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COVID-19 Testing Options: What you need to know about PCR, Antigen, and Antibody Tests

June 3, 2021

As we head into the winter season with COVID-19 cases and hospitalizations rising, adequate testing will be instrumental in the ability of clinical practices, businesses, and schools to safely remain open.

Orca Biotech has partnered with FDA / EUA approved companies and CLIA-certified labs to provide reliable and accessible COVID-19 testing solutions.

As providers and businesses consider which tests to provide or recommend, we’ve put together answers to FAQs about current COVID-19 testing.

What types of tests are currently available?

As of December 2020, there are three kinds of available FDA / EUA approved testing solutions for healthcare providers and patients: PCR, antigen, and antibody tests. Each test provides distinctly different advantages and considerations due to collection methods, processing, sensitivity/specificity, costs, and turnaround time.

Orca Biotech offers all three of the following test types to qualified practitioners:

  • FDA / EUA approved Saliva PCR Test
  • FDA / EUA approved Rapid Antigen Test
  • FDA/ EUA Rapid Antibody Test

What is the difference between the PCR test, antibody test, and antigen test?

PCR Test: Any type of PCR test, whether nasal swab or saliva, tests for the genetic material of the virus. If the virus is reproducing in a patient, a PCR test is sensitive to detecting the virus and specific in identifying those who are negative.

This test requires patient samples to be collected and transported to a CLIA-certified processing lab. There, the samples undergo an RNA amplification process called Polymerase chain reaction, or PCR. Finally, the PCR process amplifies the possibly infected RNA to allow detection of the COVID-19 virus.

Antigen Test: This test detects specific proteins, known as antigens, on the surface of the virus and can identify people at the peak of infection when virus levels in the body are likely to be high.

Rapid antigen tests can provide fast results onsite without the need for specimen transportation and lab processing. However, antigen tests are not as sensitive as PCR tests, with ranges varying from 84%-97.6%. Detection rates drop after 5-7 days of symptom onset. Therefore, antigen tests may miss many who are infected but tested when their viral load does not meet the threshold of detection. Negative results may need to be confirmed by a PCR test if a patient is experiencing symptoms after a known exposure. 

Antibody Test: Research on COVID-19 antibody behavior is still under development, but most medical professionals believe these antibodies may remain in your bloodstream for up to 4-6 weeks after exposure.

The COVID-19 antibody test uses blood to detect the presence of antibodies associated with the virus. Although antibodies do not give a person full immunity from the virus, the detection of antibodies can provide a useful clue into the spread of the disease and a reasonable explanation for past symptoms.

It can take a person’s immune system 2 to 3 weeks to form antibodies, so this test will not be positive in the early phases of the virus.

                                   

Which is the diagnostic test?

The PCR test is the gold-standard diagnostic test with the highest accuracy. It is the test often required before clinical procedures or surgery and for proving negative status for travel or sports participation as it has the most accurate sensitivity and specificity. The most significant consideration associated with this test is the need for laboratory processing and turnaround time for receiving results.

Though also used as a diagnostic test with the advantage of rapid onsite results, Antigen tests can detect only high amounts of virus and are less sensitive than PCR tests. They are most accurate when the viral load is highest and patients are most likely to spread the virus.

In contrast, an antibody test is a screening tool. As it can take two to three weeks after initial infections to develop enough antibodies for detection, antibody tests can only be used as a screening tool or to identify previous infections.

What is the difference between saliva-based PCR tests and nasopharyngeal-swab PCR tests?

The primary difference between these two tests is the method of specimen collection. Both tests use the same polymerase chain reaction testing technology that detects the genetic material of the virus. Both tests boast excellent specificity and sensitivity.

Saliva-based tests require patients to simply spit into a collection kit, while nasal-swabs require a medical professional to insert a long swab into a patient’s nose.

Though less widely available, saliva-based tests present many advantages over nasal-swab collection:

  • Saliva tests are self-collected and negate the need for direct interaction between healthcare workers and patients. This eliminates bottlenecks in the testing process, decreases exposure for healthcare workers, and requires less PPE per CDC requirements.
  • Saliva collection kits reduce the chance of user collection error in sample collection.
  • Saliva collection kits inactivate the live virus after pain-free self-collection while preserving and stabilizing viral RNA transcripts over 10 days with no degradation of sample efficacy.
  • Saliva specimens have no storage or transportation temperature requirements and are easier to transport to the testing laboratory.
  • Saliva tests are more comfortable for patients, which can increase patient willingness to be tested.

How do patients access test results for PCR tests?

As with all patient medical information, diagnostic results should only be provided through secure, HIPAA compliant platforms.

Orca provides a secure, easy-to-navigate platform for all patient-facing software, including diagnostic test results. Providers can also share educational content and send surveys regarding patient health and COVID-19 through our secure platform.

With the many new organizations and labs providing testing services, providers and businesses should evaluate companies’ ability to handle protected health information (PHI). Orca Health has extensive experience in both collecting and sending patient information securely. Both privacy and security are of paramount importance to our company and those we serve.

What does the sensitivity of a test refer to?

Sensitivity is the proportion of people with the virus who have a positive result.  A highly sensitive test is successful in correctly identifying patients with the virus.

What does the specificity of a test refer to?

Specificity is the proportion of healthy patients that do not have the disease who test negative. It identifies the ability of the test to correctly identify patients without the virus.

What is an EUA?

The United States (U.S.) FDA has made these tests available under an emergency access mechanism called an Emergency Use Authorization (EUA). The EUA is supported by the Secretary of Health and Human Service’s declaration that circumstances exist to justify the emergency use of in vitro diagnostics (IVDs) for the detection and/or diagnosis of the virus that causes COVID-19.

An IVD made available under an EUA has not undergone the same type of review as an FDA-approved or cleared IVD. The FDA may issue an EUA when certain criteria are met, such as no adequate, approved, available alternatives and (based on the totality of scientific evidence available), a reasonable belief that this IVD may be effective in the detection of the virus that causes COVID-19. The EUA for this test is in effect for the duration of the COVID-19 declaration justifying emergency use of IVDs unless terminated or revoked (after which the test may no longer be used).

Are these tests covered by insurance?

As of March 18 and lasting for the duration of the public health emergency, all FDA- approved COVID-19 Diagnostics Tests are covered by insurance providers with no cost-sharing as long as the test is deemed medically appropriate by an attending health care provider.

What is the cost for patients without insurance?

Patients without insurance can be tested with the Federal Government covering costs under Medicare. There are also cash pay options available for those who choose to opt-out of insurance billing or choose to be tested for screening purposes.

How do I order COVID-19 tests?

Please fill out the following short form and a representative will contact you about your order.  

(SUBMIT REQUEST)

Where can I go for updates and more information?

CDC webpages:

General

Healthcare Professionals

Information for Laboratories

Laboratory Biosafety Guidelines:

Isolation Precautions in Healthcare Settings:

Specimen Collection:

Infection Control: https://www.cdc.gov/coronavirus/2019- ncov/infectioncontrol/index.html

FDA webpages:

General

EUAs

Additional References:

Interim Guidelines for Collecting, Handling, and Testing Clinical Specimens from Persons for Coronavirus Disease 2019 (COVID-19). Centers for Disease Control. URL

Interim Guidance for Rapid Antigen Testing for SARS-CoV-2. Centers for Disease Control. URL

Interim Guidelines for COVID-19 Antibody Testing in Clinical and Public Health Settings. Centers for Disease Control. URL

Coronavirus Disease 2019 Testing Basics. US Food and Drug Administration. URL

Interpreting a Covid-19 Test Result. J Watson GP et al. BMJ: British Medical Journal. URL

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