We are all becoming more knowledgeable about COVID-19 as the pandemic continues. But, of course, there are so many more questions – some we have answers to and some we will learn in time. Alan Loren, M.D., PhD, Chief Medical Officer and Executive Vice President, and Guy Kochvar, M.D., an Infectious Disease Specialist, help answer some of our readers’ questions below.
Q: If a person has had and recovered from COVID-19, can they get it again?
NCH: The short-term risk of reinfection (within 90 days) appears to be low. However, sporadic cases of reinfection have been recently documented. Because of limited community testing and surveillance, we don’t know how frequently reinfection occurs.
Q: If a person has had COVID-19 and tests positive for antibodies, but is exposed again, are they contagious for a short period of time? Or are they totally immune and not at risk of spreading the virus?
NCH: Our understanding of immunity and COVID-19 reinfection is still evolving. The small number of confirmed cases of reinfection and the limited number of research laboratories capable of safely culturing this virus have limited scientists’ ability to study viral shedding with reinfection. Studies in this area are ongoing, but at this time we cannot give a certain answer to this question.
Q: My adult niece had a mild case. Felt like a cold, no fever but loss of taste and smell at one point. Do we know yet if all cases of COVID-19 are expected to have lingering long-term tissue damage, to the lungs or otherwise? Or is it only in cases of severe infections that require ICU care?
NCH: Our understanding early in the pandemic was that recovery time was approximately two weeks for mildly symptomatic infections and three to six weeks for severe infections. However, we have since learned that COVID-19 can result in prolonged illness even among persons with milder illness, including young adults. In a study published by the Centers for Disease Control and Prevention (CDC), of 292 patients diagnosed with COVID-19 in an outpatient setting, approximately one third reported not returning to their usual state of health within two to three weeks of diagnosis. Even among those aged 18 to 34 with no chronic medical conditions, nearly one in five reported that they had not returned to their usual state of health 14 to 21 days after testing. Older age and the presence of multiple chronic medical conditions were associated with prolonged illness. Symptoms that were most likely to persist beyond 14 to 21 days included cough and fatigue.
In a similar study of 143 patients who were hospitalized for COVID-19 in Italy, only 13% were symptom-free after an average of 60 days following onset of illness. The most common ongoing symptoms were fatigue, shortness of breath, joint pain and chest pain. Other studies have reported prolonged problems with memory and difficulty concentrating.
Although data is limited, some studies have shown evidence of ongoing respiratory impairment in limited numbers of patients. Cardiac complications can range from mild elevation of cardiac enzymes without signs of acute heart failure to new-onset heart failure.
Q: Has the medical community decided for sure that it can’t be transmitted to our pets? At one point I had read that cats could get it, but we haven’t heard any follow-up on that.
NCH: Although COVID-19 is thought to have originated from bats, animals are not thought to be a major source of infection to humans. Thus far there have been no reports of domesticated animals transmitting infection to humans. A small number of cats and dogs have been reported to be infected after contact with people with COVID-19. Dogs appear to be less susceptible to infection in experimental settings. Mink appear to be highly susceptible to this infection with outbreaks reported on mink farms in the U.S. and Europe, including suspected transmission from mink to human. Investigations are ongoing by state and federal health and agriculture authorities. The CDC recommends that pets be kept away from other animals or people outside of the household and that people with confirmed or suspected COVID-19 avoid close contact with household pets for the duration of their isolation period.
Q: Is it known yet, once injected, how long vaccinations work? Will it be an annual vaccine like the flu, or will it work longer term like a mumps vaccine?
NCH: These are all important questions; however, we won’t know how long immunity from a vaccine lasts until we have more experience and data.
Q: Is it expected that it will be a regular mutating virus like the flu, so it’s here to stay seasonally with regular mutations? Or will it be something that could be vaccinated into near-extinction, like the measles?
NCH: SARS-CoV-2 is a virus that produces RNA as its genetic material. RNA viruses develop mutations over time as they are copied inside their host, although coronaviruses change more slowly than many other RNA viruses such as influenza. Also, at this point in the research no major mutations have been seen where the virus attaches to the hosts cells. However, it’s too early to say with certainty whether this virus will become seasonal like the common cold coronaviruses or influenza.
Q: A friend of mine had COVID and the doctor told her she would be immune for about three months afterwards. The CDC didn’t tell her the same thing. Is there a grace period after getting it when you truly can’t get it again?
NCH: According to the CDC, available evidence suggests that most people who recover from COVID-19 will have a degree of immunity for at least three months. Reinfection with COVID-19 is possible but most likely uncommon within this three-month period. If this person has a new exposure to someone with confirmed COVID-19 during that three month period and continues to follow current safety measures to prevent SARS CoV-2 transmission (i.e., use of mask, social distancing, handwashing), then that person does not require quarantine or repeat testing after the exposure. However, if they develop new symptoms consistent with COVID-19 within 14 days of the new exposure, consultation with a healthcare provider is recommended.
Q: What is the latest information about the newly developed vaccine and the tentative roll-out plan?
NCH: There are currently nine vaccine candidates with published results from phase 1–3 clinical trials, with many additional vaccines currently under development. Preliminary results from phase 3 clinical trials of two vaccine candidates were recently reported in press releases by the companies Pfizer and Moderna. Both vaccines utilize a new technology that instructs cells to make viral proteins that stimulate a person’s immune system. Both vaccines are given in two doses. Both trials have enrolled more than 30,000 participants with no significant safety concerns reported to date. Each trial has reported approximately 95% vaccine efficacy in preventing COVID-19 following the second dose. Each vaccine must be shipped and stored at low temperatures. On November 20, Pfizer submitted an emergency EUA application to the U.S. Food and Drug Administration (FDA) for approval of its vaccine, and the FDA has scheduled a meeting of its vaccines advisory committee to discuss this application on December 10.
The Illinois Department of Public Health is actively planning for the administration of COVID-19 vaccines, once they are approved, based on guidance from the federal government and the CDC.
Q: I hear many different things about testing and wonder why some people can get regular testing and others can’t. For example, I have heard that tests are only accurate if you are having symptoms. I have also heard that some restaurants will do rapid testing on all patrons. And I know that the University of Illinois is testing everyone on campus twice a week ― with or without symptoms. There is so much contradictory information, and with the holidays coming it would be nice if could to be tested before gatherings. But it seems like the rules and guidelines for testing are very inconsistent!
NCH: We understand that with so much COVID-19 flooding the news each day, it is difficult to understand the rules and guidelines. Here are the recommendations from the Infectious Diseases Society of America:
- all individuals with COVID-19 symptoms should be tested
- asymptomatic individuals who have had known or suspected contact with a COVID-19 case should be tested
- asymptomatic individuals should be tested when the results will impact isolation/quarantine/personal protective equipment usage decisions, dictate eligibility for surgery or inform administration of immunosuppressive therapy.
The accuracy of these tests may vary, based on the specific type of test used, the timing of the testing, and the sample collection site. Since the test measures the detection of the COVID-19 virus at a single point in time, if the sample is collected too early or too late in the course of illness it may give a false negative result.
Considering all of these testing recommendations and information together is an indication of why this virus has been so difficult to contain, particularly because it is so new and the testing and treatment is new as well!
Q: Can you please touch on the different tests and who is eligible (both at NCH and common places like CVS or Walgreens)?
NCH: Two kinds of tests are available for COVID-19: viral tests and antibody tests.
Viral tests, including the Real-Time Reverse Transcriptase Polymerase Chain Reaction (RT-PCR), the rapid point-of-care (POC) molecular test (i.e., Abbott ID NOW), and the POC antigen test, are approved or authorized by the FDA and are recommended to diagnose current COVID-19 infection. The RT-PCR molecular test is the “gold standard” for detection of SARS-CoV-2. Rapid POC molecular and POC antigen tests usually provide more rapid results than the RT-PCR but have a higher probability of missing an active infection. Therefore, it may be necessary to confirm a rapid POC antigen or rapid POC molecular test result with a RT-PCR test, especially if the result of the rapid POC test is inconsistent with the clinical picture (i.e., a negative antigen test result in a symptomatic individual). Rapid antigen tests perform best when the person is tested in the early stages of infection with SARS-CoV-2 when viral levels are generally highest. They also may be helpful in situations where the person has a known exposure to a confirmed or probable case of COVID-19.
Antibody tests approved or authorized by the FDA are used to detect a past infection with SARS-CoV-2. The CDC does not currently recommend using antibody testing as the sole basis for diagnosing current infection, or for disproving a positive viral test. Depending on when someone was infected and the timing of the test, negative results may be seen in someone with a current COVID-19 infection. In addition, it is not currently proven whether a positive antibody test indicates protection against future SARS-CoV-2 infection; therefore, antibody tests should not be used at this time to determine if someone is immune.