A Seattle epidemiologist who warned about the threat posed by novel coronavirus when it was a novelty now says he sees a path to stopping the pandemic.
But it'll take more than just staying at home for a couple of weeks, Trevor Bedford of the Fred Hutchinson Cancer Research Center said today in a series of tweets.
"This is the Apollo program of our times," Bedford wrote.
Bedford, who analyzed genetic data to figure out that the SARS-CoV-2 coronavirus had been spreading stealthily in the U.S. for six weeks, began with the standard advice on social distancing.
Although social distancing can "flatten the curve," a recently published study found that the strategy isn't likely to bring an end to the outbreak by itself. There's a good chance that the outbreak would rebound once the restrictions were relaxed.
The study, led by researchers at Imperial College London, concluded that stringent social distancing would have to be maintained until a vaccine is developed – which could take 18 months or more. And the financial cost of maintaining the strategy that long may be unacceptably steep.
"This is the catch-22 as presented by the report," Bedford tweeted.
Is there a way out? "I have hope that we can solve this thing by doing traditional shoe leather epidemiology of case finding and isolation, but at scale, using modern technology," Bedford said.
The first part of the strategy depends on a massive campaign of testing, followed by isolation for those who test positive. "If someone can be tested early in their illness before they show symptoms, they could effectively self-isolate and reduce onward transmission, compared to isolation when symptoms develop," Bedford explained.
He noted that such a strategy appears to be working in South Korea.
Getting enough tests has proven to be a problem in the U.S., and that's where Bedford's Apollo program comes into play.
"This rollout of testing could be achieved through at-home delivery of swabs with centralized lab-based processing, combined with drive-through testing facilities," Bedford said. "There are logistics involved in getting a result quickly, but it's really just logistics."
Plans for at-home sampling have surfaced a couple of times this month: The White House's plan to increase coronavirus testing envisions having LHC Group, a home healthcare services company, play a part in facilitating at-home testing.
Even before the White House unveiled its plan, there was talk of the Bill & Melinda Gates Foundation and Amazon Care teaming up on a home testing system.
Regardless of who does it, an at-home testing campaign would be costly and complicated. But as Bedford says, it's really just logistics.
The second part of the strategy involves using cellphone location data. Once a person tests positive, all the people who came into close contact with that person before the test results were available – as determined by matching up location data – would be alerted to get tested and go into self-isolation.
Bedford noted that Oxford epidemiologist Christophe Frazer and his colleagues have already looked into how such an instant-tracing strategy could work.
"A third, supporting, strategy: As the epidemic proceeds, get serological assays run on as many people as possible to systematically identify individuals who have recovered and are highly likely to possess immunity," Bedford wrote. "Individuals who have serological evidence of recovery and are no longer shedding virus can fully return to the workforce and keep society functioning."
Two types of serological tests for coronavirus immunity are being evaluated by the Centers for Disease Control and Prevention. Still more tests of this type have been developed in China and Singapore, and epidemiologists like Bedford say such tests will be key to locking down the virus for good.
"Together, I believe these (and other case-based) strategies can bring down the epidemic," Bedford said.
The key steps in the strategy – the easy availability of tests for the virus, the system for analyzing masses of cellphone location data and the tests for immunity – have yet to be nailed down. But laying out the plan in this way might at least give folks outside the research community a better sense of the big picture, and maybe give them fresh cause for hope as well.
Here's Bedford's 19-tweet thread, including charts and links:
I've been mulling over the @MRC_Outbreak modeling report on #COVID19 mitigation and suppression strategies since it was posted on March 16. Although mitigation through social distancing may not solve things I believe we can bring this epidemic under control. 1/19
— Trevor Bedford (@trvrb) March 19, 2020
But first, the report. @neil_ferguson, @azraghani and colleagues model COVID-19 epidemic outcomes under different intensities of non-pharmaceutical, aka social distancing, interventions. 2/19https://t.co/di1jA0TKcX
— Trevor Bedford (@trvrb) March 19, 2020
Different mitigation scenarios that include things like school closures, isolation of symptomatic individuals and quarantine of exposed household members, result in #flatteningthecurve and reducing mortality, but under the author's assumptions still result in an epidemic. 3/19 pic.twitter.com/3eVSGxkHF3
— Trevor Bedford (@trvrb) March 19, 2020
Given assumed severity of COVID-19 infections, this flattened epidemic is still severe, resulting in over 1 million deaths in the US and >250k deaths in GB, mostly concentrated in those over 60 and with underlying health conditions. 4/19
— Trevor Bedford (@trvrb) March 19, 2020
Alternatively, with stronger social distancing, the epidemic could be brought under control and effectively "suppressed". However, stopping this level of social distancing would result in a fairly rapid rebound as the population would still lack immunity to the virus. 5/19 pic.twitter.com/l5ROn1Lk8w
— Trevor Bedford (@trvrb) March 19, 2020
Managing this level of social distancing required for suppression while still having a functional economy and society would be difficult and it's not at all clear that this could be maintained for the ~18 months until we have a vaccine. 6/19
— Trevor Bedford (@trvrb) March 19, 2020
This is the catch-22 as presented by the report. 7/19
— Trevor Bedford (@trvrb) March 19, 2020
However, I'm not quite that pessimistic. Although I agree that basic mitigation efforts won't stop the epidemic, I have hope that we can solve this thing by doing traditional shoe leather epidemiology of case finding and isolation, but at scale, using modern technology. 8/19
— Trevor Bedford (@trvrb) March 19, 2020
There are two main case-based strategies that I see here, both related, as well as a supporting serological strategy. 9/19
— Trevor Bedford (@trvrb) March 19, 2020
The first strategy revolves around a massive rollout of testing capacity. We believe that a significant proportion of epidemic transmission is due to mild and maybe even asymptomatic infections (https://t.co/VuWXqrjPpx). 10/19
— Trevor Bedford (@trvrb) March 19, 2020
We also believe that a significant amount of transmission may occur in the window before symptoms develop (evidence from viral load dynamics https://t.co/LcL9L0B0gv, evidence from serial intervals https://t.co/YZ4ce18pSL). 11/19
— Trevor Bedford (@trvrb) March 19, 2020
These transmission routes can be reduced by a huge rollout of testing capacity. If someone can be tested early in their illness before they show symptoms, they could effectively self isolate and reduce onward transmission compared to isolation when symptoms develop. 12/19
— Trevor Bedford (@trvrb) March 19, 2020
This strategy of massive testing has been a cornerstone in South Korea's response (https://t.co/y5cVGXK7yz) and we're now seeing their epidemic brought under control without the stringent policies put in place elsewhere. Case counts in South Korea via @covid2019app. 13/19 pic.twitter.com/svdcKUkI9O
— Trevor Bedford (@trvrb) March 19, 2020
This rollout of testing could be achieved through at home delivery of swabs with centralized lab-based processing combined with drive-through testing facilities. There are logistics involved in getting a result quickly, but it's really just logistics, which can be solved. 14/19
— Trevor Bedford (@trvrb) March 19, 2020
The second, related, strategy is using cell phone location data combined with data on known positive cases to alert possible exposures to self isolate and get tested. Figure from @ChristoPhraser and colleagues who've considered this in detail. 15/19 pic.twitter.com/iAllsqE52E
— Trevor Bedford (@trvrb) March 19, 2020
This strategy targets testing capacity at most likely cases and serves to detect exposure events early, when isolation is most valuable. This cell phone location based approach is outlined carefully here: https://t.co/cu09jbd6zB. 16/19
— Trevor Bedford (@trvrb) March 19, 2020
A third, supporting, strategy: as the epidemic proceeds get serological assays run on as many people as possible to systematically identify individuals who have recovered and are highly likely to possess immunity. 17/19
— Trevor Bedford (@trvrb) March 19, 2020
Individuals who have serological evidence of recovery and are no longer shedding virus can fully return to the workforce and keep society functioning (especially important for those at the clinical front lines). 18/19
— Trevor Bedford (@trvrb) March 19, 2020
Together, I believe these (and other case-based) strategies can bring down the epidemic. This is the Apollo program of our times. Let's get to it. 19/19
— Trevor Bedford (@trvrb) March 19, 2020
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