Why Is Testing So Important? Answers from an Infectious Disease Expert

While Ohioans are in the midst of a gradual lifting of stay-at-home orders, renewed focus has come upon testing as a means of ensuring the fast rehabilitation of society. We speak with Dr. Bruce Walker, the Founding Director of the Ragon Institute of MGH, MIT and Harvard, on the topics of COVID-19, disease testing and the lifting of stay-at-home orders.

As many states in the U.S. approach lifting stay-at-home orders and social distancing restrictions, some governors and health officials have doubled down on calls for testing as the only safe way to reopen. And while protests and social media have highlighted some Americans’ urgent desire to “reopen” polls show that nearly 66% of people fear that state governments may lift restrictions on public activities too quickly.

Dr. Bruce Walker, an expert in infectious diseases and the immune system, said that with many stay-at-home mandates coming to their end, having information to act upon—in other words, knowing who is ill and who is not—allows us to act more quickly and accurately to mitigate the spread of the disease.

Walker is the founding director of the Ragon Institute, a world-renowned organization that brings together specialists from MGH, MIT and Harvard to advance understanding into infectious diseases, immunology and vaccine treatments. Since the outbreak of COVID-19, the institute has dedicated its resources to research on the novel coronavirus, from diagnostics to vaccine development. 

“There are certainly things that we can do that people won’t get infected and they are things we can apply right now,” he said.

The things we know can help are social distancing, wearing masks, handwashing and other basic protocol. But as these conventions remain largely unenforceable as individuals and businesses set up and follow their own guidelines, so testing remains a key tool for the government and public health officials to track, treat and mitigate COVID-19.

In pandemic situations, testing for COVID-19 is essential for a few reasons. Early detection allows for effective care to be provided for infected individuals and the tracing of people that may have come into contact with infected individuals. Through isolating potential routes that COVID-19 can spread, medical resources can also be better allocated for treatment of patients and the use of social distancing and stay-at-home policies can be reduced. 

“Hopefully by staying out of work, we’ve gotten to a point where the virus can be contained again by contact tracing and getting people isolated. That is certainly the hope,” he said. “I think we have to take this carefully and we have to rely on people to be more rigorous in terms of trying to prevent more infections from happening by doing the things that we know can help.” 

There are two main tests that have been used for detecting: a diagnostic test that determines whether someone is currently infected with COVID-19 and an antibody test that detects whether someone has had the virus and has formed antibodies to fight off the disease. Diagnostic tests are most important for treating, tracking and isolating patients.

The antibody tests, on the other hand, cannot reveal who is carrying the virus but have been developed as a potential means of bringing normality back. For many diseases (e.g. chicken pox), getting it once means you have immunity to getting it again. In these cases, getting a positive antibody test would suggest you are able to go about normal life without fear of contracting the disease. 

But it’s still not clear if COVID-19 falls into that category of diseases.

“The WHO came out and said again that there is no evidence that antibodies will protect people from reinfection. There’s no evidence to the contrary at this point either—we’re just lacking evidence about what we need,” Walker said.

Even without knowing exactly what the results of antibody tests imply, however, the market has been flooded with these tests. Regardless, they are useful in understanding just how many people have contracted the virus, especially those who showed little to no symptoms or simply weren’t tested when ill. The presence of antibodies can also be a useful tool for monitoring herd immunity, or the overall resistance of a community to the spread of disease caused by a significant number of individuals being immunized either through getting sick and recovering or receiving vaccine treatment.

The antibody tests currently in the market, however, are not all working as intended.

“A lot of those [antibody] tests are not accurate, but some of those are. The FDA gave out a lot of emergency use authorizations without actually screening the tests for accuracy. So some of them lacked specificity and sensitivity so they are not really giving us accurate answers,” he said. “But we have screened a whole bunch of them with a gold standard assay we developed and find that there are a couple of them that work well and a lot of them that give very erratic results.” 

Across the board, current testing is not enough. The United States currently performs about 250,000 diagnostic tests per day with the number of COVID-19 tests per capita rising to currently around 0.8 tests per 1,000 people, with a current percentage of confirmed cases at 16.5% (1.16 million cases out of 7.05 million tests) from testing. 

Generally, a higher percentage of positive-tested cases implies that there is not enough testing, with the ideal number at around 12%. According to a study done by Harvard researchers, the United States would have to get to a point of conducting a minimum of 500,000 daily tests to safely open. Other studies suggest we’d need even more testing, some saying up to 5-20 million tests a day. 

Tests conducted in Ohio.

For a state like Ohio, that would mean a minimum of about 18,500 tests a day, while the state’s current testing rate is  about 4,000-6,000 tests per day. 

In order to increase testing capacity, states like New York have begun to adopt broader measures for testing, including giving local pharmacies the ability to assist in coronavirus testing. According to Walker, for effective control of COVID-19, there needs to be ready accessibility to testing for those individuals that show symptoms or have been determined to have made contact with the disease through contact tracing.

“Ideally, you would have this in every doctor’s office, it would be available for people to do that. You’d have it in community settings where people can just go and do drive-thru testing. Ideally, we’d get to the point and we will, where it is not a nasopharyngeal swab, which is really uncomfortable, but just a saliva sample, an oral swab that can be used,” he said.

While availability of tests still remains scarce, many states have decided to move forward with re-opening, some more cautiously than others. For example, the Ohio Department of Health has created a plan that seeks to increase Ohio’s testing capacity to over 20,000 by the end of May while gradually re-opening sectors of society.

For Walker and his work at the Ragon Institute, thinking about re-opening includes strict, science-based protocol in the workplace.

“We are planning to open up the Ragon Institute by implementing the use of masks by everybody, and switching to two shifts so that people are physically separated and monitoring temperature and symptoms on a regular basis. We will track virus positivity and we will track antibodies and we’ll see if we are able to prevent infections from happening,” he said.

While tracking and tracing are effective tools to prevent the spread of disease, Walker says that he is hopeful that the development of a vaccine might be the ultimate way to become free of masks and distancing. Those efforts, though, are still projected to take about 12-18 months if all goes well, according to Walker.

But amidst the certainty that things will remain uncertain for quite some time, Walker has seen the scientific community rise to the occasion, giving their all to work toward more widespread and accurate testing and vaccine development. 

“It [has] shown that some people are really selfless and not worried about personal attributions in science, but worried about doing something about the epidemic and working together,” he said.

While we are consulting experts in the field to get answers to important questions during this crisis, new information and studies come out almost every day and much remains unknown regarding COVID-19. Midstory encourages everyone to follow all public health and safety protocols and exercise extreme caution. You can find out more about Ohio’s ongoing coronavirus response at https://coronavirus.ohio.gov/

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