On April 4th I wrote my second blog about COVID-19. At that time we were 95 days out from the first mention by Chinese health care workers identifying an infectious novel coronavirus cluster. At the time, there were documented 1,192,028 global cases accounting for 64,316 fatalities. The United States reported 301,902 cases accounting for 39,095 fatalities. Two weeks later we are now 110 days out with 2,356,475 global cases accounting for 162,070 fatalities. The United States reported 735,366 cases accounting for 39,095 fatalities. These numbers indicate we are not nearly out of the woods yet but they do suggest the spread is slowing.
The key metric in a pandemic is the acceleration of the virus. There is a difference between new cases added each day (velocity) and the change in new cases each day (acceleration). As there are more new cases each day than there was the day before, the virus is accelerating in a positive direction. We need that trend to reverse, meaning there may be more cases from one day to the next but was the number of more new cases less than the number of new cases the day before. When this occurs for a length of time we are going in a negative direction as the virus rate is decelerating. The numbers being reported, although startling high, suggest we are going in the right direction with an infection and fatality rate much lower than the original models suggested.
The original models for the United States that led to the shutdown were based on 2 million fatalities (1 – 3%) if nothing was done to slow the infection rate. The WHO estimated 3.4% worldwide. These numbers were projections based on very little data at the time. As more and more testing and better infection surveillance is facilitated, more accurate models will be created.
One of the latest studies from Stanford University is now under peer review inferring a much higher rate of asymptomatic infected individuals than what was thought. The study was performed in the geographic area of Santa Clara in northern California. At the inception of the study the county was reporting 1,000 known cases for COVID-19. Preliminary results showed an estimated 48,000 – 81,000 of the population translating into a rate of 50 – 85% higher than what was originally predicted. Using the same data, the research team is estimating the true infection fatality rate is 0.12 – 0.2%. It should be said, other researchers are claiming there may be flaws in the study beginning with the validity of the antibody test being used.
If the study is accurate, we may be getting to herd immunity through natural immunity. We know there are large portions of the population that have had the virus and are asymptomatic. In theory these people have developed the antibody that will prevent them from being reinfected and spreading it further. If enough of the population has the antibody from contracting the virus, the virus will not have a host to infect and will eventually die off, “Herd Immunity”. But here’s the rub, the people that will still be at risk are the ones that were compliant with washing their hands, wearing masks and social distancing. They never contracted the virus and as a result, do not have the antibody for immunity.
This puts them at risk in two ways. If we come out of sheltering too soon, this unknown population is likely to be infected and an unknown percentage of them will become symptomatic and die. Secondly, there may be a second or even third wave of the virus. Too much is unknown at this point, even with immunity. How long does it last? People that have had the mumps are immune for life but other types of coronavirus see immunity wane in a year.
As for the NBA returning, chairman of the board of Walt Disney Co., Bob Iger said it best, “it’s more about the data than the date”. The data comes from testing and we’re still months away from mass testing and at least a year away from a vaccine. This leaves the NBA in Limbo.
Commissioner Adam Silver said the NBA is committed to resuming the season but there is still no time table for a possible return or a deadline to cancel. As I said in my first blog about COVID-19, the public would be wise to follow what the NBA does. They have the best and brightest working on this and will make the most prudent decisions. Overall, things seem to be gong in the right direction. Even in New York City, the epicenter of the epidemic of COVID-19 in the United States, the curve seems to be flattening with the lowest death toll in more than two weeks. Governor Andrew Cuomo said the Coronavirus in “on the descent”.
It’s just too early to make a data-driven decision when the data is not there. Without sufficient data, you are just guessing.