Important Update SymbolQuestion: I read an article I believe in JACI or JACI: In Practice recently about the impact of variants on the accuracy of COVID-19 testing. The take home message was that rapid testing and even potentially PCR testing were losing accuracy. I cannot manage to find it despite looking through the last few issues. Does the task force readily have that available or aware of other literature regarding variants and the accuracy of COVID-19 testing?

Answer: There are no published reports on a loss of sensitivity of current testing against Omicron variants that are present today. There have been some reports in pre-print of some loss of sensitivity, but those have not been peer-reviewed yet. The NIH is funding research to develop a method to predict the accuracy of tests based on certain mutations, that is still in progress. At this point, there is no way to predict accuracy before the actual emergence of the variant.

The Infectious Diseases Society of America (IDSA) also has a good summary of variants and testing:

Question: Do you have any guidelines or published information re: chronic allergic rhinitis and sinusitis patients, not asthmatics, who request to work from home due to COVID-19 pandemic, who are not infected? I am getting multiple requests from teachers. Any guidance would be appreciated.

Answer: There is no evidence of any increased risk for COVID-19 among chronic allergic rhinitis or sinusitis patients. The issue is the overlap of symptoms, as we cannot clearly differentiate between COVID-19 symptoms and allergy symptoms (with the exception that sneezing isn’t a COVID-19 symptom). If patients are symptomatic, the assumption is that they could be COVID-19 positive which would require quarantine and testing. If patients are having uncontrolled allergy symptoms, their current treatment regimen is insufficient and they should be encouraged to schedule a visit with their allergist (either via telehealth or in person with a negative COVID-19 test) to optimize their treatment plan.

Question: I have had a couple patients bring in results of a Rapid Virus Panel that includes SARS-CoV-2 along with influenza and other viruses.  What is the utility in such a test for SARS-CoV-2?  Sensitivity, specificity, false positives, false negatives?  Is the test FDA-approved?

Answer: It would depend on the actual test used. The CDC does keep a list of assays that have Emergency Use Authorization for rapid detection of multiple viruses including SARS-CoV-2. For reference check out:

Question: I am being asked by patients and by parents in the community about my opinion regarding children wearing masks in school. I was wondering if the AAAAI has an opinion regarding this. Are there any updates on transmission of COVID-19 through children?

Answer: The AAAAI recently (in July 2020) released some general information supporting the use of masks to prevent the spread of COVID-19. 

Although children have lower risk for severe COVID-19 illness, they are clearly capable of transmitting the infection. Ongoing studies such as the Human Epidemiology and Response to SARS-CoV-2 (HEROS) study funded by NIAID will increase our understanding of the impact of COVID-19 in children and also the spread of this virus within families.

Current CDC guidance is for children 2 years of age and older to wear masks (cloth face coverings) when "in the community setting," which includes schools, to help prevent the spread of COVID-19.

Question: Are primary care doctors waiting too long to treat COVID-19? The interleukin system is bypassed so the body uses the T helper type 2 (Th2) pathway cytokine storm which looks a lot like asthma. Fatal asthma has the eosinophil kill the lung tissue. Once the lung is destroyed, our treatments don't work well. Would Medrol with antivirals stop lung damage progression? Is respiratory distress a too late marker to start treatment? Most medical trials start late (lung damaged already) to see if a treatment works. Hydroxychloroquine late wouldn't help, early it might but studies start it late. There are some reports of early Pulmicort working? I'm concerned that immunology isn't playing an early enough role in this disease. All I have read about the virus suggests promotion of Th2 pathway damage. Untested treatments are usually used on critically ill patients. Shouldn’t we be trying to prevent patient from reaching the critically ill stage? If so, how do we get it evaluated and get the message out? There is also some suggested long-term risk with COVID-19 vaccines, so could COVID-19 also have long term risks (provoking cytokine storm on re-exposure to the organism?

Answer:  Systemic steroids were shown to increase viral shedding in SARS, and by extension are presumed to do the same for SARS-CoV-2, although this is not yet verified. However, steroids late – at the time of the cytokine storm – do seem to have some efficacy, in some unpublished data.  This would mean that the use of steroids needs to be judicious and (ideally) based on biomarkers to determine who is most at risk of developing cytokine storm. At this time, we don’t have these biomarkers, and that is why treatment is started as the patient begins to do worse. Antivirials probably would be very helpful, but at this time there are no publicly available studies looking at steroids plus antivirals. Hopefully, over time such studies would be undertaken. Regarding Pulmicort, there are a couple of studies currently ongoing looking at budesonide or budesonide/formoterol as potential treatment (NCT04331054; NCT04416399; and NCT04355637).

The cytokine storm is more of an inflammasome/PRR related response (IL1b, IL6, CCL2, IFNg, TNF, etc.) as opposed to a Th2 type response (see

As far as risk of severe disease with infection in those vaccinated, this may be a real concern (similar to what is seen with Dengue, for example). Only clinical studies with significant numbers of subjects will be able to answer this question.

Question: The Task Force considers food and drug challenges medium risk due to (1) the prolonged office stay required for the challenge, and (2) the additional risk for a reaction (e.g., wheezing, cough, vomiting) that could produce aerosolized particles potentially infected with COVID-19, resulting in a higher likelihood of staff exposure and office contamination.

Is there a recommendation or protocol in place for potential allergic reaction and PPE during challenges?? As we move forward in my Allergy office with food and drug challenges, I would like to be prepared and proactive so that if a patient needs me urgently, I will have the proper PPE and protocols in place. Are they recommending to be in PPE during challenges or recommend to put on PPE when an allergic reaction occurs (which could postpone treatment time)?  I am set up to have 3-4 challenges a day. 

Answer: Depending on the situation, these challenges could also be high risk.  If the likelihood of a systemic reaction is high, then the risk is high.  The Task Force is not making any definite recommendations other that this might be a high risk procedure, since we don't have a reliable and readily available method to ensure that our patients are not infected.  PPE recommended for potential high risk contact include gown, gloves, N95 mask or equivalent, goggles or face shield.  This remains a fluid situation, what you do depends on the community spread in your area, the capability of your practice with respect to physical distancing and the availability of enough PPE to protect your staff.  Ultimately, it is your decision on what procedures you will do in your office.

Question: I have been talking and researching the use of ultraviolet light to kill coronavirus. Not internally but to use in an exam room. I was wondering people’s thoughts about having a PFT room. We would have nurses in full PPE do ENo and PFT. Could we use a strong UV light to sterilize room with devices that take 15 minutes in between conducting PFTs?

Answer: While UV light has been used to disinfect surfaces inside hospitals from bacteria and viruses, and also face masks/N95 respirators, there are important caveats to consider. The proper UV wavelength is imperative. There are no current FDA approved devices for use in medical offices, and the efficacy of this approach relies entirely on the light shining on every surface for sufficient periods of time. Machines, equipment, tubing, and connectors would require dedicated efforts to ensure the UV light was directed at all exposed areas for sufficient time. There are no current data or recommendations from the CDC or other governing bodies regarding use of UV light on spirometry machines or for purposes of rapidly turning over exam rooms in between individual patients. Of note, the CDC does NOT recommend for or against using UV light for CPAP machines but discusses risks associated with potential for the UV light to insufficiently penetrate to all surfaces, tubing, and connectors, in addition to risk from repeated or prolonged exposure to skin or eyes. The CDC also warns against claims being made by companies or products regarding their devices, as none currently have FDA approval or regulatory oversight, and the efficacy of each would rely on manufacturer data. As such, the Task Force is unable to offer any recommendation on using UV light for the purposes described in this question. 

Question: We have had a request to treat 'haemophagocytic syndrome' associated with COVID-19 with IVIG at a dose of 1G/Kg. What is your experience/evidence on how to deal with this? I have concerns about potential risk of this including how to deal with A/VTE risk.

Answer: The role of IVIG in this setting is certainly not established, but it has been used in other virally-triggered HLH settings. One expert provides that her ICU has also added either steroids or tocilizumab (if the IL-6 is high). If the patient is negative for virus by PCR (the post-infectious inflammatory syndrome) then steroids and perhaps a JAK inhibitor are used.

Question: I would like clarification on the attestation for the stimulus payment: Does "gross receipts" refer to the total income of the practice (all insurances) or only Medicare receipts? the amount may vary a lot depending on which is used.

Answer: The notice from CMS states gross revenue for 2018, not gross Medicare revenue.

Question: As we enter this next phase, understanding spread will be paramount. As allergists/immunologists we need to lead the charge in educating patients about what antibody testing is and most importantly, its limitations. 

It is helpful for the COVID-19 Task Force to assemble as much information about the sensitivity and specificity of the available and emerging antibody tests, along with any information about whether the antibodies detected actually confer immunity, in animal models. For those of us with more educated patients, it would be useful to put some of the immunology in perspective; everyone has heard of and remembers H1N1, so patients are interested in a brief description of the hemagglutinin and neuraminidase proteins on influenza in the context of vaccines and immunity, and how it applies to the coronaviruses.  What is the current understanding of the surface proteins and immunology of coronaviruses other than the obvious - antibodies we are making to the previously extant human coronaviruses obviously do not confer immunity to SARS-CoV-2 – including how these antibodies might interfere with the emerging antibody tests, and are the tests sufficiently specific so that previous coronavirus antibodies aren’t inflating the positive results (false positives)?

Answer: The Task Force is watching for more information about the validity of serological testing, although there are limited data. For the FDA’s data on sensitivity and specificity of the antibody tests that they have granted emergency use authorization for, please visit . We encourage everyone to continue to review the exploding literature on this subject, as we cannot publish such a list and keep it up to date sufficiently to continually provide the full body of information available.

Question: Can you comment on the KN95, non-American masks, as the CDC has commented that these are acceptable to use? The KN95 also has its own certification of whether it’s industrial or medical grade, but how do we know its level of protection against COVID 19?

Answer: During the current public health emergency, the FDA has listed acceptable substitutes for N95 masks, which include KN95 made in other countries with requirements similar to NIOSH.  You do need to be concerned about fakes as noted in our recent message, so if the KN95 has not been given an EUA, make sure that the FDA recommendations are followed.

Question: One of my medical assistants is asymptomatic, but was exposed to her mother-in-law who was COVID19 positive and admitted to the Hospital. She had herself tested and was positive. She claims no one else is sick in the house. We closed the office (no one else is sick) for ten days and reopened. 

When can she return to work, assuming she remains asymptomatic and knowing that she lives in the same house as her mother in law?

Answer: The CDC website details two strategies for determining when an infected health care worker can return:

  • Time based strategy. Exclude from work until 10 days have passed since the date of their first positive COVID-19 diagnostic test assuming they have not subsequently developed symptoms since their positive test. If they develop symptoms, then the symptom-based test or test-based strategy should be used. Because symptoms cannot be used to gauge where these individuals are in the course of their illness, it is possible that the duration of viral shedding could be longer or shorter than 10 days after their first positive test.
  • Test based strategy. Exclude from work until negative results of an FDA Emergency Use Authorized COVID-19 molecular assay for detection of SARS-CoV-2 RNA from at least two consecutive respiratory specimens collected >= 24 hours apart (total of two negative specimens). Because of the absence of symptoms, it is not possible to gauge where these individuals are in the course of their illness. There have been reports of prolonged detection of RNA without direct correlation to viral culture.

Additionally, once your medical assistant returns to work, require her to wear a mask until totally symptom-free or return to baseline.

Question: Thank you for providing the document outlining guidance on how to resume practices when regionally appropriate. I wanted to get more insight on why food/drug challenges are considered medium risk rather than low risk. Is it because of the time being spent in the office?

Additionally, what is the rationale behind skin testing in young children being considered medium risk rather low risk, as is the case in older individuals. Is it because young children have a greater likelihood of crying and spreading secretions while not wearing a mask?

I understand and appreciate there are no well-designed studies guiding these distinctions, but I was hoping to get a better understanding of the reasoning behind these two designations.

Answer: The Task Force considers food and drug challenges medium risk due to (1) the prolonged office stay required for the challenge, and (2) the additional risk for a reaction (e.g., wheezing, cough, vomiting) that could produce aerosolized particles potentially infected with COVID-19, resulting in a higher likelihood of staff exposure and office contamination. You are correct that young children are considered medium risk due to the greater likelihood of crying and spreading infected aerosolized particles.

Question: Do you have any experience with COVID-19 and indolent systemic mastocytosis marrow proven tryptase stable at 50 using cromolyn, H1/H2 blockers and ketotifen for flares? Patient is MD and worried about risk of exposures in practice and in particular risk of cytokine storm. 

Answer: The following was provided by a mastocytosis expert: 

There is limited experience with indolent systemic mastocytosis and COVID-19 infections. At our Mastocytosis Center we had two patients with tryptase of 150 ng/ml and bone marrow aggregates and positive KIT D816V mutation confirming the WHO criteria who presented mild to moderate cases. One woman who was not hospitalized and had the classical presentation with fever, dry cough and shortness of breath for 7 days duration, and a male with a moderate presentation with desaturation in the 80 percentage range, with a short hospitalization and no intubation and who is back home in good health. He required supplemental oxygen for few days. Both patients continued mast cell controller medications throughout the infection and did not present any cytokine storm-like reactions. The male who required hospitalization was treated with steroids and neither had a mast cell activation episode or anaphylaxis during the infection. Mast cells have been shown by single cell RNA analysis to have ACE2 receptors which is the required attachment site of SARS-CoV-2 and therefore can become infected (reference below). Whether mutated mast cells with KIT D816V mutation have increased or decreased ACE2 receptor expression is not known. Based on this limited experience, patients with indolent systemic mastocytosis are not at risk for more severe presentations of COVID-19 infection and should remain on mast cell controller medications throughout the infection.

Xu H, Zhong L, Deng J, et al. High expression of ACE2 receptor of 2019-nCoV on the epithelial cells of oral mucosa. Int J Oral Sci. 2020;12(1):8. Published 2020 Feb 24. doi:10.1038/s41368-020-0074-x

Question: Can we begin to apply skin tests utilizing the multi test device if the staff wears gloves and the patient wipes off his or her own skin tests, which are then read by the physician via telemedicine?

Answer: Staff safety is an obvious concern. Appropriate PPE for an extended encounter must be used. Screening for symptoms and contacts are helpful but not foolproof. There must also be the ability to treat any reaction (up to and including anaphylaxis) from skin testing.

For Medicare patients, if this is being applied by a staffer with a physician reviewing via telemedicine, waivers on telehealth apply to E/M encounters from a billing standpoint. Skin testing has a work component to the RVU which requires the physician read the skin tests. For patients covered by any other payer, the individual needs to check with the insurance carrier to see if 95004 would be covered for telehealth supervision.

Question: Despite preventative measures, the receptionist developed a fever of 102.9 with GI symptoms and headache with malaise, with negative Flu and Strep tests. COVID-19 test results are pending. Should the results be positive, in addition to totally shutting down the office, when is the best timing to test office staff to determine if any others are infected?

Answer: Please refer to the CDC webpage that discusses steps to take with potential exposure at work and in healthcare settings:

According to the CDC guidelines, all office staff in close contact with the case should be placed in self-quarantine to monitor symptoms. If you can test the remaining staff, the timing is tricky.  We know that most patients will develop symptoms between 5 and 12 days after exposure if infected, and the viral burden is highest in the day or so before and first few days of infection. Testing could be done after a couple of days. Testing too soon may result in false negative results.

Question: I was hoping to ask a few questions regarding the HHS Stimulus check I received. Reporting is required for those receiving funds in excess of $150,000.   I received a $25,000 stimulus check.  I will likely be receiving $300,000 in PPP loan funds plus a $10,000 EIDL Loan, so I will be subject to the reporting requirements.  I am planning to use the PPP loan for staff salaries, health insurance, rent and utilities.  What can I use the 25k stimulus check for?  Would using it for EMR maintenance fees and PPE purchases be allowable?  Can I use it for other things like our website support, or Zocdoc payments? What about other supplies?  Can I pull forward payments so I have $25,000 off expenses? Any information you can provide would be great.

Answer: The April 16th Task Force message answers some of the questions and also contains a link for further information. 

Here is an update from Hart Health, the AAAAI's consultants on legislative and regulatory affairs: The CARES Act Provider Relief Fund Payment Attestation Portal is now open. Providers who have been allocated a payment from the initial $30 billion general distribution must sign an attestation confirming receipt of the funds and agree to the terms and conditions within 30 days of payment. The portal has a variety of steps, including confirmation of eligibility, billing TINs, verifying payment information, attestations (likely related to the Terms and Conditions), and confirmation.

As a reminder, the Department of Health and Human Services (HHS) disbursement of this initial tranche of funds is conditioned upon the healthcare provider's acceptance of the Terms and Conditions, which must occur within 30 days of receipt of payment. Not returning the payment within 30 days of receipt will be viewed as acceptance of the Terms and Conditions. The provider must do the following: contact HHS within 30 days of receipt of payment and then remit the full payment to HHS as instructed. The CARES Act Provider Relief Fund Payment Attestation Portal will guide providers through the attestation process to accept or reject the funds.

Question: In some of the COVID-19 convalescent serum studies, they are transfusing two units of plasma while in other studies they are using one unit. If we use two units it may be more effective, but one unit would enable us to treat more patients. Do you have any advice on which would be preferred?

Answer: In an open label study with a treatment cohort of 10 patients in China, Duan K, et al. (1) administered one dose of 200 mL of convalescent plasma derived from recently recovered donors with the neutralizing antibody titers above 1:640 as an addition to maximal supportive care and antiviral agents. The authors concluded that one dose of CP with a high concentration of neutralizing antibodies can rapidly reduce the viral load and tends to improve clinical outcomes. The optimal dose and treatment time point, as well as the definite clinical benefits of CP therapy, need to be further investigated in randomized clinical studies.

As more studies are done and made available, clearer standards will be established. For now, there is evidence that a single 200 mL of convalescent plasma with the neutralizing antibody titers above 1:640 is effective.

It is not possible to make any real recommendations on therapy at this time. Larger, controlled studies are needed to determine the efficacy of therapies for COVID-19.

Please note the AAAAI is not endorsing any therapies at this point.

1) Duan K, Liu B, Li C, et al. Effectiveness of convalescent plasma therapy in severe COVID-19 patients [published online ahead of print, 2020 Apr 6]. Proc Natl Acad Sci U S A. 2020;202004168. doi:10.1073/pnas.2004168117

Question: Should we continue patients on swallowed corticosteroids treatment for EoE patients during the COVID19 pandemic?

Answer: Consistent with previous recommendations concerning the use of inhaled steroids, nasal steroids, and systemic steroids for asthma exacerbations, while there is a lack of relevant data, continuing use of swallowed steroids seems appropriate for this population. The American College of Gastroenterology has issued some guidance for patients with IBD: "Being on immune therapies for IBD may increase the risk for some infections, but the currently available information does not show an increased risk of infection with SARS-CoV-2 or development of COVID-19 in individuals with IBD or who are on the standard therapies."  The CDC has indicated approval for continued use of steroids for indications other than COVID-19.

Question: We are still giving allergy shots in my office, utilizing available PPE: wearing goggles, slightly expired N 95 masks, and gloves. We are also wearing lab coats and washing daily.

We have been using a Welch Allyn digital thermometer to take temperatures of all shots patients prior to giving them injections. Our office had recently ordered a supply of surgical masks. In light of the recent CDC recommendations to skip taking temperatures on all patients, should we give each a surgical mask when they walk in the office for shots? What is the best practice to protect nurses working with these patients?

Answer: All patients should be considered potentially infected regardless of the absence of symptoms. The reason for masking patients and others is not to protect them from catching an infection, but to prevent asymptomatic people from infecting others. Screening for symptoms and signs is important but not sufficient.  All patients should be masked. Patients with symptoms or signs should be considered for exclusion from the office because the likelihood of infection in those patients is much higher, as is their potential to spread infection to others.  It is important to continue to practice physical distancing and hand hygiene for all.

Question: I just had a patient come in with flu symptoms, but could it be COVID-19? What do you recommend for possible exposures?

Answer: This is very much an evolving space. The response depends in part on the level of community spread going on in your location. If you are in an area without community spread, then you need to assess for other risk factors—especially, in the 14 days before the onset of symptoms did the patient have a history of travel on an airplane, a cruise, or any travel to/from New York City or close contact with someone who has laboratory confirmed COVID-19. If the answer to either of these questions are ‘yes’, then the patient should be screened for COVID-19. In an area with community spread, the above questions become less helpful. In that case, it certainly could be COVID-19 (although it could also be the flu, although the flu activity is markedly decreasing as of the end of March). Unfortunately, there really aren’t any good discriminators between COVID-19 and influenza symptoms (at least at this time).

For possible exposures, refer to the CDC website. This website has a good risk assessment tool that provides guidance for healthcare workers who have had differing levels of potential exposure to a COVID-19 patient.

Question: Regarding COVID-19 and the use of a nebulizer in a clinic setting and the risk for spreading of the virus, are there institutional guidelines for use of a nebulizer? Given the data of suggested transmission in the in-patient setting, should we eliminate use of the nebulizer in the clinic? (And not just in an A/I division, but a pulmonary lab where they use for PFTs, family practice, internal medicine, pediatrics, UCC, etc.)

Answer: The CDC considers the use of a nebulizer as a procedure that can generate aerosols that contain respiratory secretions. Therefore, for a patient with COVID-19 the CDC recommends the healthcare worker wear a full PPE (gown, gloves, eye protection, and a respirator—note a PPAR or N95 respirator is much better than just a facemask*) when having close contact with the patient while they are getting a nebulization. This is for a known COVID-19 patient. There are no clear guidelines for suspected or unknown COVID-19 patients. However, given the issue of asymptomatic viral shedding and the likelihood of community spread, it is prudent to act as though all patients were infected with SARS-CoV-2 and wear full PPE as mentioned above, if nebulized medication is needed. It would be far better to use an MDI mediated therapy, if at all possible (in that case there is no evidence of viral aerosolization).

*The CDC considers it high-risk to be exposed to a COVID-19 patient getting nebulizer therapy with no PPE; however, the use of all PPE with a facemask but no respirator only reduces the risk to medium level (not low). It is important to use a respirator (N95 or PPAR) if at all possible.

Question: Our location is in an acute essential ambulatory setting both for Internal Medicine and Allergy/Immunology. Should we be performing PFT/Bronchospasm Evaluation in this setting for non-COVID19 patients? We are in New York, where everyone with similar symptoms is treated as being COVID19 positive until proven otherwise, but at the start of the Spring allergy season.

Answer: Although most spirometers and Niox devices have filters, it is not known how effective they are in reducing droplet spread of SARS-CoV2 virus particles.  Currently these procedures, along with nebulization, are considered aerosol generating procedures and are best performed in a negative pressure room by someone with complete PPE for aerosol generating procedures.  This would pretty much rule out doing these tests in the office, since it appears we can’t always rely on symptoms to rule out infection.  One suggested approach would be to dispense a peak flow meter for your patient to use at home, and have them monitor baseline peak flows and response to medications.  While this is not generally the best approach, it is the safest at this point.

Question: What is a practicing Allergist to do in this pandemic? Masks are not available. Telemedicine does not seem feasible. More importantly, when will the serologic tests be available? It seems to me that cases are increasing, mainly because the testing is ramping up as well. For example, NYC has lots of challenges based on population density, but they are currently also doing the most testing.

Correct me if I am wrong, but because there are also so many asymptomatic patients, it would seem that only those who have had the infection and have adequate antibodies would be safe. I am not even sure that is true. How long does it take to develop antibody titers that would be protective? Is it two weeks like influenza, or longer? Will the testing be like EBV and be able to give an IgM vs. IgG response?

Answer:  Your frustration is understandable. Availability of PPE continues to be a problem, and that is why some allergy practices have chosen to only see sick patients by telemedicine and screen patients before their appointment as to current symptoms and exposures, although that does not guarantee absence from exposure.  Some practices have converted all patient encounters to telemedicine. The federal government and many states have issued waivers to make telemedicine much more possible for the practicing allergist. Reimbursements are improving and in some cases (Medicare) are equal to in-person visits. Others are following suit.  The AAAAI has provided and continues to update telemedicine resources, both specific to COVID-19 and the Telemedicine Toolkit. There are also waivers in place to use Skype or Facetime with Medicare patients, if that is all that is available, during the pandemic.

It appears that there are currently two serological test kits available for measuring IgM and IgG responses to SARS-CoV2.  The first is a test kit that reportedly has been launched via direct-to-consumer marketing for in-home use.  It is done with a drop of blood, and is called CoronaCheck, by 20/20 Bioresponse and the company announced on 3/19/2020 that it will begin taking orders. The second lab test is produced for CLIA-certified labs by Diazyme and has been approved under the FDA EUA procedure.  It may not be available everywhere, since it has to be run on proprietary equipment also marketed by Diazyme.  This is a chemiluminescent assay. The AAAAI does not endorse any specific commercial products for this or any other purpose.

It is not known at this time how helpful these and other tests will be for diagnosing an acute infection, compared to the PCR test, but they may help track patients who have been infected.

There are many patients who have become infected without a known exposure. Whether this is due to viral shedding from an asymptomatic patient, or infection from fomites on surfaces, is not known.  The main risk for infection is by droplet spread, so avoiding contact with droplets (PPE or social distancing), hand hygiene and frequent office cleaning makes sense.  We don’t know how long immunity lasts after the infection, but certainly hope it is long lasting, so this does not recur frequently.

In a podcast with Dr. Mitch Grayson, a member of the Task Force, your question about the immune response to SARS-CoV2 virus is discussed. In a study from China and Yale University, IgM and IgA against SARS-CoV-2 was seen in 5 (3-6) days after symptom onset (median (IQR)), while IgG was seen 14 (10-18) days post symptom onset. So, the answer is yes, there is both an IgM and IgG response, with the M being the more acute.

Question: I would like to know if there is any data on regarding COVID19 and the flu shot, and specifically whether there is concern about “virus interference.”

Answer: There is no data on interference and nothing in the public health recommendations even hint at that. Although the flu vaccine for the northern hemisphere was not very effective this year, it did appear to lessen the severity of the flu in those that were infected, even though it did not prevent the flu. At this point the important thing is to keep people out of the emergency department and the hospital so that resources can be conserved for the COVID-19 patients.  Where the flu is still spreading, based on the current knowledge and recommendations, patients should be immunized against influenza.


Some answers have been updated to reflect changing circumstances and information since the individuals submitting the questions were originally provided with a response. While we’re working on keeping answers updated as best we can, information continues to evolve rapidly. Please email us at with concerns or additional questions.