Contributed Commentary by Paul Chapman and Harald F. Stock, Domus Diagnostics
April 22, 2022 | At the height of the Omicron surge this winter, at-home rapid tests and PCR testing were hard to come by for everyone. But it was especially hard for people with low-incomes, non-native English speakers, and immigrant communities. Many of these people work in jobs that can’t be done remotely, putting them at risk of contracting SARS-CoV-2 and becoming seriously ill.
The Biden administration has tried to alleviate the testing shortages by shipping free, rapid antigen tests to tens of millions of Americans. But rapid antigen tests are most effective in detecting people that are symptomatically ill. Nucleic Acid Amplification Testing (NAAT) – which is a category of viral diagnostic tests that includes PCR (polymerase chain reaction) and RT-LAMP (reverse transcriptase loop-mediated isothermal amplification) - is more sensitive and less likely to result in a false negative.
Along with more eligible people being vaccinated, an affordable, accessible NAAT test for the masses is the most effective way to live with the virus rather than being dominated by it again.
Americans have good reason to be optimistic, with cases and positivity rates declining. But much of the rest of the world, especially Africa and parts of Asia, still has lower immunization rates. Additionally, the emergence of the BA.2 variant and a surge in cases in China make it hard to say we’re completely out of the woods. And while emerging variants have been less virulent, they are still dangerous for vulnerable parts of the population.
Public health officials in the U.S. and other countries should take advantage of this lull in cases to build up capacity of NAAT testing that can be done affordably and at scale, while continuing to persuade the unvaccinated to get immunized.
Why The Math On Existing At-Home Tests Doesn’t Add Up
Numerous studies have found that routine, asymptomatic COVID testing should be done as frequently as 2-3 times per week, especially in high-risk environments. Abbott’s BinaxNow COVID Antigen (Ag) test is typically priced at $23.99 for two tests. That means to test a family of four twice per week would cost close to $400 per month. And, because of the high rate of false negatives with Ag tests like these, this approach wouldn’t be effective in detecting the virus early and, hence, reducing transmission of the virus to others.
Testing regularly at home with any of the NAAT tests currently available on the market is even less attainable for ordinary families. Tests from Detect and Cue Health require the purchase of a base device and charge separately for each single-use test. The Detect base costs is $39, while the Cue Health base (Reader) is $249. Each Detect single-use test costs $49, while Cue tests are about $75.
This means that routine, at-home Nucleic Acid testing would cost a family of four upwards of $1,600 per month, assuming twice-weekly tests for everyone. For many households, that exceeds the cost of their mortgage.
Keep in mind that in many cases, testing twice per week isn’t enough. If you’re a caregiver for an aging parent or someone with a compromised immune system, regardless of your vaccination status, you may need to test daily if you’ve had a close contact with someone who tested positive.
Getting routinely tested at a community PCR testing site isn’t realistic for many families either. During the recent surges, there were widespread reports of people having to stand in line in the cold for three or more hours.
The Impact Of Inequitable Access To Diagnostics
A December 2021 article published by the Lancet COVID-19 Commission noted an “urgent need for further investments to develop and scale up access to diagnostics” as populations in low- and middle-income countries have faced significant shortfalls of vaccine and testing supplies. The article further pointed out the “unfair competition” due to governments’ reliance on a relatively small number of diagnostics manufacturers.
Research from GoodRx revealed that 67 million Americans live in COVID testing “deserts.” Due to geographical barriers, people living in these areas need to travel an average of 22 miles to the nearest COVID testing site.
Additionally, not only are tests in short supply during significant surges, but so is laboratory capacity. At times of significant testing demand, some laboratories experienced a shortage of staff as many employees were out sick, lengthening the turnaround time to process PCR tests from one day to 2-3 days or more! We could see significant lab capacity shortages again during the next pandemic.
A lack of accessible, fast, reliable testing can lead to more viral transmission. In one study, participants were asked to imagine they have symptoms consistent with COVID along with a clinical diagnosis from their physician. People who had no testing available in this hypothetical scenario were more likely to engage in behaviors that facilitate COVID transmission compared to those who received a “positive” test result.
There is a strong case to be made for ongoing, frequent surveillance testing, especially in countries with lower vaccination rates. Many countries, such as India, Switzerland, Germany, Denmark, Sweden and elsewhere, have reduced testing requirements, while the U.K. and other countries have scaled back quarantine requirements. Countries that have more vulnerability to Omicron, because of lower vaccination rates and fragile healthcare systems, could benefit from asymptomatic NAAT testing at scale.
A Race To Innovate
Given this shortage of affordable, accurate testing, more innovation and collaboration between public, private and academic organizations is needed. NAAT tests that are affordable for the average family, widely available and don’t require days of processing in a lab should be the ultimate goal for the future of COVID diagnostics now and for pandemic preparedness tomorrow.
Hopefully, the approved vaccines will be more equitably distributed and more of the eligible population will get their shot. Until that happens, there are possible surges and variants lurking around the corner. Affordable, convenient, accurate diagnostic testing at scale should be high on the priority list for everyone involved in public health as the best way to navigate the uncertain short term.
Paul Chapman is the president and CEO of Domus Diagnostics and can be reached at paul@domusdx.com. Harald F. Stock is the co-founder and executive chair of Domus Diagnostics and can be reached at harald@domusdx.com.