New York Institute of Technology
Dear Students, Faculty, and Staff:

With the emergence of COVID-19, many immunology terms used by the media and the general public may lead to misunderstanding and confusion. Two such terms are “antigens” and “antibodies.” This week’s message will attempt to clarify the differences.

Antigens are defined as toxins or other foreign substances that induce an immune response within the body. Bacteria, fungi, or viruses entering the human body may cause the body to elicit an immune response to the foreign entity. The antigen is the specific molecular structure that elicits the immune response. One type of response to this foreign invader is the production of human antibodies (or proteins called immunoglobulins) that can attach to the invading foreign body to facilitate its destruction or removal from the body. The terms “antigen” and “antibody” are commonly used in COVID-related testing.

An “antigen test” is essentially looking for parts of the SARS Cov-2 virus (which causes COVID-19). If these viral parts, or antigens, are found, this is evidence that the virus has infected an individual and the person is considered to be COVID-positive and possibly infectious. Therefore, this test is classified as a diagnostic test.

On the other hand, there is also an “antibody test,” which looks for the antibodies produced by the human body in response to SARS-Cov-2 entering the body. Looking for antibodies to invading organisms is classified as serology testing. This information can be very helpful when the presence of antibodies has been proven to be protective against future infections. For example, to gain entry into college, all students must demonstrate immunity or antibodies against measles. If the student has no antibodies, they must be vaccinated. This model would be the gold standard for managing SARS Cov-2 as well.

However, there are many hurdles to overcome. First, COVID-19 antibodies have not always been found in patients post-infection, and, if present, have not yet been proven to provide ongoing protection. Although rare, patients have been re-infected with SARS Cov-2. Second, there may be cross-reactivity between SARS Cov-2 antibodies and the antibodies to other routine coronaviruses (like the coronaviruses that cause the common cold). Therefore, interpreting the results of an antibody test may be difficult. Third, we do not yet have a vaccine proven to be effective, although a lot of research is taking place in this area. The current expectation is that, optimistically, a vaccine will be available in 2021.

More in-depth information on antibodies, immunity, and antibody testing can be found on the
Centers for Disease Control and Prevention website.

We still have more to learn about this novel coronavirus. In the interim, we must continue with our preventative behaviors, including mask-wearing, physical distancing, and proper hand-washing hygiene.

  • Flu season is here. We strongly encourage you to get your flu vaccine as soon as possible at our Academic Health Care Center or through another source, including urgent care facilities, drug stores, and health care providers.
  • Random free COVID testing, as required by our campus reopening plans, will take place on the Long Island campus on October 20 and on the New York City campus on October 21. Please allow extra time when traveling to campus on those days in case you are selected for testing.
  • The New York Tech community is also welcome to make an appointment for a COVID test at the Academic Health Care Center on our Long Island campus by calling 516.686.1300.
  • For those who may continue to feel anxious or uneasy, please reach out to Counseling and Wellness Services at our campuses in Long Island (516.686.7683) or New York City (212.261.1773) to talk or make a virtual appointment.

Brian L. Harper, M.D., M.P.H.
Chief Medical Officer, NYIT College of Osteopathic Medicine

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