How Many Tests Do We Really Need?

(Posted on Thursday, April 23, 2020)

We are all eager to return to normal or at least a new normal. Today’s limits on the availability of tests is the key bottleneck to re-opening We all know more tests are needed. But how many more?

Given the urgency to restart our economy this is no time to be timid. Every public health official outlines three criteria for ending lockdown.

Identification of those infected.

Contract tracing to identify those exposed.

Isolation of those exposed until there is no longer a risk of transmission.

How many tests do we need? Ideally all 155 million workers should be tested before returning or continuing to work. People should not have to go to work fearing for themselves and their families. All 80 million students (K through 12 and college) should be tested before returning to classrooms, which are ideal settings for disease transmission. All those over the age of 65 (about 50 million) should be tested as they are at high risk.

According to the Harvard Roadmap to Pandemic Resilience, we may need as many as 5 million tests a day by June and 20 million tests a day by July, that translates to 10 billion tests per year, in excess of my estimates here.

Testing is not a one-off exercise. Each person should be tested a minimum of three times over a fifteen day period to account for low and undetectable virus in early stages of infection. Additional testing of all contacts of an infected person will be needed until an effective vaccine is developed and those vaccinated develop protective immunity.

Developing and deploying a vaccine is estimated to take a year or more. Developing protective immunity once vaccinated may require another six months and repeated boosters, as is the case for most vaccines. Therefore, the capacity for large scale testing must be in place for many months and up to two years perhaps. This simple math adds up to about one billion tests for the initial round and another billion tests over the next two years, about one to two thousand times as many tests as are currently planned.

The need for two billion tests far outstrips any current capacity. Therefore, I call on the Federal Government to create a crash program to develop the instrumentation and materials necessary. Manufacturing the machines and producing the materials is a relatively simple engineering problem, as the technology already exists. We have the technology to provide results on site, within 5 to 10 minutes of the test. What is lacking is resolve and scale. We are America. We can do it!

Once developed the instruments and all the necessary materials should be made available throughout the country at no cost. The tests themselves must be administered by local public health authorities. It will be the responsibility of each state, once provided the instruments and testing materials, to deliver the service to its people. I estimate that the cost per test, when done at scale, will be less than one dollar per test. It is a small investment relative to the cost of the economic shutdown.

Read full article on Forbes

Originally published on Forbes (April 23, 2020)