- Explained: Types of human coronaviruses
- A shot of hope with a game changing vaccine
- India must adopt plans that avert the worst-case scenario
EXPLAINED: TYPES OF HUMAN CORONAVIRUSES
Focus: GS-III Science and Technology
What are coronaviruses?
- Coronaviruses are a large family of single-stranded RNA viruses that cause diseases in animals and humans.
- In humans, the viruses usually cause mild to moderate upper-respiratory tract illnesses such as the common cold.
- In the last two decades, more aggressive coronaviruses have emerged that are capable of causing serious illness and even death in humans. These include SARS-CoV, MERS and now SARS-CoV-2.
- Human coronaviruses were first characterised in the mid-1960s and they are mostly considered to be responsible for causing upper respiratory tract infections in children.
- In animals, coronaviruses can cause diarrhoea in cows and pigs and upper respiratory tract disease in chickens.
- These viruses are named “Coronaviruses” because of spikes found on their surface that give them the appearance of a crown when looked through an electron microscope.
- Broadly, coronaviruses (CoV) are the largest group of viruses that belong to the Nidovirales order, which includes Coronaviridae among three others. Coronavirinae are one of the two subfamilies of Coronaviridea, with the other being Torovirinae. Coronavirinae can be further subdivided into alpha, beta, gamma and delta coronaviruses.
- While there are hundreds of coronaviruses, there are seven that we know can infect humans.
- Out of the seven, two are alpha coronaviruses (229E and NL63) and four are beta coronaviruses (OC43, HKU1, MERS and SARS-CoV).
- The classification of the viruses is based on their phylogeny, which is to say it reflects how these virus strains evolved from their common ancestors.
- Alternatively, coronaviruses may be classified based on serology (monitoring the immune system’s antibody response to viral exposure) as per which they can be divided into three groups from I to III. Groups I and II refer to mammalian coronaviruses and Group III includes avian coronaviruses.
When the human coronaviruses were first identified?
- One of the first coronaviruses strains to be described in the mid-60s.
- OC43 was Discovered in 1967 according to the Journal of Virology.
- NL63 and HKU1 was First identified in the Netherlands in 2004.
- SARS-CoV was identified 2003 in China (animal source not yet known, bats thought to have given it to other animals, probably civet cats).
- MERS was discovered 2012 in Saudi Arabia (transmitted by dromedary camels)
- SARS-CoV-2 has emerged 2019 in Wuhan (source not yet known, possibly bats).
What are the symptoms they cause?
Before SARS-CoV-2 and MERS, SARS-CoV was the first example of a human coronavirus that could cause serious illness in humans in the form of severe acute respiratory syndrome. Other human coronaviruses such as OC43 and 229E are known to cause the common cold, whereas NL63 is associated with serious respiratory symptoms such as upper respiratory tract infection and pneumonia.
A SHOT OF HOPE WITH A GAME CHANGING VACCINE
Focus: GS-III Science and Technology
Gravity of the situation
- Over the initial phase of the national lockdown (March 24 to April 14), India reported a 20-fold increase in confirmed SARS-CoV-2/COVID-19 cases (468 to >10,000), and a 36-fold increase in deaths (9 to 330).
- Increased testing may partly account for this; but testing is still inadequate and this data represent underestimates.
- The case-fatality of 2% to 3% is indicative of the large number of deaths India can expect.
- The failures in widespread testing for infection or for immunity imply that transmission-chains via asymptomatic, mildly-symptomatic and pre-symptomatic people remain undetected.
- The lockdown (an extreme example of mitigation) has been extended to May 3.
- The dire socio-economic consequences and the scale of human tragedy that play out daily make a prolonged total lockdown undesirable.
- Alongside infection-control, a strategic plan of action to mitigate suffering and to stimulate economic recovery is urgently needed.
What is a social vaccine?
- A social vaccine is a metaphor for a series of social and behavioural measures that governments can use to raise public consciousness about unhealthy situations through social mobilisation.
- Social mobilisation can empower populations to resist unhealthy practices, increase resilience, and foster advocacy for change.
- When applied to pandemics, the effectiveness of a social vaccine is determined by the extent of dissemination and uptake of accurate information about personal infection risk and methods to reduce the risk through consistent core messages disseminated through a variety of means.
Lesson from HIV pandemic’s Serious Issues
- The human immunodeficiency virus (HIV) that causes the acquired immune deficiency syndrome (AIDS) is believed to have made the zoonotic jump from monkeys through chimpanzees to humans in Africa as early as the 1920s, but the HIV/AIDS epidemic was detected in 1981 and was a pandemic by 1985.
- The early years of the HIV/AIDS pandemic were also a time of global panic. The cause was unknown (till 1984) and diagnostic tests were unavailable (till 1985). Since there was no treatment, a diagnosis of HIV infection was a death sentence.
- Widespread fears of contagion rendered many infected people homeless and unemployed. Many were denied access to care.
- Stigma, discrimination and violence towards infected individuals, their families, social groups (sex-workers, gay men, drug users, truck drivers, migrants), and even health workers, were common.
- Criminalising sex-work and injecting drug use followed
- Conspiracy theories, misinformation and unproven remedies were widely propagated.
- The blame game targeted world leaders and international agencies.
- The preparedness of health systems, societal prejudices and socio-economic inequities were starkly exposed.
How was the HIV pandemic handled?
- Reducing HIV transmission centred on acknowledging that everybody was potentially infected — even those apparently healthy — and that infection occurred predominantly through sexual transmission and intravenous drug use.
- The core preventive messages involved being faithful to one sexual partner or 100% condom use during sexual intercourse outside stable relationships; resisting peer-pressure for risky behaviours, and harm reduction for intravenous drug use.
- These measures conflicted with prevailing cultural, social, religious, behavioural and legal norms.
- These strategies and advocacy against stigma and discrimination were successfully adapted in India.
- These skills and experiences can be innovatively adapted for the current pandemic.
How it can work?
- The core infection-control messages are available from official sources. Maintaining physical distancing in social situations (unless impossible) and wearing cloth masks or facial coverings in public (especially where distancing is impossible) by 100% of people (and 100% of the time) is key to preventing infection along with regular disinfection of oneself and one’s surroundings.
- Effective and innovative IEC and SBCC strategies should address the barriers and facilitators to implementation.
- People are more likely to practise these behaviours if all leaders (without exception) promote them publicly and consistently, the whole community believes in their importance, and if proper information, support, and materials are available and accessible.
- Coercive or punitive methods are invariably counter-productive, as was seen with HIV/AIDS.
INDIA MUST ADOPT PLANS THAT AVERT THE WORST-CASE SCENARIO
Focus: GS-III Science and Technology
Forecast of a Contraction in Economy
- Forecasting the sharpest contraction in world output since the Great Depression of the 1930s, the IMF slashed its projection by 6.3 percentage points from its January forecast for 3.3% growth to a 3% decline. In contrast, the recession of 2009 saw world output contract by a mere 0.1%.
- In projecting an annual expansion in Asia’s largest economy, the fund is rather optimistically foreseeing a sharp rebound in activity over the rest of the year.
Forecast for India
- On India, the IMF has cut its projection for growth in the fiscal year that started on April 1, from January’s 5.8%, to 1.9%.
- This again appears predicated on the fund’s baseline scenario that assumes that the pandemic would ‘fade in the second half of 2020’, allowing containment efforts to be unwound and economic activity to normalise.
- Another key assumption by the IMF’s economists is the availability of policy support to nurture the revival once activity restarts.
- India’s fiscal measures pale in terms of scale when compared with what several other nations have undertaken.
- Given the size of the informal sector in India as well as the anticipated prolonged disruption in labour supply even in more formal parts of the economy, the Centre needs to proactively commit to a substantial stimulus package in order to ensure that once the economy reopens, it has the legs to run.