These are outstanding questions answered by the SHEA COVID-19 Town Hall experts based on their expert opinion. Special thank you to Drs. Mary Hayden, Sarah Haessler and David Weber for their contributions.  Please scroll further down for answers from special guests of the SHEA Town Hall. 



Question: If a spouse of HCW had COVID-19, separated from the HCW, then a child a few days later developed infection and the spouse (recovering) now takes care of the child, can that spouse exit isolation after day 10, or does their isolation + quarantine (due to ill dependent child) change?  What would that time length be for the spouse be - 10 day isolation plus child's 10 day isolation (minus overlap)?  --- The question impacts workforce:  the quarantine for HCW does shift, but if the spouse cannot come out of isolation and quarantine to assist with the rest of the family - impacts the HCW return to work date re: family support and quarantine period.  Thanks for your thoughts.


Answer: Exposure period starts last day of exposure (based on infectivity of contact) – we test HCP at day 6-7 after last exposure, allowed to return to work at day 10 is still asymptomatic


Question: Do you stop transmission-based precautions in immunocompromised patients with a vent/trach who are more than 20 days from onset of symptoms, whose symptoms are improving, and who have not had fever for more than 24 hours?       


Answer: We still use a test-based strategy for very immunocompromised patients (CART, BMT e.g.) but for most patients we use time-based strategy as described in question.


Question: Is there any evidence that remaining partial vaccine doses combined from more than one unexpired vaccine vial could be harmful?  If not, a revision of guidance to allow this would recover some otherwise wasted vaccine volume.

Answer: Risk of combining product from multiple vaccine vials is from the no preservative in vials – 6 hour shelf life after reconstitution – risk is vial contamination with subsequent infection.


Question: Could our faculty comment on the letter in CID from Drs. Plotkin & Halsey endorsing expanding vaccine usage and delaying the second dose (based upon experience with memory response from other vaccines).

Answer: Short-term delay (up to 6 weeks ok) – but 1 dose of mRNA vaccine only ~50% effective; durability of vaccine response unknown with single dose


Question: Can you please comment on the use of aspirin prophylaxis before COVID vaccine? Aspirin is not mentioned on CDC Website.            

Answer: Aspirin has anti-inflammatory effects and so I would think that the same theoretical concerns around NSAIDS apply to aspirin.


Question: What about masking over N95 respirators? I see that a lot. More is better and protecting the N95.

Answer: Double masking is a method of improving the fit of procedural masks. N95 respirators are fit tested so that they fit tightly to the face. Adding a second mask would therefore not improve the fit of the N95 respirator. Wearing a procedural mask over an N95 mask to extend the use of the N95 could be considered as a crisis strategy when N95 respirators are in short supply. Wearing a cleanable face shield over the N95 is preferred, though, as a means of protecting the respirator.


Question: We are seeing lots of CLABSI and CAUTI especially in COVID patients along with C. auris. Any comments?

Answer:  At our acute care hospital in Chicago, we have not seen an increase in C. auris infections, despite significant C. auris endemicity in area long term care facilities.


Answers below provided by our special guest, Mitchell J. Schwaber, MD, MSc.

Question: Have you had breakthrough cases? Related to variants or other pre-disposing conditions?

Answer: There have been documented cases of infection despite full vaccination (full vaccination = 2 doses of Pfizer vaccine + 7 days).  Some of these have been asymptomatic - detected due to institutional screening programs, but others have been symptomatic.  This is not unexpected, as the vaccine is not 100% effective at preventing illness, and we still don't know what its effectiveness is in preventing asymptomatic transmission.  Don't have data as yet as to whether and to what extent pre-disposing conditions enhance the risk of post-vaccination infection, but having a pre-disposing condition is clearly not a prerequisite.  Estimated that over 90% of circulating virus in Israel at present is B.1.1.7, so presumably most if not all cases of infection occurring now – among vaccinated and unvaccinated – is with this strain.

Don't have solid data as yet about risk of secondary infection from a vaccinated source.  Anecdotally, I believe there is reason for optimism on this point, and that optimism is further supported by one of the papers Dr. Weber presented  at the Town Hall (, demonstrating reduction in viral load in those infected as of 12 days after the first dose of vaccine.  It would make sense that risk of secondary infection would be a function also of vaccination status among those exposed.

As to management – once confirmed SARS-CoV-2 positive, isolation requirements and contact tracing are identical for vaccinated as for unvaccinated.  Two caveats here – 1. A vaccinated contact does not need to quarantine as long as asymptomatic; 2. Due to concern about false-positives in populations with low pre-test probability of infection, in ongoing institutional routine staff screening programs among elderly and other care facilities, two consecutive PCR-positive swabs are required to diagnose infection if the screened asymptomatic staff member is fully vaccinated; and if contact tracing due to a positive result generates testing among asymptomatic vaccinated residents, they should be double-swabbed and considered infected only if both swabs are positive.


Question: Does the green card for vaccination expire after a certain time?

Answer: At present it is valid for 6 months.  Duration of validity to be further evaluated with gathering data.


Question:  Is Israel vaccinating long COVID-19 patients?

Answer: Not per se.  We are offering vaccination (single dose) to all recovered patients 3 months after infection, and residents of elder and other long-term care facilities were vaccinated en masse with 2 doses, including those recovered from COVID-19.


Question: What is Israel data on post vaccine reaction/complications?

Answer: Being gathered by MOH.  To the best of my knowledge, in line with data assembled worldwide, i.e., most reactions mild and transient.  Following reports of post-vaccination myocarditis, pericarditis and multisystem inflammatory syndrome in adults, data presently being gathered to determine whether related to the vaccine. 


Question: Any COVID19 lessons in preparation for the next influenza season in Israel?

Answer: For the first time in (at least my) memory, the current influenza season in Israeli has been essentially non-existent.  To the extent that this is related to human behavior (masking, distancing, crowd avoidance, reduced travel, etc), I suspect that we may not see such low numbers repeated next winter.  Hopefully, some of the healthy habits taken from pandemic-related behavior (for example, staying home when sick) will persist in a post-pandemic reality.


Question:  Could Dr. Schwaber comment on changes, if any, to preprocedural testing in vaccines.

Answer: This is determined at the local hospital, rather than the national, level.


Question: Any severe reactions in persons who have recovered from COVID and received 2 doses of vaccines?

Answer: None that I am aware of.  Most of those recovered will not receive 2 doses of vaccine, as they were initially not vaccinated and at present are offered a single dose if 3 months have passed since infection.  However, as noted, residents of elder and other long-term care facilities were vaccinated en masse with 2 doses, including those recovered from COVID-19.  I am unaware of reports of severe reactions among those recovered.


Question: Is there any clinico-epidemiologic basis for preference for mRNA vaccines for residents of skilled nursing and assisted living facilities Dr. Schwaber should Janssen vaccine be available in Israel?

Answer:   Not sure, but at present the question is largely moot in Israel as the overwhelming majority of residents of skilled nursing and assisted living facilities have been vaccinated with the Pfizer vaccine, with excellent results, and the Janssen vaccine is not currently available here.  Should it become available here in the future, and another round of vaccination be warranted, the question may be on the table.


Question: Do you think we will have definitive evidence about effectiveness against asymptomatic spread before the end of the year?

Answer: "Definitive" is a relative term with this virus, but I do expect that by year's end we'll have a lot more data than we do at present regarding vaccine effectiveness against asymptomatic spread.