More than two years since the US was hit by the first wave of Covid-19, many of us in science and medicine have paused at one point or another to think about our collective response, even as we continue to fight the virus and its new variants.
CDC’s collaborative approach, which recognizes the interconnectedness of humans, animals, plants, and their environments, known as One health, gained more popularity as the world experienced the effects of interspecies transmission of Covid-19. As a changing climate impacts human, animal and plant habitats and drives ecological transitions, our global risk of interspecies transmission, or zoonoses, and resulting future pandemics becomes even greater. World Health Organization predicts pandemics will occur more frequently [and] are spreading faster…” in the coming years.
It is critical that global government policies support One Health initiatives that promote biodiversity and conservation to prevent zoonoses before they occur. While prevention is the best measure, it is equally important to improve our preparedness so that we can respond to potential pandemic threats in a way that minimizes transmission and disease to the greatest extent possible.
Now is the time to assess our response to this pandemic, to determine what we have learned, where we could have done better, what has worked well, and how we can ensure that we are prepared for future scenarios in our current pandemic, as and for future pandemics.
Lessons learned from Covid-19: the critical role of testing
Following the emergency use authorizations of multiple Covid-19 vaccines and treatments, the risk of mortality from a Covid-19 diagnosis has decreased dramatically compared to the early days of the pandemic. Vaccine manufacturers used advanced science to develop, test, and produce vaccines in record time, which was well funded through government funding that ensured widespread availability. These actions have been 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 during the pandemic. In the early days, testing was largely incorporated into a containment strategy by isolating patients in hospitals and quarantining asymptomatic and mildly symptomatic patients at home. For most of the pandemic, routine PCR testing has been used to prevent large outbreaks in homes, workplaces and schools. Even now, like more than three quarters of Americans are vaccinated, testing distinguishes pathogens that cause similar symptoms to optimize treatment.
From a testing perspective, it’s fair to say that the US laboratory industry was unprepared for the sudden pressure it faced at the start of the Covid-19 pandemic. The early, unexpected spike brought into sharp focus the complexity of sourcing key diagnostic components, including nasal swabs, sample collection vials and media, reagents and sequencing equipment. He also highlighted some of the disadvantages of globalization and laboratory consolidation.
One of the reasons for our unpreparedness was that we had not experienced anything on the scale of Covid-19 in over a century. The most recent avian influenza (H1N1) pandemic of 2009, by comparison, was not a fatality event of 0.001 to 0.007 the percentage. Even the H3N2 pandemic of 1968 resulted in a 0.03 percent mortality rate. The death rate from Covid-19 is currently estimated at 1.2 percentemphasizing how much bigger this pandemic is compared to those of the last hundred years.
At the same time, the US health care system has evolved to delicately balance capacity with cost-effectiveness. Before the pandemic, the network of labs in the US was set up to respond to small spikes, most often associated with seasonal flu or other common viruses. Test supplies were cheaply produced overseas and overall production was adequate. In the case of Covid-19, the entire world experienced a simultaneous, constant need for supplies, while producing countries experienced aggressive lockdowns that affected manufacturing output. The waves were very large and producing countries kept their production for their own population, creating shortages.
In addition to supply testing challenges, the US has experienced challenges due to heavy consolidation within the laboratory industry over the past decade. The US laboratory network did not have the capacity to handle the large volumes of tests for which there was a sudden demand in addition to the usual demand for PCR tests related to other medical conditions.
Even reporting results requires unforeseen time and effort. Non-Covid-19 PCR test results are usually reported to specialist healthcare providers for very specific medical conditions. Adjusting the reports not only to reflect new parameters and HIPAA compliance for the lay reader, but also to issue significantly higher volumes of reports each day was another unexpected hurdle.
Developing towards better preparedness
The silver lining of the situation was that the diagnostics industry was able to respond and adapt 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 the expansion of our laboratory capacity. We have gone from a pre-pandemic level of molecular testing of 40 to 50 percent to PCR testing, which now covers about 70 to 80 percent of the volume. We are getting better at maintaining adequate capacity and scaling to meet increased needs.
We also find a good balance between test sensitivity versus speed or rapid testing. During the pandemic, we had to reassess the best test for each particular moment. Before the availability of the vaccine, there was a need to focus on susceptibility because testing was the only tool available to manage the virus. We needed to know for sure who had Covid-19 so we could limit the spread and provide early medical care.
As we have moved into a vaccine environment and the death rate from Covid-19 has decreased, the convenience of testing has become more important, and with it the greater prevalence of antigen testing. Antigen testing has limitations: it is a less effective containment tool and does not lend itself to accurate reporting of case numbers. However, there is a role.
As we began to understand the best program 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 cannot give an answer as quickly. We have found that antibody testing is not as useful as we originally thought it might be, and that knowing whether someone has had Covid-19 before is not as important as knowing whether they are currently carrying the virus.
We have also entered a period of laboratory innovation that has streamlined and improved processes in a lasting way. Assays for Covid-19 have been developed at record speeds and have the potential to inform future assay development for other pathogens. Home test kits, which had previously been subject to various hurdles, benefited from eager adoption by consumers. Hospital laboratories have developed shorter turnaround times for results with the promise of a better patient testing experience across a range of conditions for years to come.
A transport medium that inactivates dangerous pathogens in patient samples now offers improved worker protection, safer and faster collection, and enables temperature-agnostic transport and storage. Solutions like these have gained an integral place in everyday workflows in the short time since they were introduced.
It is encouraging to see how our industry has risen to the challenge and developed creative and intelligent solutions to meet this sudden and unexpected need. Of course, we will use the improvements we’ve implemented and the lessons we’ve learned as we manage the rest of this pandemic, as well as future ones, resulting in improved care overall. At the same time, it is important to protect what we have won. It is vital that government policies support the rapid scaling up of testing capacity and protect local production capabilities for all viral pathogens.
Beyond preparedness policies, we need to think ahead to policies that quickly identify the spread of zoonotic diseases to prevent or minimize the impact. The key tools and infrastructure used for this pandemic must be ready and available for the next wave or the next pathogen.
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