A team of international researchers believes that once herd immunity is reached for COVID-19, in all likelihood through a combination of eventual vaccinations and natural infections/recoveries, the coronavirus will become a seasonal respiratory virus in countries and regions with a temperate climate (four distinct seasons, moderate weather patterns).
Back when the coronavirus pandemic started earlier this year, everyone was hoping it would disappear once the warm weather returned. We all know how that turned out. Summer 2020 will officially end next week, and COVID-19 has shown few signs of slowing down. Unfortunately, the study’s authors say COVID-19 will remain active across all four seasons worldwide until herd immunity is achieved somehow.
Even after that happens, COVID-19 won’t be completely gone. It will still emerge each winter as a seasonal virus in the same vein as influenza, according to the research team.
“COVID-19 is here to stay and it will continue to cause outbreaks year-round until herd immunity is achieved. Therefore, the public will need to learn to live with it and continue practicing the best prevention measures, including wearing of masks, physical distancing, hand hygiene and avoidance of gatherings,” comments senior study author Dr. Hassan Zaraket, of the American University of Beirut in Lebanon, in a release.
“This remains a novel virus and despite the fast-growing body of science about it there are still things that are unknown. Whether our predictions hold true or not remains to be seen in the future. But we think it’s highly likely, given what we know so far, COVID-19 will eventually become seasonal, like other coronaviruses,” Dr. Zaraket continues.
Most respiratory viruses typically follow seasonal patterns within temperate regions. It’s common knowledge that the flu re-emerges each year during the fall and winter months. Similarly, many other coronavirus varieties follow the same weather patterns.
Generally speaking, these older respiratory viruses fare much better in cold weather due to changes in humidity, fluctuations in human susceptibility to infections, and societal changes in behavior according to season. For example, the return to school each fall for millions of students creates the perfect environment for flu season annually.
That all makes sense, but why then, has COVID-19 failed to follow the same seasonal pattern thus far? It has a far higher rate of transmission (R0) than seasonal respiratory viruses like the flu. At least for now.
The reasons behind COVID-19’s super high R0 still aren’t fully understood, but researchers say it certainly hasn’t helped that all of our bodies had never really encountered a virus quite like SARS-CoV-2 before. In their words, the novel coronavirus has spent the past nine months circulating throughout “a largely immunologically naïve population.”
In short, once the majority of the global population attains that immunity, COVID-19’s R0 will drop considerably, and SARS-CoV-2 will become largely inactive each spring and summer just like any other respiratory virus.
When will herd immunity be reached? It’s anyone’s guess at this point. Hopes remain high that a viable vaccine isn’t all that far away, but until then the study’s authors are adamant that safety measures like social distancing and wearing masks are still very necessary.
“The highest global COVID-19 infection rate per capita was recorded in the Gulf states, regardless of the hot summer season. Although this is majorly attributed to the rapid virus spread in closed communities, it affirms the need for rigorous control measures to limit virus spread, until herd immunity is achieved,” concludes study co-author Dr. Hadi Yassine from Qatar University in Doha.
COVID-19 started as a faraway problem in China. Then, we all hoped it would be nothing more than a short inconvenience that only lasted a few weeks. Now, if these scientists’ predictions hold up, flu season each year may become coronavirus season.
The full study can be found here, published in Frontiers in Public Health.