On-off social distancing may be needed until 2022 — Harvard study
Commuters wearing face masks sit on a train at the Atocha Station in Madrid on April 13, 2020 as some companies were set to resume operations at the end of a two-weeks halt of all non-essential activity amid a national lockdown to stop the spread of the COVID-19 coronavirus. The death toll from the coronavirus pandemic has slowed in some of the worst-hit countries, with Spain readying to reopen parts of its economy as governments grapple with a once-in-a-century recession.
AFP/Javier Soriano
On-off social distancing may be needed until 2022 — Harvard study
Issam Ahmed (Agence France-Presse) - April 15, 2020 - 8:45am

WASHINGTON, United States — A one-time lockdown won't halt the novel coronavirus and repeated periods of social distancing may be required into 2022 to prevent hospitals from being overwhelmed, Harvard scientists who modeled the pandemic's trajectory said Tuesday.

Their study comes as the US enters the peak of its COVID-19 caseload and states eye an eventual easing of tough lockdown measures.

The Harvard team's computer simulation, which was published in a paper in the journal Science, assumed that COVID-19 will become seasonal, like closely related coronaviruses that cause the common cold, with higher transmission rates in colder months.

But much remains unknown, including the level of immunity acquired by previous infection and how long it lasts, the authors said.

"We found that one-time social distancing measures are likely to be insufficient to maintain the incidence of SARS-CoV-2 within  the limits of critical care capacity in the United States," lead author Stephen Kissler said in a call with reporters. 

"What seems to be necessary in the absence of other sorts of treatments are intermittent social distancing periods," he added.

Widespread viral testing would be required in order to determine when the thresholds to re-trigger distancing are crossed, said the authors.

The duration and intensity of lockdowns can be relaxed as treatments and vaccines become available. But in their absence, on and then off distancing would give hospitals time to increase critical care capacity to cater for the surge in cases that would occur when the measures are eased.

"By permitting periods of transmission that reach higher prevalence than otherwise would be possible, they allow an accelerated acquisition of herd immunity," said co-author Marc Lipsitch.

Conversely, too much social distancing without respite can be a bad thing. Under one modeled scenario "the social distancing was so effective that virtually no population immunity is built," the paper said, hence the need for an intermittent approach.

The authors acknowledged a major drawback in their model is how little we currently know about how strong a previously infected person's immunity is and how long it lasts.

Virus likely here to stay

At present the best guesses based on closely-related coronaviruses are that it will confer some immunity, for up to about a year. There might also be some cross-protective immunity against COVID-19 if a person is infected by a common cold-causing betacoronavirus.

One thing however is almost certain: the virus is here to stay. The team said it was highly unlikely that immunity will be strong enough and last long enough that COVID-19 will die out after an initial wave, as was the case with the SARS outbreak of 2002-2003.

Antibody tests that have just entered the market and look for whether a person has been previously infected will be crucial in answering these vital questions about immunity, they argued, and a vaccine remains the ultimate weapon.

Outside experts praised the paper even as they emphasized how much remained unknown.

"This is an excellent study that uses mathematical models to explore the dynamics of COVID-19 over a period of several years, in contrast to previously published studies that have focused on the coming weeks or months," Mark Woolhouse, an infectious disease epidemiologist at the University of Edinburgh said.

"It is important to recognize that it is a model; it is consistent with current data but is nonetheless based on a series of assumptions -- for example about acquired immunity -- that are yet to be confirmed."

NOVEL CORONAVIRUS SOCIAL DISTANCING
As It Happens
LATEST UPDATE: November 26, 2020 - 5:37pm

Follow this page for updates on a mysterious pneumonia outbreak that has struck dozens of people in China.

November 26, 2020 - 5:37pm

Russia on Thursday registered record numbers for daily infections and deaths from the coronavirus for the second time in less than a week. 

Health officials reported 25,487 new infections, bringing the national total to 2,187,990 cases since the beginning of the pandemic — the fifth-highest caseload in the world.

Health authorities also reported 524 deaths, raising Russia's total fatalities from COVID-19 to 38,062. — AFP

November 26, 2020 - 2:14pm

South Korea reported its highest daily number of coronavirus cases since March on Thursday, with a surge of new infections sparking fears of a major third wave.

Officials announced 583 new cases after several weeks of fresh infections ranging between around 100 and 300.

The latest cases have mostly been clusters at offices, schools, gyms and small gatherings in the greater Seoul area, the Korea Disease Control and Prevention Agency said.

New infections also emerged within the military, including dozens of newly enlisted soldiers at a boot camp — prompting the defense ministry to bolster its virus measures. — AFP

November 26, 2020 - 1:29pm

South Korea reported its highest daily number of coronavirus cases since March on Thursday, with a surge of new infections sparking fears of a major third wave.

Officials announced 583 new cases after several weeks of fresh infections ranging between around 100 and 300.

The latest cases have mostly been clusters at offices, schools, gyms and small gatherings in the greater Seoul area, the Korea Disease Control and Prevention Agency said. — AFP

November 26, 2020 - 8:31am

The coronavirus pandemic is no excuse for not getting enough exercise, the World Health Organization says Wednesday, warning that even before the crisis many were getting too little physical activity. 

In an update of its physical activity guidelines, the UN health agency stressed that exercise was vital to physical and mental health, while sedentary behaviour can have serious repercussions.

"WHO urges everyone to continue to stay active through the Covid-19 pandemic," the agency's head of health promotion Ruediger Krech told reporters.

"If we do not remain active, we run the risk of creating another pandemic of ill-health as a result of sedentary behavior." — AFP

November 25, 2020 - 8:29pm

The coronavirus crisis has hit Italy's already historically-low birth rate, new projections from the national statistics agency reveal. 

Italy had last year already recorded its lowest number of births for 150 years, at 420,000, but this could fall to 408,000 in 2020 and 393,000 in 2021, according to Istat.

The projections were presented by Istat chief, Gian Carlo Blangiardo, to lawmakers on Tuesday.

"The climate of fear and uncertainty as well as financial difficulties... caused by recent events will have a negative effect on the fertility of Italian couples," he said. — AFP

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