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More than two years since the U.S. was hit with the first wave of Covid-19, many of us in the fields of science and medicine have stopped at one point or another to reflect on our collective response, even as we continue to battle the virus and its new variants.
CDC’s collaborative approach that recognizes the interconnection between humans, animals, plants and their environments, known as One Health, has gained greater currency as the world has lived the effect of the cross-species transmission of Covid-19. As changing climates impact human, animal and plant habitats and spur ecological transitions, our global risk of cross-species transmissions, or zoonotic disease, and the resulting future pandemics becomes even greater. The World Health Organization predicts pandemics will, “emerge more often [and] spread more rapidly…” in future years.
It is critical that global government policies support One Health initiatives that promote biodiversity and conservation to prevent zoonotic disease before it occurs. While prevention is the best measure, it is equally important that we improve our preparedness so that we are able to respond to potential pandemic threats in a way that minimizes transmission and sickness to the greatest extent possible.
Now is the moment to evaluate our response to this pandemic, to determine what we learned, at which points we could have managed better, what worked well and how we can ensure we are prepared for future variants in our current pandemic as well as future pandemics.
Lessons learned from Covid-19: the critical role of testing
Since the Emergency Use Authorizations of multiple Covid-19 vaccines and treatments, the mortality risk of a Covid-19 diagnosis has decreased dramatically compared to the first days of the pandemic. Vaccine manufacturers leveraged advanced science to develop, test, and manufacture vaccines in record time, that was well-resourced through government funding, which ensured broad availability. These actions were instrumental in saving lives, and restoring the economy and everyday life to some semblance of normalcy during the ongoing pandemic.
Testing has played a significant role throughout the pandemic. In the early days, testing factored largely into a containment strategy by isolating patients in hospitals and quarantining asymptomatic and non-severe symptomatic patients at home. Through most of the pandemic, routine PCR testing has been used to prevent large outbreaks in homes, work places, and schools. Even now, as more than three-quarters of Americans are vaccinated, testing differentiates pathogens that cause similar symptoms in order to optimize treatment.
From a testing perspective, it is fair to say that the U.S. laboratory industry was not prepared for the sudden pressure it faced at the beginning of the Covid-19 pandemic. The early, unexpected surge brought into stark view the complexities of sourcing key diagnostic components including nasal swabs, sample collection vials and media, reagents and sequencing equipment. It also underscored some of the shortcomings of globalization and laboratory consolidation.
One reason for our lack of preparedness was not having experienced anything at the scale of Covid-19 for more than a century. The most recent (H1N1) avian flu pandemic of 2009, by comparison, was a non-event with mortality at 0.001 to 0.007 percent. Even the 1968 H3N2 pandemic carried a 0.03 percent mortality rate. Covid-19 mortality currently is estimated at 1.2 percent, underscoring how much larger this pandemic compared to those over the last hundred years.
At the same time, the U.S. healthcare system has evolved to delicately balance capacity with cost-efficiency. Prior to the pandemic, the U.S. lab network was set up to respond to small surges, most often related to seasonal flus or other common viruses. Testing supplies were inexpensively produced overseas, and production was generally adequate. In the case of Covid-19, the entire world experienced a simultaneous, sustained need for supplies while producer countries underwent aggressive lockdowns that impacted manufacturing production. Surges were very large, and producer countries retained their outputs for their own populations creating shortages.
In addition to testing supply challenges, the U.S. experienced challenges due to heavy consolidation within the lab industry over the last decade. The U.S. lab network did not have the capacity to manage the large volumes of tests for which there was sudden demand on top of the usual demand for PCR testing related to other medical conditions.
Even results reporting required unforeseen time and effort. Non-Covid-19 PCR test results typically had been reported to specialized healthcare providers for very specific medical conditions. Adjusting reporting not only to reflect new parameters and HIPAA-compliance for a non-specialized reader, but also to issue significantly larger volumes of reports each day was another unexpected hurdle.
Evolving toward better preparedness
The silver lining of the situation was that the diagnostics industry was able to respond and flex to the unexpected as we navigated new territory, albeit with some transition bumps and learnings along the way. One important change the industry has made is in expanding our lab capacities. We moved from a pre-pandemic molecular testing rate of 40 to 50 percent to PCR tests now comprising about 70 to 80 percent of volume. We are getting better at maintaining adequate capacity and scaling to meet increased need.
We’re also finding a good balance between test sensitivity versus speed, or rapid testing. Throughout the pandemic, we’ve had to reassess the best test for each particular point in time. Prior to vaccine availability, there was a need to focus on sensitivity because testing was the only tool available to manage the virus. We needed to know with certainty who had Covid-19 so that we could contain the spread and provide early medical care.
As we moved into a vaccine environment and Covid-19 mortality decreased, testing convenience became more important, and with it, a greater uptake of antigen testing. Antigen testing has limitations: it is a less effective containment tool and doesn’t lend itself to accurate caseload reporting. However, it has a role.
As we began to understand the best utility for each type of test, we also discovered their limitations. Antigen tests may not be the best option during a period of rapid and aggressive spread. PCR tests are more accurate, but can’t provide as quick an answer. We discovered that antibody testing was not as helpful as we initially thought it might be and that knowing whether someone had had Covid-19 previously was not as important as knowing whether they were currently carrying the virus.
Additionally, we entered a period of lab innovation that has streamlined and improved processes in long-lasting ways. Covid-19 assays were developed at record speeds and have potential to inform future assay development for other pathogens. At-home test kits, previously subject to a variety of hurdles, have benefited from eager uptake by consumers. Hospital labs developed tightened result turnaround times with the promise of better testing experiences for patients across a range of conditions for years to come.
Transport media that inactivates dangerous pathogens in patient samples now offers improved protection of workers, safer and faster collection and enables temperature-agnostic transport and storage. Solutions such as these have gained an integral place in everyday workflows in the short period of time since they were introduced.
It’s encouraging to see how our industry rose to the challenge and developed creative and smart solutions to meet this sudden and unexpected need. Certainly, we will draw on the improvements we implemented and the learnings we gained as we manage the remainder of this pandemic as well as future ones, with an outcome of improved care overall. At the same time, it is important that we protect what we have gained. It is vital that government policies support rapid scaling of testing capacity and protect domestic manufacturing capabilities for all viral pathogens.
Beyond preparedness policies, we need to think forward to policies that rapidly identify the spread of zoonotic disease to prevent or minimize the impact. The key tools and infrastructure that have been used for this pandemic must be ready and available for the next wave, or the next pathogen.
Photo: santima.studio, Getty Images