Plenty of people are calling for more COVID-19 testing. Some estimates require the United States to achieve 20-30 million tests per week in order to reopen the economy – a roughly 20x increase of our current testing capacity. The logic is sound – more testing, both for the virus and for antibodies, allows us to get a true picture of the situation on the ground. It could potentially allow for us to give “immunity passports” to people, although there is no hard, proven evidence for immunity after infection. In an ideal world, testing millions of people daily would solve many of our problems, and allow us to reopen safely.
There are two main types of tests – serological tests, which test the blood for antibodies, and RT-PCR tests, which utilize a nasal swab to test for the virus. The serological tests are largely still in development, and at present, have too high of a false positive rate to be used, and even if accurate, will likely be used to test for antibodies to grant “immunity passports”, rather than to test for the virus itself. RT-PCR tests can be more easily conducted, and it is these tests that we will focus on.
The RT-PCR tests require complex reagents – enzymes and buffers – to actually function. Without these reagents, the test is completely worthless. The tests also require nasal swabs, although these are easier to manufacture than reagents. Washington DC is already suffering from a testing supply shortage. Moreover, suppliers of reagents and test kits have already ramped up production as much as possible – test kit demand is so high that there is no incentive for reagent suppliers to not ramp up production. At this point, the testing problem is more of a fundamental physics problem than an economic problem – if a company could hit a magic button and increase its production of testing supplies 10-fold, they would undoubtedly do it, even if they had to bear the upfront costs and production costs.
In total, the world has probably conducted around 50 million COVID-19 tests. This is a very rough estimate – some countries, the largest being the People’s Republic of China, have not published figures for the number of tests conducted. This gives us a general indication of the difficulty in increasing reagent and test kit production. To conduct 20-30 million tests per week, the US would need to conduct twice the number of tests the entire world has conducted since the outbreak began in January. This problem is dramatically worsened when one considers the fact that every country on Earth wants to scale up testing – the EU has 100 million more people than the US; Russia has roughly half the population of the US, and Turkey and the UK are another 80 million and 60 million each. All of these political bodies are currently facing severe COVID-19 outbreaks, although new case growth has declined substantially in the EU and Turkey. Mass testing is the closest thing to a holy grail for politicians – they can save the economy and protect people’s health. All together, assuming all of these nations pursue mass testing – and this analysis excludes giants like India, Indonesia, Pakistan, and the more than 1 billion people who live in Africa – we are likely looking at a demand of 100 million COVID-19 tests per week.
The closest comparison we have is World War II. In this war, using the example of American warplane production, the United States went from producing 3,000 planes a year to 45,000 planes a year from 1940 to 1945. This represents a 15x ramp over the course of five years. America currently runs around 1.5 million COVID tests per week – to get to 20-30 million tests per week would require a 15x ramp over the course of a few months. There are obviously differences between airplane production and reagent production, but arguably it was easier to ramp up production in wartime than today. The age of COVID-19 is the age of massive supply chain disruptions, and in a globalized world, this is greatly harmful, in contrast to the localized supply chains of WW2.
Testing is obviously important, but it is not a panacea, and it will not provide us a golden ticket. America needs to double down on social distancing, potentially enacting stricter restrictions than what is currently in place, and eradicate the virus – as China, New Zealand, and Vietnam have – and then reopen, with massive stimulus packages to bolster the economy.