UC Davis Health is scheduling COVID-19 vaccines

Get the latest on how to schedule your COVID-19 vaccine, boosters and third doses, and more.

The Omicron variant is causing high demand for testing, making it difficult to get COVID-19 testing appointments and at-home tests. Due to high numbers of COVID-19 infections, more patients than usual are contacting us for testing and other services. This is extending wait times and delaying responses via phone and messages through MyUCDavisHealth.

For the health and safety of others, if you've been exposed to someone with COVID-19 or have COVID-19 symptoms and are waiting for a test or your results, stay home and isolate from others.

If you're vaccinated, wait to get tested until day 5 after your last exposure to someone with COVID-19, according to the CDC. (The day of exposure is day 0.) Testing before day 5 is likely to be too soon to indicate if you have developed, or will develop, an infection. During the five-day period, stay away from other people, including those you live with. Wear a well-fitting mask at all times if you must be around other people. If, after day 5, you test negative, you should continue to wear a well-fitting mask until day 10.

Testing isn’t critical if your COVID-19 symptoms are mild. If you develop symptoms that are difficult to manage, but not that serious, call your primary care provider or seek urgent care. Contact your health care provider or consider going to the emergency room if you develop severe coronavirus symptoms.

Your health care provider can best advise you about the need to be tested for COVID-19. Testing is encouraged if you have COVID-19 symptoms or were recently exposed to someone who tested positive for the virus.

Health experts caution that COVID-19 tests only tell you what your status is for that exact moment in time. For example, you could have been exposed to the virus a few hours before testing but haven’t reached the viral level that can be detected by a COVID-19 test.

The CDC recommends people who are vaccinated do NOT get tested until at least 5 days after your last contact with a COVID-19 positive person. If you develop symptoms, get tested immediately and isolate until you receive your results. If you test positive, follow isolation recommendations.

View the CDC's full quarantine and isolation guidelines for vaccinated and unvaccinated people

View a list of COVID-19 symptoms you should watch for

Find a COVID-19 testing site in California near you

You can find a COVID-19 testing location near you through the state of California’s COVID-19 website.

You can view individual county testing resources as well:

UC Davis Health patients and non-patients with COVID-19 symptoms can contact a doctor through UC Davis Express Care or by contacting your primary care provider by phone or MyUCDavisHealth. A doctor can help quickly coordinate a COVID-19 test, possibly at a UC Davis Health drive-up site in Sacramento, which are available seven days a week.

Access UC Davis Express Care for patients

Access UC Davis Express Care for non-patients

Healthy Yolo Together, a public health project of UC Davis, also provides free saliva-based COVID-19 testing at locations in Yolo County.

Read more from UC Davis Health: More options than ever for at-home and community COVID-19 tests

If possible, check different testing sites and try to be flexible in terms of when and where you are willing to go.

If you have COVID-19 symptoms, you should isolate until you can get tested. Rapid antigen at-home tests are useful to determine whether you’re infectious. It's also best to take rapid tests on two consecutive days.

The CDC recommends people who are vaccinated:

  • Do NOT get tested until at least 5 days after you last had contact with a COVID-19 positive person.
  • Stay home and away from other people for those 5 days (day 0 through day 5) after your last contact.
  • Wear a well-fitting mask when around others at home.
  • For 10 days after your last close contact with someone with COVID-19, watch for fever (100.4◦F or greater), cough, shortness of breath, or other COVID-19 symptoms.

If you can't get a test five days after a close contact with someone with COVID-19 and never have had symptoms, you can leave your home after day 5. Wear a well-fitting mask for 10 days after your date of last close contact when around others at home and in public.

If you had a confirmed exposure to someone with COVID-19, stay away from other people (including those you live with), for 10 days after your last close contact with that person.

Learn more about the different types of COVID-19 tests available

If you were exposed to someone who tested positive for COVID-19, are up-to-date with your vaccinations OR had confirmed COVID-19 in the past 90 days, and don't have COVID-19 symptoms:

  • You do not need to quarantine.
  • Get tested at least 5 days after your close contact with someone with COVID-19, even if you don't develop symptoms.
  • Watch for fever (100.4◦F or greater), cough, shortness of breath, or other COVID-19 symptoms for 10 days after your close contact with someone who has COVID-19,
  • Isolate immediately and get tested if you develop symptoms.
  • Wear a well-fitted mask for 10 days when around others in your home or in public.

If you were exposed to someone who tested positive for COVID-19 and are not up-to-date with your COVID-19 vaccinations, but are asymptomatic:

  • Stay home and quarantine for at least 5 days.
  • Wear a well-fitting mask if you must be around people in your home.
  • Get tested even if you don't develop symptoms, at least 5 days after your exposure to someone with COVID-19.
  • Watch for fever (100.4◦F or greater), cough, shortness of breath, or other COVID-19 symptoms for 10 days after your exposure.
  • Isolate immediately and get tested if you develop symptoms.
  • Wear a well-fitted mask for 10 days when around people in your home or in public.

View the CDC's full quarantine and isolation guidelines

Learn how to get your COVID-19 vaccine at UC Davis Health

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A diagnostic test, known as a molecular PCR test, uses a nasal swab and collects samples of cells and fluids from your respiratory system. It enables the identification of specific genes for the SARS-CoV-2 virus that causes COVID-19. The specimen is collected using a long nasal swab that is inserted into the passageway between the nose and the back of the throat. PCR tests, like the ones used by UC Davis Health's lab, are close to 100% accurate in diagnosing COVID-19 infection, but the disadvantage is they take a little more time for results.

Rapid antigen tests account for most of the rapid diagnostic tests. These are done with a nasal or throat swab and looks for a protein that’s part of the virus. Antigen tests are less expensive and have a generally quicker turnaround time, sometimes within 15 mins. However, they are less accurate because if a person is not near peak infection, but still contagious, the tests may come back negative. The CDC advises people who show COVID-19 symptoms but test positive with an antigen test to get a PCR test to confirm results.

An antibody test, also known as a serology test, is done with a blood sample that may identify past infection of the virus that causes COVID-19. It’s a test that looks for evidence of the body’s immune response to the virus. Antibodies are detected in the blood after an infection. However, with COVID-19, we don’t fully know what the presence of its antibodies means yet.

Learn more about the different types of COVID-19 testing

To determine which test you should take, know why you’re being tested.

If a rapid test is more available or convenient, it’s a good idea to use it. If it’s positive, you can rely on the result. Rapid antigen tests are now being used at schools for rapid screening. They are good for this purpose. Or maybe your child has been exposed at school, and after quarantining per the CDC guidelines, they need to have two negatives tests. So, the parents may want to buy a rapid antigen home kit.

But in other instances, if the rapid test is negative, particularly if you suspect infection, it’s best to get a molecular PCR test to double-check since the PCR test is more sensitive. A PCR test can be used for asymptomatic testing or to confirm a positive antigen test. It’s also used when patients have symptoms, need to be tested before a procedure, or when they are being admitted to the hospital. PCR tests are often used to make clinical decisions.

With all home-use tests on the market, whether antigen or PCR, following testing instructions is very important to ensure the quality of testing. For example, if a swab isn’t inserted deep enough into the nose, it may not collect a good sample for testing and may give a false negative.

Read more from UC Davis Health: More options than ever for at-home and community COVID-19 tests

COVID-19 tests are free at testing sites. If you’re insured, you can get a COVID-19 test from your health provider or any out-of-network provider. If you don’t have insurance, the government pays for your test.

Asymptomatic testing means getting tested when you don’t have any COVID-19 symptoms and don’t feel sick. Although it might seem pointless to get tested when you are fine, asymptomatic testing has been a key strategy in tackling the pandemic. It can identify people who may be carrying the COVID-19 virus and are spreading it but don’t know they’re infected. Most asymptomatic people develop symptoms later on.

Especially if you are unvaccinated, you should be tested for COVID-19 even if you’re asymptomatic. Additionally, asymptomatic testing is required for unvaccinated people in certain workplaces, including at any University of California (UC) campus, and to attend certain events, like concerts and sporting events.

Even if you are vaccinated against COVID-19, experts still recommends asymptomatic testing. However, the latest CDC guidelines also recognize that there is a shortage of testing and it may be hard to find a test.

If you test positive for COVID-19, you should contact your health care provider right away. You should also notify any people who were recently around you so they can watch for symptoms and get tested if needed.

There are over-the-counter PCR testing kits for at-home use. You can purchase them online, take the test, and mail it in. Results come back in about 48 hours. Amazon even has their own PCR test that provides results within 24 hours of their lab receiving it.

Read more from UC Davis Health: More options than ever for at-home and community COVID-19 tests

Rapid antigen tests search for protein pieces from the virus and are known to be less sensitive than molecular PCR tests. These COVID tests perform best with people in the early stages of COVID-19 infection, when viral load is the highest.

No test is completely accurate, which means that some cases will be missed (false negatives) and some people will be told they have the virus when they don’t (false positives). Positive tests tend to be accurate, but negative tests need to be interpreted with caution, especially in a high-risk setting or when used on asymptomatic people.

Rapid antigen tests are best used as intended, where a person tests at least twice over a 36- to 48-hour period to increase the odds of detecting an infection.

View the FDA’s list of over-the-counter antigen tests that have been authorized for emergency-use authorization

Learn more about COVID rapid tests

UC Davis Health has rolled out a groundbreaking, highly accurate test that can check for both COVID-19 and flu viruses at the same time, returning results in 20 minutes. We are the first in the region and among the first in the nation to use these rapid, combined molecular tests at the point of care.

For now, the combined COVID-19 and flu tests will be limited to the emergency department or situations when speed is critical to understand a patient’s condition. Fast, accurate flu and COVID-19 results can help with management and treatment of both viruses. They can also eliminate hours or sometimes days of anxiety for patients.

Read more about the rapid test for flu and COVID-19

Learn more about COVID rapid testing

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Yes. Our clinical laboratory began internal testing in March, 2020, using CDC assays (tests to determine the presence of infectious agents like COVID-19).

At the same time, we developed high-throughput assays on the Roche Diagnostics cobas® 6800 System to meet an expected surge in cases. The commercial device has the capacity to perform more than 1,000 tests per day.

We don’t really know what the presence of COVID-19 antibodies means. It doesn’t necessarily mean that you’re immune to the virus. Medical science has yet to determine what level of antibodies confirm immunity, if immunity is possible, or how long immunity might last. The result of a positive antibody test indicates past infection and/or immunization, but may not correlate with immunity.