April 24, 2020


SARS2 virus continues to show us that it is the cause of much morbidity and mortality in a select group that gets infected. However, as initial data sets appeared in Italy, Spain and subsequently NYC with dire risks and awful CFR's, case fatality rates, we now see that this is unlikely to be the true reality or the IFR, infected fatality rate. Let us continue our dispassionate tour through the data as we finally have some reasonable domestic data to peruse.

 The biggest data sets in the United States come from Los Angeles county and New York City. The LA County data was published in the Los Angeles Times and other news media sites. From the LAT article: "The initial results from the first large-scale study tracking the spread of the coronavirus in the county found that 4.1% of adults have antibodies to the virus in their blood, an indication of past exposure. That translates to roughly 221,000 to 442,000 adults who have recovered from an infection, once margin of error is taken into account, according to the researchers conducting the study. The county had reported fewer than 8,000 cases at that time." (Mason M. 2020)

Let us run these numbers. Currently, there have been 617 deaths in LA county as of 4/20/20. By early April, 221,000 adults in LA had been infected and recovered, that is an IFR of 0.28%. If this number is more in line with 442,000 adults as the study estimates, then the IFR is 0.14%. This is just like the seasonal flu and far less deadly than projected by many models. Modeling, or thoughtful statistical predicting, is generally a total mess in pandemics as Dr. Peter Attia aptly points out in his most recent email that you can read HERE . If this infection rate is true and likely is based on multiple sources now, than there has been over 69,000,000 infected and recovered humans worldwide, 174,000 deaths and an IFR of less than 0.2%.

The New York City data set was published in the New York Times and CNBC noted a 21% immunity rate in NYC. From the CNBC article: "An estimated 13.9% of the New Yorkers have likely had Covid-19, according to preliminary results of coronavirus antibody testing. The state randomly tested 3,000 people at grocery stores and shopping locations across 19 counties in 40 localities to see if they had the antibodies to fight the coronavirus, indicating they have had the virus and recovered from it... With more than 19.4 million people residents, according to U.S. Census data, the preliminary results indicate that at least 2.7 million New Yorkers have been infected with Covid-19. The results differed across the state with the largest concentration of positive antibody tests found in New York City at 21.2%. In Long Island, 16.7% of the people tested were positive and in Westchester, where the state's first major outbreak originated, 11.7% of the tests were positive. The Covid-19 pandemic across the rest of the state is relatively contained with just 3.6% of positive test results." (CNBC Article)

Looking at these numbers, NYC has 19,400,000 residents, 2,700,000 presumed immune (21%) and 15,074 deaths confirmed as of this writing. Therefore if we assume 60% immunity is needed for herd immunity, that would be 3x the death total to date or roughly 45,000 individuals. Thus, NYC statistics show that the IFR is 0.21% or twice as deadly as the seasonal influenza virus. It is 3-4 times more contagious then the annual flu and we have no apriori immunity meaning that there will be more overall deaths comparatively.
These are straight numbers as they exist today. They are very reassuring. I say this with all deference to the infected and the deceased. Again, this is a dispassionate analysis. The European experience was and is clearly different than the majority of the US experience likely based on an advancing age population, which increases chronic disease incidence and death rates, and a huge viral exposure event in Lombardy, Italy and other locations that began in Wuhan, China that overwhelmed the medical system.

There is also some chatter coming out of Santa Clara, California regarding the first known US case of COVID that occurred on February 6th. This means that the infection likely was in the United States by early January as the infection precedes death by 3-4 weeks at the same time as China was starting to wake up to the knowledge that this virus was spreading. This would also reinforce the fact that community spread was long occurring before we became aware and that the number of immune Americans is likely much higher than previously believed as the LA county and NYC data shows.


We stand at the crossroads of choice based on the newest data that leads us to a place vastly different than from 4 weeks ago as witnessed by protests and impending differential state government decisions regarding COVID safety rules. Choice one is to stay the course of aggressive lockdown behavior and business closure and risk further economic damage that has it's own immensely dangerous social effects, poverty induced disease. Or, choice two is to begin rational loosening of the restrictions with massive testing to finally begin the quarantine event targeted to the exposed, ill and at risk as the epidemiologists have discussed.

In my opinion, the answer to this choice is going to have to be state and municipality based. New York City and Jackson, Wyoming are going to and should have completely different viewpoints to this issue as their risks are vastly different based on population numbers and demographics of disease burden. That being said, fear is driving too many decisions where prudent prevention and testing should be the story of the day. If the LA county and NYC experiences are correct, we are much farther down the road to herd immunity than expected.

We also need to continue to be very aware that there are significant consequences to non COVID patients in this current era as people are afraid to enter the medical system at all and this in and of itself is a major risk if you are suffering from a heart attack or other acutely risky disease. Read this piece from the New England Journal of Medicine.

We need to be aware that people are afraid to loosen the restrictions. I have heard from many folks recently that this change is unsettling as the fear of COVID is still profound for many. I feel that it is very important to honor their fear while dispassionately discussing the true risk as it exists today. It is best for all of us to be non judgmental regarding everyone's individual choices whether to wear a mask in public, whether to continue to stay home, whether to travel and move towards a normal life within the framework of each municipalities expressed rules.

I reiterate from last week, until we know which path to be true, we as a society will need to continue to be smart about our actions. Reducing direct contact, i.e. handshakes and hugs, will need to be the norm for a while. Self quarantining pending a COVID test result will be necessary. Avoiding high risk individuals in general is a great idea. Individuals over 60 years of age and people with cancer, hypertension, diabetes, obesity and other risk factors need to seriously consider staying quarantined for a while as it is hitting these groups hard.

 Most importantly, we need to continue to follow the directives of the individuals with the most knowledge, the CDC.

 It is just data sprinkled with some opinion,

Dr. M

 SARS2 Severe adult respiratory syndrome coronavirus is the viral name

COVID 19 is the disease name

Los Angeles Times Article
New York Times Article
Peter Attia MD
Rosenbaum NEJM Article
Hopkins Home Site for COVID Cases
CNBC Article
New York Times Article 2