NEW YORK – The likely evolution of COVID-19 from a pandemic situation to something more resembling an endemic disease raises potential challenges for clinical laboratories and test developers as they aim to maintain the ability to increase the capacity as needed, but without overcommitting resources.

As they have throughout the pandemic, issues such as staffing shortages and supply chain gaps, combined with fluctuating demand, could make it difficult for labs and suppliers to calibrate their testing approaches.

This difficulty could be compounded by a decline in support from the federal government. Over the past year, the Biden administration has provided billions of dollars in funding to support the development and production of COVID-19 tests. A few weeks ago, however, Congress pulled $15 billion in emergency COVID-19 funds from a $1.5 trillion spending bill, a move the White House says could have a impact on the country’s testing capacity.

“The money that has been allocated for testing so far has almost entirely been spent on testing and getting us through the three different [COVID-19] spikes we’ve had this year,” said Tom Inglesby, senior adviser to the White House COVID-19 Response Team, following Congress’s decision to cut COVID-19 funding. “But we’ve been pretty clear that this is just the beginning of what will be needed for testing and other administration priorities.”

“We’ve heard consistently from congressional leaders that no one wants to go back to the kind of restraints we saw in December and January where people lined up in certain places. [for molecular testing] and we didn’t have the rapid tests we needed,” Inglesby added. “We know we’ve had a lot of support, but we also know that doing this kind of work will take public-private partnerships, government supporting industry, and building the systems we need for the long term. “

Testing is at the center of a key program in the COVID-19 preparedness plan the White House released this month – the Test to Treat initiative, which aims to put testing capacity in pharmacies and other places where patients can get tested for COVID-19 and fill a prescription for antiviral drugs like Pfizer’s Paxlovid. It is expected that by making testing and treatment available at the same time, individuals can start taking antiviral drugs early in the infection, when they are most effective.

Speaking in mid-March, Inglesby said on the first day of enrollment, more than 1,000 pharmacy clinics signed up to participate in the program. He said the administration ultimately aims to have thousands of participating sites across the country.

Test to Treat will rely primarily on rapid antigen tests, which provide results within minutes, allowing individuals to fill an antiviral prescription during the same visit if needed. Access to rapid COVID-19 antigen tests was a problem in the United States, although the federal government has taken steps in recent months to remedy this situationawarding major supply contracts to test vendors, investing $1 billion to expand access to rapid tests, and establishing a test evaluation program to support the Food and Drug approval process United States administration.

According to estimates from the Health Catalysts Group and COVID-19 Response Advisors, which have tracked COVID-19 testing capacity throughout the pandemic, rapid antigen testing capacity has grown steadily over the past few months, from from 315 million tests per month in November 2021 to 722 million in February. The ability to test to treat also benefits from the fact that the program will serve symptomatic people in person. Many of the difficulties of access with regard to rapid antigen tests have revolved around a lack of sufficient over-the-counter tests for use in symptomatic and asymptomatic people.

A possible downside of the program’s reliance on rapid tests is that these tests are less sensitive than molecular tests early in infection, which is when antivirals are most effective. This raises the possibility that some positive people may be missed.

“There’s a trade-off both ways,” Inglesby said, noting the longer turnaround time required for molecular testing. He suggested that symptomatic people who receive a negative result should serial test or consider ordering a molecular test.

Mara Aspinall, a practice professor at Arizona State University’s College of Health Solutions and a consultant with COVID-19 Response Advisors, said she thinks the rapid tests are a good fit for the program. She noted that while these tests “could have false negatives” early in the infection, Paxlovid should be started within five days of the onset of symptoms, not the onset of the infection itself, a window in which rapid antigen tests generally have good results. performance.

While Test to Treat will rely primarily on rapid antigen testing, molecular testing is also expected to continue to play a role in the management of COVID-19, although changing demand poses a challenge. for laboratories.

Robert Boorstein, medical director of Brooklyn-based Lenco Diagnostic Laboratory, said that with the arrival of the Omicron variant this winter, his lab has seen demand for molecular testing increase two or three times. The number of cases has since fallen dramatically, but the New York area, where Lenco does much of its testing, has seen an uptick in recent days as the Omicron BA.2 subvariant has begun to spread. In the region.

He said the increase in demand his lab saw this winter was “within the range of normal variation.”

“It’s when you start to increase five to 10 times that you have to scramble,” he said, citing staffing as a major issue labs will face in this situation.

Another likely challenge, Boorstein said, will be inventorying reagents and other testing supplies.

“How much inventory will people normally keep on hand? It varies wildly, but let’s say for a normal, predictable amount of testing, around two months,” he said. “If suddenly your testing rate increases by a factor of 10, you’ll use up your available inventory in about a week, and if everyone increases at the same time, it’s going to create a shortage.”

Since many reagents degrade over time and need to be replaced, manufacturers are also unlikely to keep enough materials to meet tenfold peaks in demand, Boorstein said. “It’s not like storing oil or butter. The fact that they hold inventory won’t prevent it from expiring.”

The Biden administration has reached out to the testing industry to ask how the government could help it manage uncertain levels of testing demand.

“We asked for a series of things from the industry, their best input and recommendations for managing this type of market volatility,” Inglesby said. “How they would advise us to strengthen the infrastructure to maintain it in times when demand is very low.”

He said the administration hopes over the next few months to issue requests for proposals that address identified needs.

“But that will entirely depend on whether or not we can get congressional support to do this work,” he said.

Automation is a potential tool to meet the challenge of fluctuating demand. SummerBio, based in Menlo Park, Calif., has built a highly automated CLIA lab that it says will be able to adapt effectively to ongoing changes in COVID-19 testing needs. In February, the California state government released its SMARTER plan, which outlines its long-term strategy to deal with COVID-19. Among its components is a call to maintain a total statewide testing capacity of at least 500,000 tests per day. The SummerBio lab, which will become fully operational in April, will be able to handle a substantial part of it, running up to 240,000 molecular tests per day.

Importantly, said Sasha Seletsky, the company’s co-founder and chief commercial officer, the lab’s high level of automation will allow it to quickly scale capacity up and down as needed.

“We can process 10,000 samples a day, and then within weeks we can process 100,000 samples a day,” he said, noting that in the case of Omicron, the lab has increased its testing volumes tenfold.” over a few days.”

Pandemic Response Lab (PRL), the COVID-19 testing company launched by Queens-based lab automation company Opentrons, is also relying on automation to help it manage rapidly changing testing needs. .

“As the pandemic tends towards a more endemic situation, I think everyone is aware of the potential next variant, the next Omicron, the next Delta, and the need to be able to respond to it and increase the capacity to demand,” said Jon Laurent, R&D Director at PRL.

“At PRL, the lab was really built around this central idea of ​​enabling rapid scale-up,” he said, noting that during the Omicron push, the facility was able to double its capacity. from around 30,000 tests a day to over 60,000 in about a week. .

Laurent said a combination of extensive automation and a modular process design enables rapid scaling, allowing the lab, for example, to reassign staff to different parts of the workflow as needed.

Even so, PRL expects to execute its operations with significant wiggle room to allow for fluctuations in testing.

“We’ve significantly increased our capacity in response to recent surges, and we’ve kind of left it there because we see no reason to dismantle parts of the lab given the potential for another surge at any time,” Lawrence said. He noted that this capacity overrun may in the future be supported by new non-COVID-19 tests that the lab plans to introduce, but that “we will still maintain a significant buffer to manage COVID at the to come up”.

SummerBio’s Seletsky said that for the lab industry to maintain the capacity to rapidly scale up COVID-19 testing indefinitely, “would likely require some level of investment and maintenance from state and federal governments.”

He said the company was continuing to work out its longer-term business model, exploring what combination of non-COVID-19 testing and other potential funding sources like government contracts would make the most sense.