Coronavirus – the science: Will Covid-19 die this summer?

This is part of a series of regular updates from Irish Times Environment and Science Editor Kevin O’Sullivan who is examaining scientific initiatives and developments on coronavirus. Part one can be found here

‘When will it end?’

The horrible aspect of the Covid-19 pandemic is nobody knows when it will it end. It begs difficult questions: Will it return like seasonal flu? Will it be killed off by summer conditions?

Empty, mocked-up shells of SARS-CoV-2 (the medical term for the virus), may help explain how well the virus stands up to heat, humidity and other environmental changes, say physicists at the University of Utah.

They want to understand how it reacts as seasons change, notably whether summer will do anything to slow spread.

“Coronavirus spreads similarly to the influenza virus, as small mucus droplets suspended in the air. Viruses lose infectivity because the particles lose structural integrity,” explained University of Utah physicist Saveez Saffarian.

“The physics of how the droplets evolve in different temperature and humidity conditions affect how infectious it is.”

Scientists are evaluating how the virus’s protective outer shell responds under different conditions. Viruses are not able to do anything on their own, as they are simply shells with genetic instructions tucked inside; when a virus invades a host’s cells, it uses that cell’s machinery to replicate itself, over and over again.

The researchers are working with dummy versions of the virus’s protective outer shell. Using the sequenced genetic make-up of Covid-19, they are building synthetic versions of these shells with no viral genomes inside, which are uninfectious. “We’re making a faithful replica of the virus packaging that holds everything together,” his colleague Michael Vershinin said. “The idea is to figure out what makes this virus fall apart, what makes it tick, what makes it die.”

They hope to find out how well the virus will transmit in different conditions, from outdoors in summer heat to indoors in air-conditioned offices. This could influence how long social distancing and lockdown policies will need to be in place.

CovidWatch latest

The daily posting from #CovidWatch, courtesy of Prof Liam Glynn of UL and Dr Mike O’Callghan remains the best summary of Irish trends, complete with pithy public health advice.

For Friday it reads: “Cases are increasing (in part due to more testing) but now more than ever we have to cocoon our elderly and stay in our family units. #Lockdown may be needed sooner than later.”

The case for lockdown is getting more support throughout the scientific community, on the basis that after several weeks of it, authorities can identify infected people through contact tracing and isolate them and their contacts to prevent further infections.

“After a few weeks of lockdown almost all infectious people are identified and their contacts are isolated prior to symptoms and cannot infect others,” according to US physicist Dr Yaneer Bar-Yam, expert in the social challenges associated with pandemics.

“If someone develops symptoms, the people with them can be isolated. So including these cases and a few random ones, it takes four to five weeks to stop the outbreak. China and South Korea showed this actually works,” he declared.

The most chilling prediction

The single most stark scientific indicator of the wrecking ball that’s going to hit was the results of modelling by a team at Imperial College London.

It predicted a massive overload of hospitals and many deaths; 250,000 in the UK, 2.2 million in the US. It was so shocking the research was distributed widely before publication in a scientific journal, and sent to the White House over the weekend.

It prompted many countries to scale-up their restrictions. Some scientists have since challenged some of its conclusions, notably the finding “large scale social distancing will need to be in place for many months, perhaps until a vaccine becomes available”.

They contend this is wrong – including a finding that resurgent outbreaks are likely – as it did not factor in the benefits of lockdown and contact tracing sufficiently. There is, however, no dissenting voice on its essential conclusion, the need to scale up restrictions rapidly and move to lockdown.

One of the UK government’s top coronavirus experts Prof Neil Ferguson was centrally involved. He had to self-isolate in his central London flat after developing coronavirus symptoms and revealed he was probably infectious when he attended a Downing Street press conference on Tuesday – yet another indication of Covid-19’s infectivity

He tweeted: “Sigh. Developed a slight dry but persistent cough yesterday and self-isolated even though I felt fine. Then developed high fever at 4am today. There is a lot of Covid-19 in Westminster.”

Grounds for optimism

- China reports no domestic cases for the second day in a row after a two-month lockdown.

- ”If a country does a good job with testing and ‘shut down’, then within 6-10 weeks they should see very few cases and be able to open back up.” The prediction of billionaire and philanthropist Bill Gates. He knows something about pandemics having warned repeatedly one was overdue in the form a flu or novel coronavirus – lots of social isolation and lockdown needed in meantime.

- Medical authorities in China indicate the Japanese drug favipiravir used to treat flu (developed by a Fujifilm subsidiary), “has a high degree of safety and is clearly effective in treatment” for coronavirus.

@KOSullivanIT