Public health researcher Alison Barrett also reviews other policy-relevant research and reading, including why Vermont and the Cherokee Nation have been so successful in controlling COVID-19 relative to other places in the United States.
Ranking the effectiveness of worldwide COVID-19 government interventions
Haug, N et al., Nature Human Behaviour, 16 November 2020
Researchers have analysed the impact of government-implemented non-pharmaceutical interventions (NPIs) on the rate of COVID-19 transmission and found that no single solution on its own can reduce the rate of transmission. Rather, a combination of NPIs, tailored to each individual country, works best.
NPIs are used to control and manage the spread of COVID-19 in the absence of medical treatments or a vaccine. They include measures such as travel restrictions, border closures, physical distancing, personal protective measures, banning mass gatherings and self-isolation.
How countries have used NPIs varies greatly. Because of the large societal and economic effects of NPIs, it is important to know which ones are the most effective and efficient in preventing outbreaks while having minimal impact on society.
Curfews, lockdowns, restrictions on gatherings, school closures and individual movement restrictions were found to be the most effective.
However, it is a challenge to specifically assess the effectiveness of individual NPIs as they are often implemented concurrently. These measures are also very disruptive to society, causing interruptions to education and necessary medical treatments, increased domestic violence and financial burden, among other things.
Effective risk communication strategies are vital and considered to have less disruptive consequences. Governments need to actively communicate COVID-19 prevention messages to the public, promoting physical distancing and travel warnings to the public.
Haug and colleagues wrote,“surprisingly, communicating on the importance of social distancing has been only marginally less effective than imposing distancing measures by law” – highlighting the effectiveness of good communication. Risk communication must be specifically tailored to individual groups, to ensure the message is accessible and understood.
The least effective interventions include environmental cleaning and disinfection and increasing quarantine and isolation facilities.
In summary, the authors suggest that a combination of NPIs tailored to individual countries and contexts, implemented at the optimal time with effective risk communication, is the best strategy for minimising the spread of COVID-19.
Virology, transmission and pathogenesis of SARS-CoV-2: Clinical update
Cevik, M et al., BMJ, 23 October 2020
In the year since the first case of COVID-19 was identified, exceptional advances have been made in understanding the virus. This review provides an update on knowledge of the incubation period, transmission routes and immune response of SARS-CoV-2, the virus that causes COVID-19.
SARS-CoV-2 is a beta coronavirus, similar to SARS-CoV-1, which resulted in an epidemic in 2002-2004. SARS-CoV-2 is far more infectious than SARS-CoV-1 as it is an upper respiratory tract disease, rather than a lower respiratory tract disease like SARS-CoV-1.
Duration of infectious period
The incubation period – the time after a patient has been exposed with the virus to the time they develop symptoms – is usually five to six days. This is also the period of the highest viral load (the amount of infectious virus in a person) in the upper respiratory tract, and highest infectious period.
It is most likely that symptomatic and pre-symptomatic (one to two days before symptoms appear) transmission of SARS-CoV-2 play the largest role in spreading the virus.
Because of the possibility of asymptomatic and pre-symptomatic transmission, and the short time frame from being exposed to being infectious, early identification of COVID-19 cases is a challenge and highlights the importance for continued preventive measures such as physical distancing, testing, contact tracing and self-isolation.
The most widely used test to identify SARS-CoV-2 in Australia is the reverse transcription polymerase chain reaction (RT-PCR) test, where a swab collects a nasal and throat sample.
Most symptoms are mild and resemble typical influenza symptoms, including fever, cough, malaise, headache, myalgia, and loss of taste and smell. More severe symptoms include pneumonia, breathlessness and need for ventilation.
Evidence is emerging about the long-term consequences of the virus, with many patients reporting persistent symptoms lasting weeks or months.
SARS-CoV-2 is primarily transmitted by infected respiratory droplets, when an infected person coughs, sneezes or talks, usually within close contact (1.5-2 metres).
Airborne transmission of aerosols, micro particles of the virus, that can accumulate indoors and remain infectious for long periods of time is another way in which the virus is transmitted. Areas of poor ventilation can intensify aerosol transmission.
SARS-CoV-2 can also be transmitted by virus particles on surfaces, called fomite transmission. The virus particles can remain on smooth surfaces for many days; however, SARS-CoV-2 is easily inactivated by disinfectants, highlighting the importance of cleaning surfaces regularly and maintaining thorough handwashing hygiene.
Phases of illness
There tends to be two phases of the illness once the virus has entered the body.
First is a viral response, where the SARS-CoV-2 binds to a host cell, angiotensin-converting enzyme 2 (ACE2), and then is released in the lungs. This action causes symptoms including fever, muscle pain, headache and respiratory symptoms. In some patients, the virus also causes damage to the cells in the nasal cavity which may be the cause for the loss of taste and smell. The ACE2 receptor is found in other organs, which may explain why the virus causes gastrointestinal and cardiovascular symptoms.
The second phase is the immune response, when virus-specific immune cells (T-cells) are activated to the site of infection and kill the infected cells before the virus spreads.
Most patients recover in this phase. However, in some people, SARS-CoV-2 causes an abnormal immune response, severely damaging lung tissue and other organs. It is unclear why, but this reaction may be caused by an overproduction of function regulation cells (cytokines) that build up in the lungs.
Antibodies, proteins that identify and protect from foreign substances in the body, can be detected in the patient in the first four days of illness; however, they tend to develop gradually and most patients have detectable antibodies after four weeks. It is unclear how long the antibodies remain.
Severity of the disease is associated with being an older age, male and having pre-existing medical conditions, including hypertension, heart disease, diabetes, chronic obstructive pulmonary disease, obesity and malignancy.
While a lot has been identified and learnt about the novel coronavirus, many questions remain. It is unclear why some patients develop severe symptoms from the virus and others do not; and further understanding of the biological mechanism of SARS-CoV-2 and bodies’ immune response will help in therapeutic and vaccine development.
In conclusion, the authors wrote: “We need optimal testing systems and technologies to support and inform early detection and clinical management of infection. Greater understanding is needed regarding the long-term consequences following acute illness and multisystem inflammatory disease, especially in children.”
Five rules for evidence communication
Blastland, M et al., Nature, 18 November 2020
To communicate science, researchers have traditionally been advised to be persuasive, engaging and tell a story, rather than report the full details of the research neutrally, potentially damaging trustworthiness and credibility.
Authors of this commentary, from the University of Cambridge, UK, collect data on issues about best ways to communicate uncertainty, how audiences decide what to trust and “how narratives affect people’s decision-making”.
“Our aim is to design communications that do not lead people to a particular decision, but help them to understand what is known about a topic and to make up their own minds on the basis of that evidence. In our view, it is important to be clear about motivations, present data fully and clearly, and share sources.”
The authors propose an evidence-based communication approach:
Inform, not persuade
The authors suggest that traditional science communication techniques work best when the main aim is to change behaviour or beliefs. However, some of their research has found that people are sensitive to the perceived aims of communicators and scientists who are perceived to prioritise persuasion may lose trust.
In communicating science, scientists and/or researchers need to be open about their motivations, limitations and conflicts of interests; they “cannot expect to be trusted on the basis of expertise alone,” the authors wrote.
Offer balance, not false balance
In informing evidence, it is important to communicate the balance of all relevant evidence. Each individual has their own psychological biases and stored beliefs, which means it can be difficult to accept evidence that is contrary to their what they believe they know.
One potential reason that evidence is partially presented is because communicators argue that people can’t absorb a lot of information at once. However, if found to underplay evidence or not share the full story, “motivations – and hence our trustworthiness – will be questioned”.
The authors recommend presenting science communication in a table representing pros and cons, or projected benefits and harms. “For your audience, knowing what the pros and cons are is crucial,” they say.
It is also important for science communicators to share what is not known.
“The simplest argument for stating uncertainty is that what we think we know is constantly changing.” The wearing of face masks is an example of this.
The authors recommend saying:
- What you know
- What you don’t know
- What you are doing to find out
- What people can do in the meantime to be cautious, and
- That advice will likely change.
The New Zealand Ministry of Health’s website on COVID-19 provides a good example of describing uncertainties, such as those surrounding likelihood of false negative COVID-19 tests.
State evidence quality
“As scientists, we tend to underestimate the sophistication of our audiences’ sensitivity to cues of quality and how these affect trust.”
When communicating science, it is important to discuss the quality of evidence, including the size and source of data. Be as specific as possible with details (without being too complicated) so that the audience can judge quality and relevance to them.
Inoculate against misinformation
Some communicators may worry that disclosing uncertainties, complexities in study designs, or unwelcome possibilities may lead to people distorting their message.
However, the authors wrote that, “research on climate change, COVID-19 and other topics shows that if people are pre-emptively warned against attempts to sow doubt (known as pre-bunking), they resist being swayed by misinformation or disinformation.”
To do this, communicators need to understand the concerns of the audience and anticipate any potential misunderstandings.
The authors recommend considering what the audiences are deciding and what information (and in what format) would be best to support the decisions. For example, in the context of climate change, research has found that public perception of expert consensus increases if the large scientific agreement about human-caused climate change is communicated, especially in conjunction with warnings about political attempts to spread misinformation. This helps protect public perceptions about the scientific consensus.
In conclusion, the authors wrote:
Trust is crucial.
Always aiming to ‘sell the science’ doesn’t help the scientific process or the scientific community in the long run, just as it doesn’t help people (patients, the public or policymakers) to make informed decisions in the short term.
That requires good evidence communication.”
World Economic Outlook, October 2020: A Long and Difficult Ascent
International Monetary Fund (IMF), October 2020
In October, the IMF published a report on the world’s economic outlook.
In brief, the report discusses the economic impact of the extended pandemic after many countries hesitantly reopened in May and June, and that while uncertainty remains, the global economy is slowly rebuilding with the projected forecast for 2021 looking better than it did in June.
The detailed report can be read here.
Ed Yong, a science journalist for The Atlantic, recently shared a thread of recommended pandemic-related pieces from other writers in the United States.
Articles he shared include:
Quote from the piece: “The Cherokee Nation, it seems, may have lessons for us all. “I hope our response as a nation demonstrates what being in a tribe means,” Pivec, senior director of public health for Cherokee Nation Health Services, said. “It’s collectively caring for one another.”
Quote from the piece: “So, what’s the key to Vermont’s success? It’s pretty simple, Sosin said. Instead of just talking about how ‘social distancing is a privilege’, leaders in the state designed programs and policies to overcome barriers to social distancing.”
‘Iowa’s COVID wave and the limits of personal responsibility’ by Megan Molteni
Quote from the piece: “It wasn’t laws and fines that Iowa needed,” said Republican Iowan governor, Kim Reynolds, “but for its citizens to ‘step up and take personal responsibility’.” For months, she pushed this message of self-determination. And while the sun was shining, and people were spending time outdoors, it looked like it was working.
Quote from the piece: “We have reasons to celebrate, but—and you knew there was a ‘but’—a devastating surge is now under way. And worse, we are entering this dreadful period without the kind of leadership or preparation we need, and with baseline numbers that will make it difficult to avoid a dramatic rise in hospitalizations, deaths, and potential long-term effects on survivors.”
The full thread and recommendations can be found here: https://twitter.com/edyong209/status/1330530458434723840?s=20
Alison Barrett is a Masters by Research candidate and research assistant at University of South Australia, with interests in public health, rural health and health inequities. Follow on Twitter: @AlisonSBarrett. Croakey thanks her for providing this column as a probono service to our readers.
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