Biden’s 500 million COVID tests do not go far enough

President Biden’s plan to make 500 million at-home test kits available at no cost later this month sounds great — but does not go far enough. Moreover, widespread use of at-home tests requires a shift in how to track the virus and its impact on communities. 

The omicron surge is happening now. The holidays clearly fomented many of the new cases, as people gathered to enjoy meals and festivities with family and friends. Even with all the appropriate safety measures taken to stay infection-free, omicron’s high level of contagiousness exploited any weak links in these precautions. That is why the number of daily cases reported by the Centers for Disease Control and Prevention (CDC) are at record levels. 

The emergence of omicron has encouraged more people to test, also reported by the CDC at record levels. However, these are just the reported tests, not the at-home tests that many are now using to get a snapshot of their infection status. Including at-home tests, millions of tests are being administered every day. 

The 500 million test kits that will be available shortly are welcome, but represent a “drop in the bucket” for what the nation needs. For example, 250 million people self-testing twice in a week will exhaust all the promised at-home tests. What is needed are 500 million at-home test kits available every single week. The logistics of manufacturing and distributing such tests, particularly the last mile of getting them into people’s hands, is daunting.

At-home test kits make it more difficult to track national infection trends, since many who test positive have little reason to report their infection. For example, Vermont has asked their residents to report their positive results, but there is no way to ensure that people do so. This means that the number of cases reported nationally by the CDC will significantly undercount the actual number of infections.  

In response, the CDC must shift their focus to hospitalizations as the metric for tracking the spread and impact of the virus. Given that hospitalized COVID-19 patients are a captive audience, taking a full history of their vaccination status, what vaccines they received, when they received them, as well as whether they are aware if they had prior infections are critical pieces of data that will provide a more informative picture of the COVID-19 landscape.  

At-home tests are most useful immediately prior to some event, like a family gathering or visiting friends. However, their accuracy carries with it some limitations.  

If a person tests positive, they are highly likely to be infected. On the other hand, a negative test may only be accurate around 85 percent of the time. At-home tests are most beneficial when a person uses them multiple times within a narrow time window. The need for such a large number of tests would place further pressure on the supply chain as demand overwhelms supply.  

Polymerase chain reaction (PCR) tests offer a more reliable assessment of infection status. The problem with them is that it typically takes several days to get a lab-processed result, effectively making them impractical and pointless for most people.

A test result can only provide a snapshot of a person’s infection status. Once a person interacts with other people, exposing themselves to infection risk, a negative result becomes meaningless. That is why people in high-risk occupations like health care and the service industry, who have high infection risk exposure, require frequent testing to stay ahead of any infections that they may contract and spread.

We cannot test ourselves out of the pandemic nor can the unvaccinated test themselves to safety. Indeed, testing is not a substitute for vaccination. Testing is a tool that informs people of their infection status, enabling them to take the necessary precautions to avoid infecting others. Such information is critical to reduce the basic reproduction number of the virus, the average number of people that a contagious person infects.

To gain the upper hand on the virus requires multiple layers, vaccination, face masks, social distancing, hand hygiene and testing, each of which has its deficiencies, but collectively can provide an effective barrier to limit the spread of the virus and reduce its impact on communities. Relaxing or ignoring any one layer makes communities more vulnerable to infection spread and the associated consequences, including more virus mutations. 

At-home tests are a useful tool in combating the spread of the virus. But having access to 500 million at-home tests, as the president promises, does not go far enough. It is a step in the right direction, but a much larger leap is needed to reinforce the testing layer that can help move our nation more quickly to a safer place for all.   

Sheldon H. Jacobson, Ph.D., is a founder professor of Computer Science and the Carle Illinois College of Medicine at the University of Illinois at Urbana-Champaign. He applies his expertise in data-driven risk-based decision-making to evaluate and inform public health policy.