Second wave of pandemic avoidable
Key lies in curbing spread of virus through restrictions, experts say
History shows that pandemics have second waves, but scientists say it’s not inevitable in B.C., where the COVID -19 outbreak is currently under control.
A lot depends on whether eased physical distancing restrictions will continue to curb the deadly coronavirus. It will also depend on whether the province can keep a handle on cluster transmissions through testing, contact tracing and isolation.
The 1918 Spanish flu pandemic — and subsequent smaller influenza outbreaks in the 1950s, 1960s and 2000s — all included waves of infections.
Although flu viruses and the novel coronavirus cause respiratory illness, and there are other similarities between viruses, they don’t behave exactly the same. For example, flu viruses are more prevalent in the fall and winter months.
“I don’t see the big second wave as inevitable,” says University of B.C. epidemiologist Daniel Coombs.
The potential for a second wave — whether in the near term as a result of recent eased restrictions, or in the fall-winter period — is tied to whether provincial measures are adequate to keep the virus from spreading, said Coombs.
“I think the province would step in before we had a big second wave,” he said.
Coombs was referring to the possibility that restrictions such as limiting restaurants to takeout only, lifted in the third week of May, could be reintroduced if infections and hospitalizations spiked.
Coombs added there is a possibility of continued clusters of transmission. Those have already happened in B.C. long-term care homes, prisons and poultry plants. Other places that had the virus under control such as Singapore have seen outbreaks in dormitories that house foreign workers.
Simon Fraser University epidemiologist Caroline Colijn noted the virus has not “naturally” gone away and might come back in the fall.
She said the only reason the spread of the virus was halted is because of extraordinary public health measures enacted in midMarch. Those included closing schools and universities and shutting personal-service shops such as hair salons.
Public health officials also made a major push to encourage people to keep two metres away from others not in their households and established similar guidelines for grocery stores and pharmacies that stayed open.
Beginning in the third week of May, restrictions were eased, allowing personal-service businesses to reopen.
Restaurants and pubs were also allowed to restart seated dining with physical distancing restrictions.
Colijn said the question is whether the remaining restrictions will be enough to keep cases under control.
“But we don’t really know. So, in that sense, I wouldn’t say it was inevitable,” she said.
Coombs added there’s a question of what happens in the fall when children return to school.
A small-scale return is planned for June, but a full return to school isn’t scheduled until September.
There is some uncertainty about the role that children play in transmission of the virus, but more information will be provided by the experience of schools in places such as Europe, he said.
That information could help develop strategies for the fall, Coombs said.
Provincial health officer Dr. Bonnie Henry has said she doesn’t believe a resurgence in the virus right now is inevitable if British Columbians continue to follow physical distancing measures.
Henry has said, however, she believes the province does need to plan for a second wave in the fall because history shows pandemics have had a second, seasonally related wave in the fall.
University of Victoria history professor Mitch Hammond says viral outbreaks have come in waves, sometimes as many as three, including the 2009 H1N1 pandemic.
“But it’s hard to know what’s going to happen with this coronavirus, it’s a bit of uncharted territory,” said Hammond, who specializes in the history of epidemic diseases and authored Epidemics and the Modern World, released this year.
He said a U.S. study of 40 communities’ effectiveness in responding to the 1918 Spanish flu pandemic found factors that resulted in greater success. Those included earlier lockdowns and collaboration across different levels of government.
Governments today have an advantage because there is scientific evidence of how viruses work and more sophisticated public health and communication tools.
“That enables us to have a very elegant message: We need to flatten the curve,” he said.
Although the coronavirus is different than the polio virus, the fight against polio also offers some helpful insights, Hammond said.
The virus came in waves in the summers from 1916 onward, with the most serious occurring in the 1940s and 1950s.
The outbreaks were highly regional and local, and when cases reached a certain threshold it resulted in schools being closed and children being kept away from, for example, swimming pools and movie theatres. Parents also restricted children’s interactions with each other, Hammond said.
The distancing measures for polio aren’t unlike those in place now in B.C., and were used intermittently until a vaccine was created, he said.