variants and strains of the virus that causes COVID-19 have been documented all over the world. So far, studies suggest that the COVID-19 vaccine is effective in protecting you from these new variants. Scientists and doctors continue to study COVID-19 and update the vaccines to improve their effectiveness. Continue to follow the guidance set by your local public health department when there are surges in your community.

Myocarditis is inflammation of the heart muscle, and pericarditis is inflammation of the outer lining of the heart. The symptoms are chest pain, shortness of breath, or an abnormal heartbeat (fast, fluttering, or pounding). Although these are both rare, there have been reports of myocarditis or pericarditis in adolescent and young adult males after receiving their COVID-19 mRNA vaccines (Pfizer or Moderna). Most patients who received care quickly felt better.

The CDC still recommends the COVID-19 vaccination for everyone 6 months of age and older. The benefits of COVID-19 vaccination outweigh the risks, including the possible risk of myocarditis or pericarditis.  Please visit the CDC’s page on Myocarditis and Pericarditis After mRNA COVID-19 Vaccination for more information.

Guillain Barré Syndrome (GBS) is a neurological disorder that damages nerve cells and causes muscle weakness. Although some people who received the J&J/Janssen COVID-19 reported GBS, it is very rare. Please see the CDC’s page on Select Adverse Events Reported after COVID-19 vaccination to learn more.