Winter is coming: What’s next in COVID-19 testing

The upcoming flu season in the Northern Hemisphere is expected to increase demand for COVID-19 testing. Decision makers may ask: Will there be enough flexible testing capacity to respond to global demand and avoid second lockdowns?

Sufficient testing capacity is widely recognized as critical to managing COVID-19 and minimizing further outbreaks, as noted by the World Health Organization. Testing enables the quick identification, management, and isolation of COVID-19 patients. As a result, many countries have prioritized COVID-19 testing in the last six months and have increased it by orders of magnitude.


Yet stakeholders around the globe are now preparing for an even larger challenge. With the onset of the winter and accompanying 2020–21 flu season, the demand for COVID-19 testing might increase threefold over the testing that has been performed in the summer months of 2020 (Exhibit 1), whether we see a second wave of virus infection or not.

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Countries still have time to prepare for this increase in demand. However, they will have to expend substantial effort and agility, with a large amount of flexibility, to prepare for all possible scenarios that might arise in the winter months.

We identify two focus areas for countries and their governments to prepare their test capacity for the winter:

  1. Scaling up testing capacity
  2. Organizing for success

The importance of sufficient test capacity

As we discussed in “Safeguarding our lives and our livelihoods: The imperative of our time,” an effective COVID-19 strategy includes containing outbreaks, protecting high-risk groups, safeguarding vital parts of the economy, and—if required—providing a sense of security and comfort. This strategy sounds simple, but is surprisingly complex to implement. Luckily, stakeholders can learn to handle all aspects from practices around the world (Exhibit 2).

Containing outbreaks

It is imperative to effectively and efficiently identify micro-outbreaks early. To do so requires a testing capacity and contact-tracing infrastructure that could be rapidly applied to a single region. Examples of success in testing/contact tracing include slaughterhouses in Germany, 1 a shopping mall in the Netherlands, 2 and a nightclub in South Korea. 3 When a large number of visitors, employees, or people in these particular communities contracted COVID-19, extensive testing of visitors and employees was used to isolate positive cases and thereby curb further infections.

Protecting high-risk groups

Highly vulnerable groups and groups of people that are highly exposed to the virus require additional focus and support. Long-term care facilities or care homes could consider the regular testing of residents and staff, including those who are asymptomatic. In Denmark, additional and regular testing of nursing home personnel and residents proved highly successful in containing outbreaks of COVID-19. 4

Employing additional safety precautions for essential workers

Essential workers have a valuable role in society—from giving people access to food and healthcare to ensuring the economy can run. Regular and asymptomatic testing would provide an extra safety barrier for those workers. Examples include successful testing of public transport officials and supermarket personnel in parts of the United Kingdom and United States, and isolation of positive cases.

Basing policy decisions on facts

If an outbreak causes paralysis in society or the economy, sometimes testing large parts of the asymptomatic population can help to rebuild trust. Widespread testing also provides the data on which to base policy decisions. Examples include China’s widespread testing in Wuhan and Luxembourg’s population-wide sampling.

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One conclusion that arises from this comparison is that all testing goals require fast results and widespread availability to ramp up capacity quickly. Not surprisingly, these two requirements are possible only if testing capacity exceeds demand. Given that we expect to see a sharp increase in demand 5 in winter, it is essential countries come up with a way to scale up capacity quickly and avoid having to restrict testing.

The next challenge: Winter is coming

In winter, demand for tests in the Northern Hemisphere is expected to increase drastically. Counterintuitively, COVID-19 incidence itself is not expected to be the main driver of the need for increased COVID testing. Rather, the most significant factor is the recurring increase of other respiratory diseases and influenza-like symptoms in the colder winter months. These illnesses historically have had much larger penetration in the population, even when compared with COVID-19 at its peak.

The peak incidence of flu-like symptoms in a population is, on average, three times higher in the winter than in the spring (Exhibit 1). 6 Since COVID-19 and the flu present with similar symptoms, more suspected “symptomatic cases” will require a COVID-19 test. With increased concern about a second wave, we also see many people in Europe who wanted to get tested with lighter symptoms. Moreover, as people grow concerned about their flu-like symptoms, a non-positive test on COVID-19 might still require further polymerase chain reaction (PCR) testing—either to reaffirm that it is not COVID-19 or to identify what virus is present.

A key challenge in predicting the demand for testing lies in the fact that the peak of the annual influenza outbreak differs from year to year. This year, the public health restrictions countries apply to contain COVID-19 also may cause a significantly decreased spread of the flu. For example, Australia saw a six-fold decrease in flu from January until June, their winter months, when the tightest lockdown measures were in place, admittedly from a high base year. 7

In the peak flu year of 2017–18, flu-like symptoms were more than five times higher in the winter than in the spring. 8 Simply put: in the upcoming flu season, it is not known when the peak will hit or how high it could go. Some Northern Hemisphere countries could be hit while they are still fighting to contain the first wave of COVID-19. Decision makers may want to consider a strategy to prepare for a wide variety of possible peaks that takes these factors into account.

1. Scaling-up testing capacity

Over the past several months, laboratories and other players in the diagnostic chain have shown dedication and resilience to scale up their capacity. The increase in capacity, however, was mostly linear, including adding more machines, materials, or people. This scale up was frequently accomplished by working late hours or deprioritizing other diagnostics—which are quick fixes, rather than sustainable solutions. As we discussed “Understanding and managing the hidden health crisis of COVID-19 in Europe,” health systems across Europe canceled or postponed tens of thousands of elective procedures and outpatient appointments in spring 2020.

Countries are challenged to create exponential growth in testing capacity, while simultaneously refraining from putting unsustainable pressure on the regular diagnostics. We describe four opportunities below to meet this challenge: improvements in productivity, the use of sample pooling, the use of multiplexing, and the adoption of creative testing methods.

Productivity improvements

Various manufacturing industries operate at significantly higher Overall Equipment Effectiveness (OEE) than medical labs. By distilling best practices from other industries, medical labs could improve productivity substantially and decrease workload for their people. Potential improvement areas include optimizing machine-run schedules with working hours, more careful planning to fully load sample plates (to avoid waste of materials), better ergonomics, and increasing machine utilization through further automation, in particular of pre-analytical work.

Experience shows that even if productivity improvements are well known, realizing them requires capabilities that are uncommon in many labs. On top of that, medical labs currently involved in COVID-19 testing often have challenges finding the right professionals. Labs could consider changing culture and behaviors in their organizations while ensuring the additional COVID-19 demand does not interfere with (or is not hampered by) regular processes. These labs also are working on maintaining the highest quality, while under extreme pressure caused by the crisis.

Sample pooling

Sample pooling is the practice of combining samples from multiple patients in one tube and treating it as a single sample during the testing process (Exhibit 3). If the test turns out negative (no COVID-19), all patients are diagnosed negative. If the test is positive, all samples need to be retested individually (leading to additional use of supplies and machine capacity). The efficiency gain is therefore dependent on the positive test rate of the patients and the pooling batch size.

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As an example, Germany currently has a positive test rate of less than 2 percent. 9 Using a pooling batch size of 7 or 8 would lead to almost four times the effectiveness of current capacity, with a small sacrifice in sensitivity (which experts note is not clinically significant).

Pooling is considered to be one of the safest ways to increase testing capacity rapidly. To implement pooling successfully, stakeholders could consider focusing on a limited set of larger labs that are used to processing high volumes with automated capabilities and, ideally, with pooling experience.


Multiplex testing allows one patient sample to be tested for multiple indications at the same time (for example, a combination influenza flu A and B virus, respiratory syncytial virus, COVID-19). Especially with the upcoming flu season, multiplexing could be important: it can take away the confusion of a COVID-19 or influenza diagnosis with one test and thus allow labs to process more tests in a given period. However, it does require machine capacity and specific assay.

Innovative testing methods

New tests could truly transform the diagnostic landscape. A variety of options exists that could be dramatically easier, faster, and cheaper to administer. The highly sensitive PCR test is seen worldwide as the gold standard. However, it is also relatively expensive and virtually all versions require a lab.

Other tests with different characteristics are under development. A much cheaper test (perhaps slightly less sensitive but still preferably with very few false negatives) would provide widespread screening and catch asymptomatic or pre-symptomatic patients. A non-lab-driven test could make tests accessible in many more locations. In a clinical setting, the overall sensitivity and accuracy of PCR would still be preferred. This means that additional communication and stratified testing methods should be used for different populations—which would introduce complexity.

Opening economies could depend not only on the availability of testing, but also on quick results indicating whether a person is contagious or not. Public health testing and lower sensitivity could get equally good results if applied in very high frequency, as in daily testing. This kind of testing would require easily available, fast, and extremely inexpensive tests.

It is worth noting, however, that in a clinical setting the overall sensitivity and accuracy of PCR would still be preferred. This preference means that additional communication and stratified testing methods should be used for different populations, although doing so introduces complexity.

Such testing methods are rapidly being developed. These methods include the use of saliva instead of a respiratory swab, isothermal amplification instead of PCR (for example, in the loop-mediated isothermal amplification [LAMP] protocol), and antigen instead of genetic tests. There also is the hope for a paper strip-based test, as well as methods based on Raman-spectroscopy, breath, and more. 10 11

Governments may choose to take an active role in introducing these technologies to the market. Potential support models include access to testing samples, accelerated certification trajectories, upfront investments, and even operational coordination across academia, labs, developers, and industrial suppliers and, potentially, in investment across borders. Some testing technologies have been proven in the lab, but will require an extraordinary investment to make them available at industrial scale in the course of months rather than years. These tests could make a major difference in limiting the virus spread this winter when vaccines will not be widely available. New tests could fill that period of time.

2. Organizing for success

To successfully organize increased capacity, strong governance is key. Currently, in many countries, the roles and responsibilities along the diagnostic chain are highly fragmented, which means central coordination is truly cumbersome in times of (peak) crisis. We see the following ways to organize for success.

End-to-end transparency

Create a holistic overview of key performance indicators (Exhibit 4) that show the relationships in the diagnostic chain from the moment a person is infected until the last possible moment an infection can occur.

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Dedicated operational control

Build a nerve center to centrally coordinate the end-to-end testing process (Exhibit 5).

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Clear roles and responsibilities. Make sure that roles and responsibilities are clear along the diagnostic chain—and that the variety of parties can be held accountable. This accountability is needed to decrease the risk of responsibilities falling between the cracks when pressure is put on the system.

Aligned financial incentives

Create a strategy for financial compensation of COVID-19 testing. Although compensation depends on the country’s specific regulatory and financing systems, some common considerations exist. Typically, labs are compensated on a per-test basis. However, in the run up to the winter, labs are asked to ramp up their capacity in anticipation of an uncertain demand. Therefore, compensation schemes with fair risk-sharing should be created. For example, one could compensate a lab for having capacity ready, in the same way firefighters are compensated—not by the number of fires they extinguish, but by their ready capacity to do so.

Early investments in innovation

Stakeholders may want to evaluate how innovative testing methods take time to develop and validate. It is challenging to speed up this process at will or fully at risk. Therefore, early decision making and technological investments by governments or government consortia are crucial to create the opportunity for the long-term impact that can stem from these innovations.

The first wave of COVID-19 has taught us that responding to the crisis early and decisively acting is essential. Winter is coming, and it is increasingly clear that testing can help us unlock our lives and our economies faster and more confidently. Therefore, we expect that investments in innovations—to ensure both an intelligent testing strategy and a strong governance system—are vital.

The lessons we have learned from the past months can help guide us—and support our ability to mitigate, or even prevent, a second wave.

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