In 1918, the second wave of the Spanish flu was the most deadly. During the H1N1 pandemic in 2009, most of Quebec had been infected in the fall than in the spring. Should we worry about a second wave of COVID-19, in a few months ? Not necessarily, say experts.
“In September 1918, it was mostly soldiers and it was a virus that affected young adults, there was a peak very sharply at the age of 28,” says Alain Gagnon, professor of demography at the University of Montreal and a specialist in pandemic caused by the flu.
Regarding the 2009 pandemic, the school had acted as a place “amplification of the virus,” according to the balance sheet of the epidemiological of the Institut national de santé publique du Québec (INSPQ).
Common Point of the two pandemics : the two viruses were of the H1N1 flu virus.
However, the coronavirus is different. “The risk of being infected seems to be lower in children, but there are many questions about their role in the transmission, this is a group for which one is in a situation very unusual,” says Gaston De Serres, an epidemiologist at the INSPQ.
In addition, in 2009, the cities of Montreal and Laval had been affected during the first wave, and then the following autumn it was the turn of the regions.
This time, even though Montreal has more cases, we do not know the percentage of people infected. “It may be that it is only a small percentage infected, according to Dr. De Serres. Therefore, there is little chance that the immunity that was played in Montréal in 2009 from happening this time. ”
Mutation of the virus
A second wave may occur when the virus mutates. “It is known that the Spanish flu was an H1N1 virus, but the virus had undergone in September a mutation important ? It remains a mystery “, said Mr. Gagnon.
“For the coronavirus, some say that the mutations are less common, but as no one has ever tested that one, so we still cautious,” says the demographer.
A second wave could also occur if the COVID-19 is seasonal, such as H1N1. “For the other coronaviruses, there is a seasonality. These are viruses that give the cold and transmit more in the winter as in the summer, but this is a new virus we don’t have the answer, ” said Nicholas Brousseau, medical officer at INSPQ and co-author of the balance sheet of 2009.
“It may be that the weather conditions during the summer period will be less favorable, but to think that this would be sufficient to reduce the epidemic, the hopes are very slim,” says Dr. Greenhouse.
Bet on the distancing
Thus, the public health does not focus on mother nature to stop the pandemic and prevent a second wave, but rather on the social distancing, insists Dr. Greenhouse.
Dr. Brousseau recalls that in 2009, there had not been a containment measure to prevent the spread of H1N1.
“This year, the measures of distance have an important impact to prevent more hospitalizations and deaths. The question is to find the balance to return the most possible to the normal life without recrudescence important of the infection. ”
Pandemic H1N1 in Quebec in 2009
- First wave : 2566 persons infected and 25 deaths
- Second wave : 10 809 infected persons and 81 deaths
- The median age of death was 60 years of age
- The virus entered the country by travellers in income in Mexico and has spread in two schools in Montreal and Quebec city
The Spanish flu in 1918-1919
- 55 000 deaths in Canada and 14,000 in Quebec and about half a million Quebecers infected
- 50 to 100 million deaths worldwide, 90 % in the second wave
- The victims are mostly adults between 20 and 40 years
- In Canada, the flu has arrived in the port cities of Quebec, Montreal and Halifax, before spreading across the country