September 23, 2020

Are There Covid-19 Reinfections?

Within the last weeks Covid-19 reinfections were reported in 4 patients, separated in time from their first episode.  Sometimes patients continue to have a positive molecular virus test after their Covid-19 infection, but the PCR test is able to measure remaining dead virus after recovery. RNA viruses mutate slowly, usually in unimportant portions of the virus.  The ability to sequence the RNA allows scientists to detect mutations - and that is how they determined that NYC was infected with a European strain of SARS-CoV-2, not the Wuhan strain.  The European strain was infecting communities in NYC long before there was any control of the planes arriving from Europe or even China. 

I was surprised that in the 4 patients with recurrent disease (one each from China, Belgium, Netherlands, and Nevada), scientists were able to compare the SARS-CoV-2 virus that was isolated from both their first and second positive SARS-CoV-2 virus samples.  There were different mutations present when the rwo samples were compared, thus demonstrating that these were 2 separate infections in each patient.  It is not clear how many cases of reinfection will be reported, virus samples from each episode must be available for testing.  These cases were each reported online, not in published scientific papers that I could find. 


September 19, 2020

What is a Covid-19 "Long Hauler?"

These are patients who have continuing symptoms for 4 or more weeks after Covid-19.  Symptoms can last more than 4 weeks after mild cases of Covid-19, and more than 8 weeks after hospitalized cases.  Unfortunately symptoms can last for months.  Many of the current long haul patients couldn't get a virus test when they first became ill because of the restrictions on testing.  But many of them now have positive antibody tests documenting the virus. 

Symptoms are very variable among patients, and in general they haven't returned to their pre-infection status.  There are respiratory symptoms, cardiac symptoms, decreased taste/smell, myalgias, headache, sleep problems, clotting disturbances, skin rashes, foggy brain, and fatigue mirroring chronic fatigue syndrome.  Although there are theories about the cause including continued infection or immune response to the virus and/or virus debris, the cause is unknown.  The incidence is greater than has been seen with other viral infections, and specialized centers are being developed to assess these patients and test therapies.  Long hauler patients are advised to locate one of these centers.


September 16, 2020

How Will We Drink Our Wine?

The Risks of Developing a Covid-19 Infection: From Morbidity and Mortality Weekly Review (CDC)

Just as New York City set a date to open indoor dining, the CDC released results from a study they did during the month of July on Covid-19 risks associated with various settings and exposures.  They found that restaurant eating and bar/coffee shop attendance had almost 2-3 times the risk for developing Covid-19, in comparison to many other activities.  The methods of the study were classic - a cohort of Covid+ patients from 11 trial sites were compared to a cohort of Covid-19 negative patients.  Everyone had to answer a battery of questions about their activities in the two weeks before their symptoms and virus tests.  Questions included mask wearing, and common activities: shopping, gym, salon, church/religious events, office work, and public transportation.  Only eating in restaurants, bars/coffee shops were statistically significantly associated with Covid-19 positive tests.  The lack of social distancing and mask use, while talking and eating, all contribute to the risk - outside or inside according to the data.



September 12, 2020

Vaccine Update - Halting One Trial

There are 3 vaccines that are in Phase 3 Trials in the US - each with a goal of enrolling 30,000 people - half to receive the vaccine and half to receive placebo.  They are vaccines from Moderna, Pfizer/BioNTech, and Oxford/ AstraZeneca.  No one will know what each person received until the end of the trial.  However there are independent Data and Safety Board Monitors and they can "unblind" the trial if there are problems. 

This week a person in the UK AstraZeneca trial developed a neurological problem and all of their trial sites were halted until the person can be fully evaluated to determine the cause.  They currently have trials in the UK, Brazil, South Africa and the US, although the trial in the US just started.  To date thousands of volunteers have received this vaccine in the UK.  In July they also briefly halted the trials and the volunteer was diagnosed with a previously unknown disease.  The safety considerations during vaccine development are paramount.  Yes, scientists want the vaccine to be efficacious, but safe.  Read more below.


Moderna and Pfizer have each enrolled about 20,000 healthy volunteers to date - each person gets 2 doses (21 days apart -Pfizer- or 28 days apart- Moderna).  Subjects are followed and tested regularly for safety and efficacy and the followup continues even after the vaccine is approved. 

Clinical Trial Approval Process that all vaccines, drugs, and medical devices must conduct to apply for FDA approval. 

Phase 1 trials are small (ex 50 volunteers) - to test different doses and assess safety.

Phase 2 trials have hundreds of volunteers and safety is still being assessed.  Vaccine effectiveness and antibody production is being measured in randomly assigned vaccine and placebo groups.

Phase 3 trials have thousands of healthy volunteers, randomly assigned to vaccine or placebo groups. Safety is still assessed, while effectiveness is measured.



September 9, 2020

College Students Return to Campus and Covid-19

There are now thousands of new Covid-19 cases on college campuses as students and staff return for the Fall semester (estimate 51,000 yesterday). Many schools have been forced to close down and send students back home.  Students were tested on arrival and additional means to control the virus are being tried.

The University of Arizona tried a technique that was used previously in polio epidemics in the 1930 to identify community outbreaks.  A small sample of pooled waste water from sewage is one of the first ways to detect the virus in a community, as the virus is shed very early from the GI tract.  Students were all negative when they arrived on campus, but during the waste water testing process one dorm was positive.  All of the 311 students were tested by molecular testing and 2 of the students were positive and could be isolated.  A recent update showed that a total of 46 students were now positive, among 10,000 antigen tests  Hopefully this is a manageable number for tracking and isolation and the campus can stay open. 


Other schools have set up twice weekly wastewater surveys, including Syracuse, Univ. of California San Diego, and Rensselaer Polytechnic Institute according to the press report  and can identify and quarantine positive students - keeping everyone on campus.  This is a good strategy for detecting small outbreaks and containing them on campus.  


September 5, 2020

Testing for Antibodies in Covid-19 Patients

There are many types of antibody tests available, each using one of 3 different methods.  They can measure 2 different types of antibodies:  Immunoglobulin M (IgM), which usually appears first, and /or Immunoglobulin G (IgG) which usually doesn't appear until after 2 weeks.  The Infectious Disease Society of America expert panel currently recommends testing sometime between the 3rd and 4th week after symptoms develop in patients in which this information is important.  It is most helpful in symptomatic patients whose SARS-CoV-2 virus test is negative. 

But these antibody tests are not routinely recommended for an individual patient, because the presence of antibodies doesn't mean that they are immune and may give a false sense of security.  These serologic tests are most useful when screening large populations of people in order to assess the prevalence of past infections by region. Continue Reading


I live in New York City and results of 1.5 million antibody tests were recently released from the Dept of Health.  Antibody tests for Covid-19 were positive in more than 27% of NYC residents, and the numbers varied by zip codes, and boroughs.  In one zipcode more than 50% of the antibody  tests were positive, demonstrating a high incidence of Covid-19 at some time during the Spring or Summer. 

September 2, 2020

Another Point of Care Covid-19 Antigen Test

Is it a game changer?  Maybe slightly.  Abbott's BivaxNOW Covid-19 Antigen Card is like a pregnancy test, takes only 15 minutes, and only costs $5.  A nasal swab sample is applied to a card and when the Sars-CoV-19-nucleoside antibody on the card detects the virus a pink line forms below the positive control line.  The square with the arrow on the card is where this happy patient's sample reads negative.

But the test, which does not require a machine to read the result, still needs to be performed in a doctors office, clinic, or other health care facility.  In addition the test has to be performed within 7 days of the onset of symptoms making this a diagnostic test, not a surveillance test for public health detection. 

Last week the FDA gave an Emergency Use Approval (EUA) based on only 102 samples tested.  The sensitivity and specificity which were excellent were thus determined on a very small patient group. The results are saved in a free app on the patient's phone and can provide an ongoing record of test results.  But will they be also be reported to the Dept. of Health?   This Abbott BivaxNOW test will now be scaled up this month - millions of the tests have been purchased by the US Government.   Continue Reading Below


Dr. Michael Mina an epidemiologist/scientist from Harvard, advocates for a simple public health test based on the same principle, i.e. like a home pregnancy test, but the FDA hasn't yet approved "at home tests." I've discussed the "Rapid At Home Test" previously, and I'm hoping that the Abbott approval may be an early indication that the "at home tests" may also soon be approved.  When it is available, it will allow people to do frequent tests on themselves and their family.  If they are infectious (and not symptomatic) they can stay home when the test is positive.  There is a good correlation between the period of viral shedding and the test turning positive within 1-2 days.  If this test is approved, it will be a better way to control the pandemic. 



August 26, 2020

Monoclonal Antibodies Enter Phase 3 Clinical Trials

At this time convalescent plasma is either a therapeutic "breakthrough" for Covid-19 or an unproven therapy to passively transfer antibodies from a recovered Covid-19 patient, because no randomized control trials were completed.  Thousands of patients have been given convalescent plasma and yet  Phase 3 randomized, placebo-controlled trials have not been done.  

Very specific monoclonal antibodies, which are directed against the spike protein of coronavirus, are now entering Phase 3 Clinical Trials, and hopefully these will be both effective, safe, and scientifically proven.    

Monoclonal Antibodies:

This technology was first developed in the 1970s and is now being used to create many types of therapy, including cancer "drugs".  In the classic method, cells from previously infected patients are fused with a antibody producing cells that are grown in cell cultures.  These cells become a protein factory which manufacture just one potent neutralizing antibody against the virus. They can then be infused into patients.

Several monoclonal antibody phase 3 trials were just started and everyone is hoping that these highly specific antibodies against SARS-CoV-2 will be able to prevent infection after a close contact.  Continue Reading: 


One of the monoclonal antibodies is from Lilly-NIAID (NIH) and contains one antibody to the spike protein that was made from blood of an early Covid-19 patient. They started enrolling patients on Aug 2nd and they plan to enroll 2400 subjects.  Subjects must be at high risk of infection either residing at, or working in a skilled nursing home or an assisted living facility. This is a randomized controlled study with half the patients receiving placebo.  It is also double blind meaning neither the patient, nor staff know what was administered.  Subjects will be followed up for 24 weeks.

The second monoclonal antibody, developed by Regeneron, is actually a "cocktail" of two antibodies which are directed against different places on the virus spike protein.  It too was manufactured from a recently infected Covid-19 patient. They plan to enroll 2000 asymptomatic adult patients who were exposed to a Covid-19 patient living at the same address.  The Phase 3 trial is randomized, placebo-controlled, and blinded to patient, staff, and oversight board so they won't know who received antibodies or placebo until the end of the study.  They will assess subjects for infection at 1 month and continue to follow them for 7 months for safety data.  They started enrolling patients on July 13th. 


Shirley Parker Levine
New York City

September 2020

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