In general, there are two categories of different lab tests that test for COVID-19: Molecular tests, which look for evidence of active infection; and Serology tests, which look for previous infection by detecting antibodies and are mainly used for investigational purposes and not for diagnostic purposes. According to Dr. Evans, the three main types of tests within these categories include, “the molecular, the antigen, and the antibody tests.” 
 
According to Dr. Delaune, “Molecular tests are looking for the core of the virus, the DNA, that is by far the most accurate to detect an active virus as you are looking for the virus particle. This type of test is generally conducted by collecting saliva or mucus from the back of the throat and usually takes a couple days to get a response. It is the most accurate form of testing. If it comes back positive, you have COVID-19 and if it comes back negative, you probably do not have COVID-19.” 
 
Dr. Delaune continued to explain that “rapid tests are frequently used in the emergency department and these tests are one of the initial tests conducted when diagnosing patients as results can be determined within an hour of conducting the test. Instead of checking for the core of the virus, these tests are checking for the parts of outer shell of the virus to see if antigens exist. Personally, we have seen a lot of cases where this test comes back negative and, if we still hold a strong suspicion for COVID-19, then we run a molecular test which may be positive. This test is conducted by taking a swab in throat or the back of the nose, much like the PCR test, but quicker and easier to do. These are the two ways to check for active infections.” 
 
As far as testing for the body’s response to COVID-19, Dr. Delaune explains that, “the antibodies test is far more effective for seeing if immunity for the virus exists. This is not testing for the active infection; it is testing for your body’s response. Therefore, if this person has had COVID-19 at some point, this testing can be used, but it takes days, weeks, and even months for the body to develop antibodies. This test is worthless to check for an active infection, but if it comes back positive, it implies that your body has been exposed to the virus.” 

Not much information about reinfection and the immune response, including duration of immunity to COVID-19 infection is currently available according to the United States Centers for Disease Control and Prevention (CDC). Patients infected with other betacoronaviruses (MERS-CoV, HCoV-OC43), the genus to which SARS-CoV-2 belongs, are unlikely to be re-infected shortly (e.g., 3 months or more) after they recover. 
 
Dr. Delaune confirms that there are not many confirmed cases of reinfection and shares, “Presumably what happens is that after you survive infection, your body builds antibodies that attack infection when you get it again, assuming the exposure is to the same or a very similar virus as your body identifies the antigen. For example, the flu changes from year to year and the antibodies change as well, so you need a new vaccine every year but the same cannot be said about the coronavirus because it has not been around for that long to mutate. Alternatively, there is also the possibility that antibodies may not last very long in patients with coronavirus. A year from now they could be gone and if you are exposed now, the body will have to go through the process of making those antibodies again. We are still new to the game.” 
 
Dr. Delaune added that there may be some immunity to the coronavirus as, “a treatment called convalescent plasma therapy was recently approved by the United States Food and Drug Administration (FDA). The treatment takes plasma (the fluids) from the blood of a recovered patient of COVID-19 and injects it into someone who is very sick. The plasma has antibodies which can help a sick patient feel better. The fact that they are using convalescent plasma proves that there is some immunity involved in people who have had COVID-19 and their blood can be used for antibodies.” 

When sharing living space with someone who has been infected or exposed to COVID-19, you should follow the same procedures as you would follow while you are out in public. Dr. Delaune confirms, “You have to avoid any contact with the air they breathe, any fluids they may spread through cough, and be careful about common surfaces in case they have touched anything. This may be harder to do as you are sharing the same space, but still be careful about getting droplets from their cough into your eyes, nose, or mouth.”  
 
Dr. Evans adds that the best method for avoiding an infected person sharing the same household is, “strict isolation and keeping yourself and others away from the infected person of the household. It means going to an isolated part of the house, staying in a room that is isolated from everyone else, maintaining the 6-foot rule, and cleaning all frequently touched surfaces.” 
 
If two people have tested positive for the coronavirus, Dr. Jim Evans confirms that, “it is alright to quarantine together as long as you stay away from everybody else.” Dr. Delaune mentions, “similar to chickenpox, you do not need to isolate yourself as it should not worsen the case of coronavirus, but you should extend the quarantine period until both people have tested negative for the virus in case someone is a carrier. It’s fine to share everything when you already have the germ.” 

COVID-19 is unlike other respiratory viruses known to humans, but in time it could evolve into a seasonal scourge like the flu. The scenario depends on many unknowns and assumes the new coronavirus will bend to weather factors. This would not happen until enough people have been exposed to the virus -- or vaccinated -- to provide a level of herd immunity. Until scientists know for certain how the weather will affect SARS-CoV-2, people must continue to apply strict prevention measures.
 
To people who may feel a sense of boredom or exhaustion over COVID-19 measures, Dr. Delaune suggests, “we need to appeal to people’s sense of community. A lot of what we are doing is not to protect ourselves, but to protect others. Children at school may complain about wearing a mask. I explain to my kids that they are not wearing their masks for their own safety. They are young and healthy and will probably not get sick. And if they do get sick, they will be fine. They are wearing masks to protect their teachers and should think about the people that can get infected because of them.” Dr. Evans adds that this fall, “people need to especially stay away from vulnerable groups and older adults. Children are less likely to get severely sick, although there may be some cases. However, elderly adults are at a much greater risk from this illness.” 
 
To best prepare for this unique fall season, Dr. Delaune recommends “people get their flu vaccine this year. One way we can diagnose a patient with coronavirus is by eliminating the possibility that they are sick with the flu. Symptoms between the flu and COVID-19 are very similar. If a patient has been vaccinated for the flu, then we know we’re certainly looking at the coronavirus. Getting vaccinated will help healthcare providers clear up the confusion from the get-go. We can diagnose and respond with appropriate treatment more quickly.” 

Dr. Eugene Delaune practices Emergency medicine in multiple U.S. states and serves as one of the Consulting Medical Directors for Global Travel Plus, where he is actively involved in the review of medical reports and the planning of critical medical transports. He has medical licenses in 8 states, was trained by NASA as a landing-site Physician to care for astronauts in the event of an emergency landing at a TAL site, and was certified by the U.S. Air Force as a Critical Care Aeromedical Transport Team (CATT) Physician. He is a native English speaker and is fluent in German.


Dr. James Evans practices Emergency medicine in multiple U.S. states and serves as one of the Consulting Medical Directors for Global Travel Plus, where he is actively involved in the review of medical reports and the planning of critical medical transports. Dr. Evans brings an extensive experience both as medical escort and also giving direction to medical cases as an Assistant Medical Director. Dr. Evans exploits his international medical knowledge to present at several local, regional and national conferences, including lectures on "Pandemic Influenza" and "Global Crisis Management."