How deadly is the coronavirus? How much of the population has already been infected? How widespread is immunity? The models politicians are relying on to make radical decisions in the COVID-19 crisis aren’t always 100 percent reliable.
It’s a large-scale experiment unlike any other: Eighty million people across Germany are trying to protect themselves from a virus, with tens of thousands of them already infected — a number that is increasing by the thousands each day.
Stage two, the shutdown of public life, has long since begun. Everyone is listening to science, hanging on every word from virologists and epidemiologists. The mantra: flatten the curve. If too many people get sick at once, they warn, there won’t be enough intensive care beds for the most severe cases.
But how many infections can be prevented by closing schools? To what extent does closing the borders help? No one can say for sure. The effectiveness of strict shelter-in-place rules, such as those put in place by Italy and Spain, is also entirely uncertain.
With a lack of concrete knowledge about the adversary, the only thing politicians can do in their haste is experiment. Over the next few weeks, the measures taken in the fight against the novel coronavirus and COVID-19 must be monitored and, if necessary, adjusted. But sooner or later, the question will arise as to how long extraordinary measures like this can be kept in place. And above all: What happens next?
In China, to be sure, the strict epidemic regime is now being carefully relaxed in the hope that the number of infections won’t begin to rise again immediately.
Optimists believe that COVID-19 can indeed be stopped by this initial response and that the virus can be kept under control over the long term with just a low number of infections.
A Protracted Battle?
Other researchers expect the battle to be more protracted. They fear the pandemic will flare up repeatedly despite all the measures taken.
But all forecasts are based on model calculations in which unknown factors are lurking. For example: How contagious is a person who is carrying the virus? How many infected people will actually get sick with it? How many of those who do fall ill will actually die?
Scientists rely on plausible values when making forecasts. Normally, they also indicate how likely it is that their values are inaccurate. But such margins for error aren’t particularly helpful to politicians at the moment because they have to make concrete decisions. And it currently appears that they are doing their best to prepare for the worst possible pandemic path.
A much-cited study, compiled by a team led by epidemiologist Neil Ferguson at Imperial College in London, supports their pessimism. Ferguson’s calculations suggest that the fight against the virus is likely to drag on for years in several grueling stages. The crisis won’t end, according to this view, until a vaccine is found.
This image of the future is based on complicated calculations. Ferguson’s team used mathematical models to develop a simulated world, populated with households, schools and businesses of various sizes, all based on data from the last British census. The age distribution of the residents also roughly corresponds to the census.
Such a virtual world allows for the study of the spread of a pandemic. Most importantly, though, it enables researchers to simulate diverse measures for containment. Is it enough to isolate only the most vulnerable people older than 70 years of age? And to what extent can closing schools help?
The findings of the report were sobering. Half-hearted measures appear to help little, it found. The only thing that showed success was deployment of the entire arsenal of measures, including the social distancing requirements in all segments of society. Otherwise, the virus would continue to multiply to such an extent that a large share of the seriously ill would have difficulty receiving any treatment at all. In Britain, that would mean more than 250,000 deaths and more than a million in the United States.
Germany wasn’t included in the study’s calculations. But even here in a country that has many intensive care beds compared to other countries, capacities would likely be quickly exhausted, if the study’s calculations are to be believed.
But a radical shutdown can’t be sustained indefinitely. As such, Ferguson suggests temporarily loosening containment measures at points when the spread of the virus has slowed — until the incidence of infection starts increasing again.
A Very Rough Approximation
The Imperial College study received considerable international attention. In Britain, it is viewed as the catalyst for the country’s shift toward a more radical containment policy. Ferguson’s team are among the best in the world in their field. But even their impressive simulation offers only a very rough approximation of reality. And beyond that, critics have pointed out some rather odd contradictions in the figures.
The most serious objection came from researchers at the New England Complex Systems Institute in Cambridge. They reject the finding that the spread of the virus would continually recur. Ferguson, they argue, failed to take into account one important countermeasure in his simulation: the tracking down of contact persons of infected individuals. In instances where these people are quarantined at an early stage, it can indeed prevent chains of infection from developing.
For that to succeed, however, it is first necessary to reduce the number of virus carriers to below a certain threshold – several thousand perhaps. Only then would it be feasible to follow up each individual case.
Fortunately, the behavior of the virus may make such an approach more promising. It seems to frequently spread in smaller, more contained circles: Family members, friends and work colleagues often infect each other. That means that even a search limited to immediate surroundings could have a strong impact.
In South Korea, helpers are systematically visiting the contacts of people who have fallen ill with the disease, relying in part on data from mobile phone tracking. At the same time, the country is testing more vigorously than any other. This has allowed South Korea to keep its number of deaths low without having to resort to a complete shutdown, at least for the time being.
American epidemiologist Trevor Bedford believes the pandemic could be brought under control elsewhere if South Korea’s example were to be followed.
A Need for Antibody Testing
He also advises that as many people as possible be tested for the presence of antibodies against SARS-CoV-2, the official name for the virus that causes COVID-19. Such tests only produce results several days after an infection has occurred, making it useless in early-stage virus detection. But it can be used to find people who have already recovered from a coronavirus infection without having noticed that they had it. They could then be considered immune.
This has two advantages: It would shed light on how far the virus has spread undetected, which remains one of the most important unanswered questions. And it would reveal a growing number of people who are resistant to the virus. They no longer get sick and they can’t infect anyone, which would make them ideal for working in hospitals or helping those who are at the greatest risk of severe COVID-19 symptoms.
Bedford doesn’t deny that his plan requires a considerable amount of work and that success is in no way guaranteed. “This is the Apollo program of our time,” he recently tweeted.
Despite all the debate over the correct approach, virtually all experts agree on one thing: That the curve has to be flattened and the number of new infections reduced to as close to zero as possible to buy time. How to proceed after that is an altogether different question, and there is a great deal of disagreement.
Essentially, there are two scenarios. The first involves loosening the measures currently in place once it becomes clear that there are sufficient intensive care beds for all those who need them. Many people would get sick, but after surviving the infection, there would also be a greater number of people with immunity.
The second is that you use all means available to prevent the spread of the virus. Few people would get infected, but you also wouldn’t make any progress in developing widespread immunity. The virus would have little difficulty in resuming its spread once measures were loosened and a high state of vigilance would have to be maintained.
The result is a dilemma for which there is currently no solution. Solving that dilemma would require knowledge about how many people have already developed immunity without knowing it. Experts believe that figure to be many times the number of confirmed cases.
Certainty can only be provided by widespread testing for the presence of antibodies in the blood — and such a test is currently being prepared in Germany. Gérard Krause, head of the Department of Epidemiology at the Helmholtz Center for Infection Research in Braunschweig, is coordinating the project. The initiative hasn’t received final approval yet, but Krause is hoping to test blood samples from more than 100,000 people beginning in April. Christian Drosten, the well-known virologist at Berlin’s Charité University Hospital, is also involved.
The idea is to repeat the test at regular intervals in order to monitor the progress of the pandemic. The result will be a much clearer picture of how far SARS-CoV-2 has already spread among the populace and how many infected people it actually kills. This would make the decision-making process easier for determining when to reopen schools or to allow major events to resume. If everything goes according to plan, the first results could be available at the end of April.
The problem with the tests currently available is that they sometimes also give a positive test result for antibodies produced in response to harmless coronaviruses for which 90 percent of adults already have antibodies. Researchers are hoping to have a more precise test procedure ready in two to three months. Then it would be possible to determine more reliably whether someone is still at risk for SARS-CoV-2 and if they could infect others or not. “Those who are immune could be issued a vaccination certificate that would allow them, for example, to be exempted from restrictions on their activities,” says epidemiologist Krause.
“An Immense Number”
Antibody tests could also help to solve the mystery of the high number of fatalities in Italy. Around 10 percent of the people with confirmed coronavirus infections in the country die. But in Germany, that figure has so far been less than 1 percent. Even if you factor in the overcrowding of hospitals in northern Italy, the difference is still astounding.
Hendrik Streeck, the director of the Institute of Virology at the University of Bonn said early on that the actual death rate in Italy is likely much lower. “I suspect there is an immense number of undetected infections,” he says. “Because it’s only patients who come to the hospitals with severe cases who are tested. A disproportionate number of those people wind up dying.” If that’s true, then Italy may well soon reach the peak of its suffering in the foreseeable future.
Is shutting down public life entirely without having access to better data the appropriate measure? Epidemiologist John Ioannidis of Stanford University has criticized the current regime of measures. He argues “the draconian measures of shutting everything down are a blind response. It is a sort of medicine that belongs to the Middle Ages.”
Of course, he too sees no other alternative in the beginning. But he does believe that it is absolutely imperative to clarify how truly dangerous COVID-19 really is. He argues that the best way to do so would be to monitor a random, representative sample of the population over an extended period of time. He says it’s even conceivable that, in the end, the virus won’t be much more dangerous than a bad flu. But only when we know for sure, he argues, will it be possible to apply the appropriate precautionary measures — until a vaccine is finally ready.
The scientific community is now working on many fronts simultaneously. Right now, it is just beginning to carry out basic research into the virus, but there is considerable haste to get an effective vaccine ready as quickly as possible. And there’s no question that this is an enormous task. Holden Thorp, the editor-in-chief of the trade journal Science, doesn’t believe all this can be managed in the foreseeable future. He compares the challenge to trying to repair an airplane that is already in flight. “This is not just fixing a plane while it’s flying – it’s fixing a plane that’s flying while its blueprints are still being drawn,” he recently wrote
In any case, the great experiment currently in place to fight the pandemic is likely to only find success if it can be corrected as needed. From a scientific point of view, adjustments must be as controlled and transparent as possible. Otherwise, we will learn nothing from them.
Virologist Streeck in Bonn says he hasn’t been pleased with the recent confusion over the measures imposed across Germany. He would also have preferred to wait and see how far the country could have gone without a shutdown. “If you keep adopting new measures each day,” the researcher says, “then we never see what is or isn’t actually useful.”