NYC Passes the 25% Threshold While Anti-IL6 Results Confound

The latest COVID-19 figures from NYC are in and they are as impressive as the Skyline!

Governor Cuomo announced that 25% of NYC residents are positive on COVID antibody (blood) testing, while 15% of NY State residents are positive. This means that when the blood test was done, 25% of NYC residents and 15% of state residents had been infected with COVID-19.

These numbers are not surprising to readers of my blog, but the press in NYC didn’t get one of the implications.

All the blood samples were first collected, then transported and run through a laboratory in Albany. This suggests they were collected about a week ago. Also, antibody development (IgG) in response to the COVID infection requires approximately 15 days after the start of symptoms. If one then adds a few days from infection to symptom onset, that adds up to 25 days.

So, 25 days ago (the end of March) 25% of NYC residents were infected. Given the doubling rate of the infection, even with social distancing, this again suggests that 50% of NYC residents are or have been COVID-19 infected at the present time.

Don’t mean to harp on this but I think herd immunity is playing a role in the reductions in hospitalizations and deaths in NYC I presented yesterday.

Anti-IL6 Receptor antibodies Give Mixed Results.

Another interesting issue tonight was around the concept of anti-inflammatory (anti-arthritis) drugs being repurposed for COVID-19 treatment. It was thought that these drugs cold be beneficial by decreasing the inflammatory “cytokine storm.” A study in China showed no value for the anti-IL6 receptor drug from Regeneron/Sanofi (Kevzara). In fact, some patients actually did worse on the drug.

In contrast, another small study done in France with the Roche/Genentech anti-IL6 receptor drug Actemra did show benefit for cytokine storm. The latter study was not blinded, which may question the interpretation of the results.

While there are some differences between these drugs, such as the route of administration, this really leaves us in a quandary about the anti-inflammatory approach to treating COVID associated cytokine storm.

The most important lesson; no matter how attractive the rationale, blinded, controlled studies have to be done before any drug is widely used or recommended for COVID treatment.

Published by jbakerjrblog

Immunologist, former Army MD, former head of allergy and clinical immunology at University of Michigan, vaccine developer and opinionated guy.

One thought on “NYC Passes the 25% Threshold While Anti-IL6 Results Confound

  1. But, how reliable are the tests? Medical publications state many different producers, possibly many false positives and negatives, and no clarity if antibodies confer immunity or resistance


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