Medical advances may shorten COVID-19 duration

The coronavirus that emerged from China is heading towards becoming a pandemic

World Health Organisation (WHO) Director General Tedros Adhanom Ghebreyesus yesterday said that Coronavirus Disease 2019 (COVID-19), which originated in Wuhan, "has pandemic potential." COVID-19 is accelerating towards a pandemic, but scientific promptness and efficient communication between countries is acting as a brake. This is the third recorded animal-to-human transmission of a coronavirus, after SARS (2002) and MERS (2012).

What next

The virus will spread through asymptomatic individuals, and contact tracing may be too late to prevent an impending pandemic, even if it is not officially declared one. Countries are actively testing and managing those infected, but numbers can quickly rise, especially in states with weak governance, dense populations or poor healthcare systems. However, early genome sequencing of the virus and the quick development of diagnostic tools mean that efforts to find a treatment and vaccine have begun with unprecedented speed. They may not bear results immediately, but could shorten the duration of the outbreak and save many lives.

Subsidiary Impacts

  • Restrictions on the Chinese workforce and expenditure on the disease will be detrimental to the economy, at least in the short term.
  • Open and accessible clinical and scientific data sharing will become pivotal towards global preparedness.
  • Mass and social media will need a more coordinated strategy to curb the spread of misinformation among the public and avoid creating panic.

Analysis

The initial cross-species transmission of the virus SARS-CoV-2 was found in early December. The novel pneumonic disease it causes, COVID-19, linked to a wet market in the Chinese city of Wuhan, was spotted in late December. The first death from COVID-19 occurred on January 11 this year.

Parallels were drawn immediately to the 2003 SARS outbreak which had infected some 8,000 people with 10% fatality, contributing to initial panic. SARS-CoV-2 has spread much faster, infecting more than 80,000 people. It is, however, important to note that around 20% of patients experience severe disease requiring hospitalisation and the mortality rate is 2-3%, much lower than SARS and MERS.

Despite initial missteps from Chinese authorities that probably gave the virus time to start an epidemic (see CHINA: COVID-19 outbreak will weaken Xi - February 27, 2020), the virus was isolated, sequenced and scientific and clinical data openly shared in less than two weeks -- an impressive emergency response by scientists. The first sequencing was available by January 9 and officially published on January 23. This triggered a concerted research effort to develop diagnostics, identify vaccine targets and establish the epidemiology and evolution of the virus.

Progress has been made in a matter of weeks in developing diagnostics compared, for example, to SARS, when it took about six months to develop diagnostics (although that was also in part due to China not alerting the world early enough).

A pandemic?

SARS-Cov-2 is a respiratory virus that spreads primarily through coughing, sneezing and fomites (objects carrying infectious material such as doorknobs). Such infections are particularly difficult to curb, especially in busy cities with a high population density and active travel networks. The majority of infected individuals will show only mild symptoms, which may lead to missed infections and sustained spread of the virus, especially during flu season in many parts of the world.

Recent fatalities from Italy, South Korea and Iran indicate a latent spread of infection being driven by individuals who are getting diagnosed too late or not at all but can transmit the virus to vulnerable victims.

Even with temperature screening and preparedness measures across the world, the virus has spread to 53 countries in less than two months. So far, hospitals are coping, but may become overwhelmed if the numbers of severely ill patients grow. The effectiveness of contact tracing may also begin to diminish if cases are diagnosed very late and by then secondary and tertiary waves of infection have occurred.

Weaker health systems in areas with political instability, sub-optimal hygiene control and high population density may become critical epicentres of the disease. A mitigating factor might be that some countries have experience battling daunting viruses, such as Ebola, so they have diagnostic labs, local capacity and the WHO and Center for Disease Control and Prevention are present.

COVID-19 is spreading fast, but a declaration of pandemic has high costs

The WHO has not yet declared an official pandemic -- a worldwide spread of a new disease that is self-sustaining in other regions (eg, through second or third waves of local spread outside China) without having a direct link to travel or infection at source (China). There are no defined categorical thresholds for declaring one.

It would be costly for countries to deploy pandemic measures if they are not needed, and also trigger panic (see INTERNATIONAL: Coronavirus to hit early 2020 world GDP - February 10, 2020). The last declared pandemic was H1N1 in 2009. At the time, the WHO was criticized for declaring a pandemic, since it subsided reasonably quickly and may have induced unnecessary costs. There is still hope that COVID-19 may be countered with isolation and hygiene.

Treatments?

Early and open scientific data-sharing for SARS-CoV-2 facilitated the designing of rapid diagnostics (which is possibly the most important step), and also enabled research into the functional biology of the virus for potential drug targets.

Currently, more than 80 treatment trials are listed in China, including synthetic drugs, traditional Chinese medicine, stem cell therapy and antibody therapy. Only some of these may be pursued to ensure rigorous and robust testing with sufficient control arms and systematic clinical parameters. The majority of drugs are existing antivirals developed against other viruses such as Ebola and HIV.

Two of these appear to be ahead of the others: Remdesivir (being tested in a phase III human trial of 760 patients) and Favilavir (recently approved by the National Medical Products Administration of China after showing effectiveness in treating 70 patients). An effective treatment to cure patients will be found soon, but a vaccine to make the population refractive to the virus will take several months to develop, even though the first trials have begun.

Is this the last of them?

This is probably not the last novel coronavirus; many more are bound to emerge in different parts of the world in time. Theoretical estimates as to the total diversity of viruses that can potentially infect humans show that fewer than 2.5% of them are known. It is only a matter time before an event like this happens again. Just like HIV, Ebola and SARS, all came from exposure to an animal in which these viruses normally reside.

The medical community has become much better at early diagnosis

However, the medical community is much better at diagnosing infections early, and has shown increased commitment to fast-paced research in the event of outbreaks, as well as fast-tracked clinical trials for drugs as well as vaccines (as was also seen in the use of a vaccine early during the Ebola outbreak in the Democratic Republic of the Congo). Genome sequencing technology is now available and affordable across the world. Every continent is capable of locally sequencing an outbreak to find out what is causing it. Once the first step is accomplished and data shared, anyone across the world who has an idea or has been working in that area can contribute.

Even with the best of health systems, infectious disease management is highly resource dependent, and countries with the poorest healthcare may be the weakest link in any worldwide outbreak, especially with increasing connectivity and travel. Animal-to-human contact may be impossible to negate, especially when human activities are continually encroaching on natural habitats and disturbing ecosystems. In this instance, for example, shutting down the wet market may not be the solution, but regulation and surveillance may be a better long-term investment.