The coronavirus outbreak challenge

The World Health Organization (WHO) is closely monitoring an outbreak of a respiratory illness caused by a novel (new) coronavirus (CoV) that was first detected in Wuhan City, Hubei Province of China in December 2019 and which continues to expand.

Coronaviruses are a large family of viruses found in both animals and humans. A novel coronavirus is a new strain of coronavirus that has not been previously identified in humans. The novel coronavirus, now called 2019-nCoV, had not been previously detected before the outbreak was reported in Wuhan.

2019-nCoV is a beta coronavirus, like other corona viruses SARS (Severe Acute Respiratory Syndrome) and MERS (Middle East Respiratory Syndrome), all of which have their origins in animals, SARS-CoV from civet cats to humans in China in 2002 and MERS-CoV from dromedary camels to humans in Saudi Arabia in 2012. Coronaviruses are a large family of viruses that are common in many different species of animals, including camels, cattle, cats, and bats. Several known coronaviruses are circulating in animals that have not yet infected humans. As surveillance improves around the world, more coronaviruses are likely to be identified. Rarely, animal coronaviruses can infect people and then spread between people such as with MERS and SARS, and now with 2019-nCoV.

Early on, many of the patients in the outbreak of respiratory illness caused by 2019-nCoV in Wuhan, had some link to a large seafood and live animal market, suggesting animal-to-person spread. Later, a growing number of patients reportedly did not have exposure to animal markets, confirming the person-to-person spread. Analysis of the genetic tree of this virus is ongoing to know the specific source of the virus and public health officials and partners are working hard to identify the source of the 2019-nCoV. Chinese officials report that sustained person-to-person spread in the community is occurring in China and health officials have reported thousands of infections with 2019-nCoV, with the virus reportedly spreading from person-to-person in many parts of that country, most of them associated with travel from Wuhan. People living or travelling in an area where the 2019-nCoV virus is circulating may be at risk of infection. At present, 2019-nCoV is circulating in China where the vast majority of people infected have been reported but person-to-person spread has been reported outside China . These infected people from other countries are among ones who have recently travelled from China or who have been living or working closely with those travellers, such as family members, co-workers or medical professionals caring for a patient before they knew the patient was infected with 2019-nCoV. With the growing number of Chinese cases and international locations outside China it is possible to estimate the virus’s contagiousness, which is captured in a variable called R0. A figure around 3 for R0 has been calculated meaning that every person who caught the disease would give it to 3 other people but this one is still to be considered with caution since that there is still considerable uncertainty associated with the outbreak.

The new coronavirus is a respiratory virus which spreads primarily through contact with an infected person through respiratory droplets generated when a person, for example, coughs or sneezes, or through droplets of saliva or discharge from the nose. Both SARS and MERS have been known to cause severe illness in people. The complete clinical picture with regard to 2019-nCoV is not fully understood. Reported illnesses have ranged from infected people with common cold symptoms including a runny nose, sore throat, cough, and fever to people presenting more severe condition including pneumonia or breathing difficulties and the disease can be fatal, but as of to-day the mortality rate appears lower than the one observed with SARS and MERS. Older people, and people with pre-existing medical conditions (such as, diabetes and heart disease) appear to be more vulnerable to becoming severely ill with the virus.

Outbreaks of novel virus infections among people are always of public health concern. The risk from these outbreaks depends on characteristics of the virus, including whether and how well it spreads between people, the severity of resulting illness, and the medical or other measures available to control the impact of the virus (for example, vaccine or treatment medications) and finally the way it can mutate . The fact that this virus has caused severe illness and sustained person-to-person spread in China is concerning, but it’s unclear how the situation will unfold at this time.

The incubation period is the time between infection and the onset of clinical symptoms of disease. Current estimates of the incubation period range from 1-12.5 days with median estimates of 5-6 days. These estimates will be refined as more data become available. Based on information from other coronavirus diseases, such as SARS, and MERS, the incubation period of 2019-nCoV could be up to 14 days. WHO recommends that the follow-up of contacts of confirmed cases is 14 days.

To date, there is no specific medicine recommended to prevent or treat the novel coronavirus. However, those infected with 2019-nCoV should receive appropriate care to relieve and treat symptoms, and those with severe illness should receive optimized intensive care. Some specific treatments are under investigation and will be tested through clinical trials.

There is therefore an urgent need to get a vaccine since the humans have never been exposed to this virus. WHO is coordinating urgently several expert consultations that will feed into an international research and innovation forum (planned in February 2020). This forum will ensure a transparent process that engages a broad group of policy makers, researchers, public health experts, non governmental organizations, funders, and the private sector. Crucially, the consultation will engage researchers from affected countries to set priorities that respond to country needs, and that reduce barriers and maximize opportunities for research at national level.

Work has begun at multiple organizations, to develop a vaccine for this new strain 2019-nCoV of coronavirus are just getting started working. Their vaccine development strategy will benefit both from work that has been done on closely related viruses, such as SARS and MERS, as well as advances that have been made in vaccine technologies, such as nucleic acid vaccines, which are DNA- and RNA-based vaccines that produce the vaccine antigen in the human body. This work involves designing the vaccine constructs - for example, producing the right target antigens, viral proteins that are targeted by the immune system, followed by testing in animal models to show that they are protective and safe. Once safety and efficacy are established, vaccines can advance into clinical trials in humans. If the vaccines induce the expected immune response and protection and are found safe, they can be mass produced for vaccination of the population but the vaccine development and registration will likely take months.

WHO explains that the world needs an emergency mechanism to coordinate all the different stakeholders in global research and development (R&D), from academics and industry to national governments, civil society groups, and non-governmental organizations. That mechanism already exists: the R&D Blueprint2 Global Coordination Mechanism (GCM) which is a voluntary framework to facilitate information sharing and incentivize funders, product developers, and researchers to share evidence about candidate vaccines, therapeutics, and diagnostics in the pipeline that could be brought to bear against 2019 nCoV. Such a coordination is essential to make sure that any gaps in the research agenda are filled, and any duplication of effort is avoided. The GCM has been activated.

These massive and urgent efforts are based upon the risk assessment made by WHO, graded very high for China, high at the regional level, and high at the global level with the following factors taken into consideration:

• Likelihood of further spread: Human-to-human transmission, including
  transmission within families and healthcare settings, confirmed
  within Wuhan, and in several cities outside China. The outbreak
  continues to grow within China at a rapid rate. Ordinarily high
  volumes of domestic and international travel have been increased
  further by travel linked to Lunar New Year celebrations. Imported
  cases continue to be reported internationally, with several reported
  cases of secondary transmission now confirmed in countries outside of
  China. Limited testing capacity in many countries globally,
  non-specific symptoms of 2019 nCoV acute respiratory disease (the
  disease caused by 2019 nCoV infection), and co-circulation of other
  respiratory pathogens are factors that can complicate efforts to
  detect the virus quickly.

• Potential impact on human health: The virus can cause severe illness
  and death, although most cases appear to be mild. However, many
  uncertainties remain, including the full extent of the current
  outbreak within China, and the full clinical spectrum of illness,
  including the prevalence of mildly symptomatic cases.

• Effectiveness of current preparedness and response measures: China
  has dedicated substantial resources to public health control measures
  and clinical management and has taken action that has included the
  quarantine of cities, and the widespread suspension of transport
  links between population centres. It will be important to continually
  assess the extent to which measures are effective and the need to
  adapt measures as the situation evolves. Up to now, countries that
  have reported an imported case have demonstrated efficient and
  effective disease surveillance and response measures.

In the current stressful period caution must be brought to dissemination of rumours, misconceptions, and misinformation online via social media which can have a negative impact on response measures and health-seeking behaviours and which have to be fought through a concrete and not overly alarmist communication able to preserve public health and limit potential severe social and economic consequences.

This underlines the global need of a reinforced worldwide coordination and cooperation between various public and private stakeholders to overcome efficiently this challenging outbreak because of significant remaining question marks.