Can You Diagnose COVID-19 From a Cough?

November 11, 2020



As we and many others in the field have recorded, COVID-19 poses a more serious risk to people with underlying health conditions and chronic illnesses, such as diabetes. The numbers are alarming – a Lancet Diabetes & Endocrinology study mining 61 million medical records in the United Kingdom reported that 30% of COVID-19 deaths occurred among people with diabetes.


Prevention and good diabetes care are the leading tactics to protect people with diabetes by controlling their blood sugar through diet, exercise, monitoring, and medication. But many don’t feel safe exercising outdoors although they know staying active and maintaining good blood sugar levels may be their best defense against COVID-19. Getting the virus under control is essential for them as it is for all of us.


Some very good news came out this week with the announcement of a vaccine candidate developed by Pfizer and BioNTech that is more than 90% effective in preventing COVID-19. The vaccine has been tested on 43,500 people in six countries and no serious safety concerns have been raised. It’s expected that up to 50 million doses of the vaccine will be produced by the end of the year and up to 1.3 billion doses in 2021. There are still questions to be answered, e.g. how long does immunity last, and how to deal with the significant manufacturing and logistical challenges in immunizing huge numbers of people around the world? But the announcement of the new vaccine has been warmly welcomed around the world with some suggesting life could be back to normal by spring. Let’s hope!


Another piece of exciting – if lower profile – news in the last few weeks is innovative technology developed at MIT that could accurately diagnose COVID 19 from your cough. This AI model distinguishes asymptomatic people who are infected with COVID-19 from healthy individuals through forced-cough recordings, which people voluntarily submit through cellphones and laptops.


The researchers trained the model on tens of thousands of samples of coughs, as well as spoken words. When they fed the model new cough recordings, it accurately identified 98.5 percent of coughs from people who were confirmed to have COVID-19, including 100 percent of coughs from asymptomatic people who reported they did not have symptoms but had tested positive for the virus.


The MIT team is working on incorporating the model into a user-friendly app, which if FDA-approved and adopted on a large scale, could be a free, convenient, non-invasive prescreening tool to identify people who are likely to be asymptomatic for COVID-19. A user could log in daily, cough into their phone, and instantly get information on whether they might be infected and therefore should confirm with a formal test. This diagnostic tool could diminish the spread of the pandemic if everyone uses it before going to a classroom, a factory, shop or a restaurant. The research team envisions their AI tool as a low-cost COVID-19 pre-screener that could be deployed in settings where comprehensive diagnostic testing is unavailable or unable to scale for entire populations. So, until the new vaccine is readily available worldwide, this novel technology will complement ongoing efforts to halt the spread of a still vicious Coronavirus.

Why COVID-19 Reinfections Are a Particular Concern For Diabetics

October 15, 2020



COVID-19 continues to spread and severely impact the world. People of all ages are being infected but as we have covered before, people with diabetes seem to be more vulnerable to becoming severely ill as the virus can be harder to treat due to fluctuations in blood glucose levels and, possibly, the presence of diabetes complications. We are all waiting for a COVID-19 vaccine so that things can get back to normal. Meanwhile, the emphasis will continue to be on handwashing, social distancing and wearing face masks.


Those precautions are not only for the ones who have managed to escape the virus so far. Recent studies have confirmed at least five reinfection cases in as many countries. In a previous blog, we discussed COVID-19 immunity and if it was possible to get it twice. Now it seems that the answer is “Yes” even if it may be extremely rare and more research is required to fully understand the possibility of reinfection.


In one of the recent studies on a confirmed case of COVID-19 reinfection in the United States, researchers found evidence that an individual with no known immune disorders or underlying conditions was infected with COVID-19 in two separate occurrences. The patient who is a 25-year old male was infected with two distinct COVID-19 variants within a 48-day timeframe, while testing negative in between infections. After experiencing severe COVID-19 symptoms again, including fever, headache, dizziness, cough, nausea, and diarrhea, the patient was hospitalized and tested positive a second time. According to the researchers, the patient’s second infection was more severe, resulting in hospitalization with oxygen support. The patient has since been discharged from the hospital and has recovered from the second infection.


Several hypotheses have been put forward to try to explain the severity of the second infection. One is the possibility that the patient, after having been infected for the first time, encountered a very high dose of the virus which caused a more acute reaction the second time. Another hypothesis is that the patient may have come in contact with a more virulent version of the virus.


In the view of the researchers, the five reinfection cases indicate that previous exposure to COVID-19 may not translate to guaranteed total immunity. But further research into reinfections is required. According to one of the lead researchers, Dr. Pandori, we need a more profound understanding on how long immunity may last for people exposed to COVID-19 and why some of these second infections, while rare, turn out to be more severe. In light of this, the researchers strongly suggest that individuals who have already been infected with COVID-19 continue to take serious precautions when it comes to the virus with emphasis on handwashing, social distancing and wearing masks.

How RetinaRisk Can Help During COVID-19

October 1, 2020



The COVID-19 crisis is having a dramatic impact everywhere. The death toll has now crossed 1 million and the outbreak seems to be still on the rise. The impact on global eye healthcare is considerable mainly due to travel restrictions and reprioritization of health resources. Ophthalmologists in many countries are concerned that, due to COVID-19, patients are skipping crucial appointments for eye treatment, potentially resulting in thousands and even millions going blind unnecessarily. Also, due to lockdown, eye screening of millions is being delayed resulting in enormous backlogs in many places when life gets back to normal.


The clinically validated RetinaRisk algorithm can help in various ways during these challenging COVID-19 times by empowering people living with diabetes to monitor their risk of sight-threatening diabetic retinopathy and by streamlining and personalizing eye care based on risk prediction.


How does it work? The RetinaRisk algorithm calculates the individualized risk for persons living with diabetes of developing sight-threatening eye disease, based on key risk factors, namely gender, type and duration of diabetes, retinopathy diagnosis, HbA1c and blood pressure.


How can RetinaRisk help?


Prioritization during lockdown – RetinaRisk can assist hospitals and healthcare providers to determine which patients need to attend eye screening and seek treatment during lockdown situations and who can safely stay home. The RetinaRisk API (Application Programming Interface), is a system-to-system solution, that allows hospitals, clinics and healthcare providers to identify high-risk patients who need immediate care to prevent vision loss and low-risk patients whose eye screening appointments can safely be postponed.


Dealing with eye screening backlogs – when things get back to normal, RetinaRisk offers a scientific approach for calling in high-risk patients for priority eye screening when dealing with the large backlogs.  By stratifying and recommending variable intervals for eye screening, based on patient’s risk profile, RetinaRisk increases the clinical safety of patients while making diabetic retinopathy eye screening more efficient and cost-effective.


Patients can monitor their risk at home – RetinaRisk app empowers people living with diabetes to assess and monitor their risk of developing sight-threatening diabetic retinopathy despite halted services and seek timely medical assistance if needed. It also indicates which are the key risk factors for each calculation – blood pressure or blood sugar levels – and offers extensive educational material on how to lower these modifiable risk factors.  The app allows patients to better understand their condition and motivates them towards enhanced diabetes care. The users can set their goals as regards blood sugar and blood pressure, monitor progression and share with healthcare providers. Logging eye screening appointments and other new features will be introduced later this year.


The RetinaRisk algorithm is based on extensive international research and has been clinically validated in over 25.000 diabetic patients in five countries.The results have been published in peer-reviewed scientific articles in respected medical journals.


RetinaRisk is focused on wellness, prevention and personalization through digital engagement and predictive analytics. We’re witnessing the rise of digital health and fundamental changes in healthcare with patients becoming more knowledgeable and active participants in their wellness journey. With the RetinaRisk app, we are raising awareness about diabetes and the risk of eye disease that could lead to blindness. We’re providing patients with information that helps them manage their diabetes care and related health decisions. RetinaRisk offers a truly personalized approach leading to the right patient receiving the right treatment at the right time. For more information about RetinaRisk please visit our website here.

Tough but True: COVID-19 Lockdowns Resulted in Increased Diabetic Amputations

September 15, 2020


Diabetic foot syndrome is one of the serious consequences of long-term uncontrolled diabetes, due to a mix of peripheral neuropathy and micro-vasculopathy in the lower extremities. “Diabetic foot” is defined as infection, ulceration or destruction of tissues of the foot associated with neuropathy or peripheral artery disease in the lower extremity of a person with diabetes. It may vary from minor ulceration to necrosis of tissues, sometimes requiring amputation. Of all the late complications of diabetes, those involving the foot have traditionally required more face-to-face patient visits to clinics to treat wounds by debridement, offloading, and many other treatment modalities.


The COVID-19 pandemic, which continues to spread worldwide, has resulted in health care systems facing tough challenges in delivering diabetic foot service to patients. In many cases, public health guidelines and the risk of virus transmission, have led to reconfiguration of methods to support and manage diabetic foot patients, including remote consultations. The outbreak has in some cases led to the suspension of routine clinical work as all healthcare resources are mobilized to fight the pandemic.


A recent study shows that patients with diabetes admitted to a tertiary care center for diabetic foot ulceration during the COVID-19 lockdown in Italy had a more than threefold risk for amputation, versus patients seen in 2019. The study compared 25 patients who were admitted from March 9 to May 18, 2020, with 38 patients who were admitted from a longer period between January and May 2019. The results reveal high numbers of emergent and serious cases in 2020. According to the team, the COVID-19 lockdown seemed to have a detrimental impact on amputation risk because of the sudden interruption of diabetic foot ulcer care resulting in delayed diagnosis and treatment. The higher risk of amputation observed during COVID-19 lockdown confirms the need for proper and timely management of diabetic foot ulcer patients to prevent dramatic outcomes responsible for a reduction of quality of life and increased morbidity and mortality.


In the United Kingdom, guidance for clinicians on how to prevent lower limb amputation during the COVID-19 situation targets the identification and management of people with critical/limb-threatening ischaemia or infection. The basic premise of the document is that is essential to recognise foot and leg complications that are limb- or life-threatening and refer them for urgent multidisciplinary care.


Recent evaluation of the guidelines emphasizes the need to preserve the positive elements of diabetic and high-risk foot and lower-limb care that have been facilitated by the pandemic, including enhanced local system working, professional networking and technology-enabled service delivery options, such as digital consultations. These innovative ways of working together have greatly aided communication and collaboration between patient, community and hospital and need to be preserved in this next phase of care. It seems that the structure, function and delivery of diabetes and high-risk foot services will be changed for the better as we move forward through the COVID-19 pandemic.


During a pandemic, it’s understandable that inpatient care should focus on those with severe cases of the infection However, it’s clear that patients with diabetic foot ulcer need to be carefully protected to reduce the risk of COVID-19. But these people can’t be left without clinical care. It´s likely that many of the recently introduced guidance or changes in the management of people with diabetic foot ulcer will become the new normal in our approach to those with this common clinical problem.

What Are the Long-Term Health Issues of COVID-19 For Diabetics?

September 8, 2020


Most people who have COVID-19 recover completely within a few weeks, but older people and those with serious medical conditions are the most likely to experience lingering COVID-19 symptoms. It can damage lungs and many other organs (i.e., liver and kidneys) and increase the risk of long-term health problems. Data from the COVID Symptom Study suggest that 10% to 15% of people who get infected develop persistent symptoms and don´t recover quickly.


The most common symptoms identified by the Mayo Clinic include fatigue, cough, shortness of breath, headache and joint pain. COVID-19 can also make blood cells more likely to form clots; much of the heart damage caused by the virus is believed to stem from small clots that block the capillaries there. COVID-19 can also weaken blood vessels, which can contribute to potentially long-lasting problems in several organs


It’s becoming increasingly clear that people with diabetes face a higher chance of experiencing serious complications from COVID-19. Generally, the more health conditions someone has, the higher their chance of getting serious complications from the novel virus.


Your risk of getting sick from COVID-19 is likely to be lower if your diabetes is well-managed. When people with diabetes do not manage their diabetes well and experience fluctuating blood sugars, they are generally at risk for many diabetes-related complications. Having heart disease or other complications in addition to diabetes could worsen the chance of getting seriously ill from COVID-19, like other viral infections, because your body’s ability to fight off an infection is compromised.


It’s not all gloomy news: people with diabetes learn to take over the job of an organ, and this trains them to pay attention to their bodies more intently, understand cause and effect, and react to changes. Take for example the compelling story of Cynthia Katsingris, a US mother of two, who has lived with type 1 diabetes for 30 years and recovered from COVID-19.


Cynthia went from being utterly terrified of catching COVID-19 to testing positive for the virus. Her realization that she was positive was replaced with an unshakable determination to fight the virus. She said: “People with diabetes strive for mastery of how food, sleep, stress, illness, and so many other factors affect the body and its blood sugar levels – and I could use that to my advantage.”


Cynthia voraciously read scientific papers about the virus and was able to break the situation into unemotional parts and focus intently, as with diabetes, on the parts she could control, like what are the obstacles, what helps remove the obstacles, and what supports a return to health. She used her continuous glucose monitor (CGM) to avoid possible incorrect blood glucose readings due to tissue compression while she was spending all day in bed. She took vitamins and supplements to stop viral replication, boost immune function, assist cellular function, and support the lungs. But foremost, Cynthia focused on what people with diabetes are already very aware of – that what we eat matters, our mindset matters, and being proactive matters.


As we said up front, most people with COVID-19 recover quickly. But the potentially long-lasting problems from the virus make it critical to reduce the spread of the disease by following precautions such as wearing masks, avoiding crowds, and keeping hands clean.

Why Diabetes Eye Care is At Risk Due to COVID-19

August 13, 2020


The Coronavirus has impacted the lives of almost everyone in the world and especially those living with diabetes as the disease has been identified as a risk factor for severe symptoms of COVID-19. Indeed, recent US studies have revealed that nearly 40% of COVID-19 victims had diabetes and that half of the people aged under 65 who died with coronavirus had diabetes.


The coronavirus crisis has also in many cases severely impacted routine treatment and care of people with diabetes. A recent study by the World Health Organization (WHO) has shown the partial or complete interruption of health services for people with non-communicative diseases, including a 49% slash in diabetes care. In more than 90% of countries, healthcare workers have been partially or fully reassigned to frontline pandemic duties. Restrictions related to the coronavirus lockdown also resulted in the cancelation of many regular health appointments, including diabetic eye screening.


The majority of the over 460 million people living with diabetes around the world are at risk of developing diabetes-related eye disease that could lead to blindness. But with early diagnosis and prompt treatment, serious eye damage can be prevented. This is why the American Diabetes Association is launching a new multiyear initiative designed to raise awareness and suggest actions for those at risk of developing sight-threatening diabetes-related eye disease.


Regular eye screening of people living with diabetes is vital. The purpose of the routine appointment is to look for signs of diabetic retinopathy – a disease that affects the fine blood vessels in the retina at the back of the eye. Diabetic retinal screening is different from most other types of screening appointments as its purpose is to prevent the development of complications in patients who already have diabetes, while most other types of screening programmes aim to detect the disease in a healthy population.


Encouraging findings of the survey were that alternative strategies have been established in many countries to support the people at highest risk to continue receiving treatment for non-communicative diseases, with many adopting telemedicine and digital health solutions. These solutions include the clinically-validated RetinaRisk app, which is uniquely positioned to raise awareness about diabetic retinopathy risk and the importance of early detection.


The RetinaRisk app empowers people with diabetes to assess and monitor their individualized risk of developing sight-threatening eye disease. The forthcoming RetinaRisk API solution can also serve healthcare providers by identifying high-risk patients who need immediate medical attention and recommend appropriate eye screening interval, based on the individual’s risk score.  Our clinical and real-life studies have demonstrated that risk profiling increases the screening frequency of high-risk patients, while low-risk patients are spared from unnecessary clinical visits, without compromising clinical safety.


The RetinaRisk telemedicine solution offers a personalized approach to ensure that the right persons receives the right care at the right time in an efficient and cost-effective way. RetinaRisk can play a significant role in streamlining eye screening programs during COVID-19 times and dealing with the backlog when life gets back to normal and ensuring that those most at risk receive the treatment needed.

How Superspreader Events Impact the Spread of COVID-19

July 21, 2020


For the past six months, the Coronavirus has traversed the globe, infecting one person after another. The novel virus poses a particular threat to people living with diabetes and can even cause diabetes in otherwise healthy individuals. Early on, researchers estimated that a person carrying the Coronavirus would, on average, infect another two to three people. More recent studies indicate that this figure may actually be higher and at times be transmitted by a select few individuals or so-called “superspreaders”.


Epidemiologists describe “superspreaders” as those who infect a significantly high number of other people. In the context of COVID-19, it hasn’t been narrowed down how many infections someone needs to cause to qualify as a “superspreader”. Whether an infected person turns out to be a “superspreader” or not depends on a combination of the pathogen, individual immune systems or the distribution of virus receptors in their bodies, but mainly their environment and behavior. A person’s social behaviors, travel patterns and degree of contact with others can contribute to superspreading.


Up to 50% of all of those who get COVID-19 are asymptomatic and may continue their normal activities and inadvertently infecting more people. Even people who ultimately do show symptoms are capable of transmitting the virus during a pre-symptomatic phase.


Several recent studies have shed light on the troubling role of superspreading in COVID-19’s dispersion around the globe. Researchers in Hong Kong examined a number of disease clusters by using contact tracing to track down everyone with whom individual COVID-19 patients had interacted. In the process, they identified multiple situations where a single person was responsible for as many as six or eight new infections. The researchers estimated that just 20% of those infected with the Coronavirus were responsible for 80% of all local transmission. This means that coronavirus transmission more or less follows the 80/20 Pareto Principle (named after Italian economist Vilfredo Pareto), i.e. 80% of all consequences come from just 20% of the possible causes.


Although it isn´t possible to medically diagnose “superspreaders”, their evident impact can be limited. Contact tracing is critical for identifying potential carriers and isolating them and anyone they have been in contact with. This keeps “superspreaders” from moving around and spreading the virus. Epidemiologists also point to mitigating the “three Cs” of transmission: closed spaces with poor ventilation, crowded settings, and close contact with others.


That brings us to “Superspreader Events” – gatherings where the number of cases transmitted will be disproportionately high compared to general transmission. Events like birthday parties, bar nights, and even choir practice, seem to be the culprits in an outsized number of COVID-19 infections. It is worth keeping in mind that the risk of infection seems significantly higher in closed spaces than outdoors and indications suggest that the Coronavirus is not only transmitted via droplets and surfaces, but also by airborne transmission. This means the virus can linger in small and badly ventilated spaces in aerosol form.


Bringing together a “superspreader” and a “superspreader event” can be a deadly mix. It is therefore suggested that one avoid crowded, closed indoor spaces, especially without any sort of personal protective equipment like masks. Selecting outdoor seating and maximizing ventilation in an indoor setting may be the way to go along with limiting the number of people inside a room and continuing to keep individuals spaced apart.


Let´s all take the precautions needed to avoid becoming a “superspreader” and help controlling the novel virus that’s changing all of our lives.

Can COVID-19 Cause Diabetes?

June 23, 2020


Evidence is building up convincingly to support the theory that patients with an underlying health condition, like diabetes are far more likely to be seriously affected by COVID-19 than otherwise healthy people. According to data recently released by the Centers for Disease Control and Prevention in the United States, fewer than 2% of previously healthy people died from the infection, compared to nearly 20% with pre-existing conditions, most often heart disease, diabetes or lung disease. This is based on health data from 1.7 million coronavirus cases between January 22 and May 30 this year.


But a surprising claim is being made by a panel of 17 diabetes specialists from around the world: COVID-19 may be causing otherwise healthy individuals to develop diabetes for the first time. According to the scientists, there’s a two-way relationship between COVID-19 and diabetes that deserves our attention. On one hand, having diabetes increases the risk of severe COVID-19 symptoms. On the other, COVID-19 seems to cause new-onset diabetes and severe metabolic complications of preexisting diabetes, including diabetic ketoacidosis and hyperosmolarity for which exceptionally high doses of insulin are warranted.


Diabetes develops when the body’s ability to regulate blood glucose levels breaks down. This can be caused by damage to beta cells in the pancreas that produce the hormone insulin, known as type 1 diabetes, or from the body becoming insensitive to the hormone, which leads to type 2 diabetes.


In the past, viral infections have been linked to the first time a patient had diabetes symptoms, as viral infections may trigger the destruction of the insulin-producing islet cell “factories” in the pancreas, setting up a chronic autoimmune response. There are recorded cases of acute diabetes developing during mumps and enterovirus infections as well as significant evidence linking one particular enterovirus (Coxsackie-B1), with classical autoimmune type 1 diabetes.


The researchers also cite a case report from a hospital in Singapore of a previously healthy man who developed diabetic complications after contracting COVID-19. In addition, a 2010 study of 39 patients who were receiving treatment for severe acute respiratory syndrome (SARS) in a Chinese hospital indicated that 20 of these hospitalized patients developed diabetes for the first time.


To address these issues, an international group of leading diabetes researchers have established a global registry of patients with COVID-19–related diabetes. With the registry, they aim to establish the extent and characteristics of new-onset COVID-19 related diabetes and to investigate its pathogenesis, management, and outcomes. The scientists hope that given the short history of human contact with COVID-19, the registry will help us to better understand how COVID-19 related diabetes develops, its natural history and its best management.


There are still many questions unanswered. As Paul Zimmet, professor of diabetes at Monash University in Melbourne, Australia, and a co-lead investigator in the project said: “We don’t yet know the magnitude of new-onset diabetes in COVID-19 and if it will persist or resolve after the infection, and if so, whether or not COVID-19 increases risk of future diabetes. By establishing this global registry, we are calling on the international medical community to rapidly share relevant clinical observations that can help answer these questions.”

Why a COVID-19 Vaccine is Especially Important For Diabetics

June 3, 2020


The question on everybody´s lips since the outbreak of the Coronavirus is how long it will take to make a COVID-19 vaccine. Millions of people around the world have already been infected by the novel Coronavirus, often with devastating consequences. As we have reported in our previous blogs, people with diabetes may be more vulnerable to COVID-19 and need to take special care.  Although lockdown is slowly being eased in many countries, there are real concerns that a second wave of infections can be expected. Getting a vaccine to protect us against the coronavirus before the second wave hits is of paramount importance to save lives.


The Coronavirus spreads easily, and the majority of the world’s population is still vulnerable to it. A vaccine would provide some protection by training people’s immune systems to fight the virus. This would allow lockdowns to be lifted more safely, and social distancing to be relaxed.


Research is happening at breakneck speed. A vaccine would normally take years, if not decades, to develop. Currently there are about 80 groups around the world researching vaccines and some are now entering clinical trials. The work on a new COVID-19 vaccine is using newer, and less tested, approaches called “plug and play” vaccines. Because we know the genetic code of the Coronavirus (Sars-CoV-2), scientists have the complete blueprint for building it.


Researchers in Oxford University in the United Kingdom have put small sections of its genetic code into a harmless virus that infects chimpanzees. They hope they have developed a safe virus that looks enough like the Coronavirus to produce an immune response. Other groups are using pieces of raw genetic code (either DNA or RNA depending on the approach) which, once injected into the body, should start producing bits of viral proteins which the immune system again can learn to fight.


Most experts think a vaccine is likely to become available by mid-2021, about 12-18 months after the virus first emerged. Others are more optimistic, with some hoping to have a number of doses ready by September. But even when a vaccine is ready, the logistical challenges will be immense on a global scale. There´s a need for billions of doses and they must get to every part of the world as quickly as possible. As Bill Gates put it: “It’s going to require a global cooperative effort like the world has never seen.”


The World Health Organization (WHO) is facilitating collaboration and accelerating efforts to develop and evaluate candidate vaccines on a scale not seen before. It is convening vital communications across the research community and harnessing a broad global coalition. Over 120 vaccines have been proposed across the world and WHO is tracking details in a landscape exercise on their type and progress. WHO has used its global mandate to rapidly convene hundreds of scientists, developers and funders to increase the likelihood that one or more safe and effective vaccines will soon be available to all.


While the scientists at the University of Oxford and other research facilities are optimistic that their work will prove successful, there are no guarantees that an effective or fully-effective vaccine for COVID-19 will ever be found. But what is clear is that if they are able to produce a vaccine within the next 18 months, it would be considered one of the most remarkable pieces of scientific work in history.


Can You Catch COVID-19 Twice?

May 13, 2020


In previous blogs, we covered some guidelines regarding COVID-19 and Diabetes, including the key symptoms, the various telemedicine options and extensive advice from our endocrinologist, Dr. Arna Guðmundsdóttir. In today´s blog we will investigate if those who have caught the Coronavirus can catch it again.


Understanding how our immune systems respond to infection with COVID-19 is key to formulating an exit strategy from the 2020 pandemic. Much of the debate about how we might begin to lift restrictions has centered around the need for a proven antibody test that looks for the presence of antibodies – specific proteins made in response to infections. Antibodies can be found in the blood of those who are tested after infection and show that they have had an immune response to the infection.


Here’s the question at hand:  If we were able to tell who have been infected and have recovered, and if those people could demonstrate immunity against catching the virus again, could we begin to allow them to go back to work and otherwise engage with many people? Let’s look at some of what goes into the answer.


Antibodies are proteins produced by the immune system to target a virus, bacterium or other pathogen. They destroy the pathogen by binding to it and making it harmless, or by flagging it for destruction by immune cells. They typically linger on in the bloodstream after an infection in case the virus returns. If it does, the immune response is much faster; patients who have recovered have resistance to reinfection. Indeed, for most viruses, the first time you catch the infection your body takes time to develop the requisite antibodies, but you should be better equipped to fight off the infection a second time.


Unfortunately, it might not be as simple with COVID-19. The World Health Organisation has warned that there is no evidence that people who have recovered from COVID-19 and have antibodies are protected from a second infection. One recent paper looked at reinfection in rhesus macaques, who, after being infected with a standard dose of the virus, did not catch the infection a second time.


Dosage is important: the dose that you might receive varies depending on whether you breathed in airborne particles or, say, touched a contaminated surface and rubbed your eyes. If someone were only exposed to a small dose of the virus in the first instance, who can say how they might react if the second dose were much greater.


It’s unclear whether having a stronger dose response will leave you any better off. The hope is that recovered patients have developed enough COVID-19-specific antibodies to fight off a secondary infection. However, in one study on convalescent patients in China, 30% of those studied had very little or no detectable antibodies in their blood plasma.


The situation will undoubtedly change as new information emerges. Cities, counties, and states are rolling out widespread antibody testing to try to understand how many people have come into contact with the virus. And the further we get from initial infections, the more we’ll know about how antibody levels change over time and whether reinfection is possible.