PARIS —The rate of transmission and death toll of the coronavirus finally seem to be slowing, and various national and local lockdown measures are beginning to loosen. In a best-case scenario, both commerce and public confidence pick back up and social distancing measures help the virus to fade away by the summer. But even if that's the case, health officials are warning that a second wave of infection later in the year, as winter approaches in the Northern Hemisphere, is not only possible but probable.

A seasonal link: Though the behavior of the current coronavirus is still fairly unknown, researchers have reasons to believe that this virus shares many characteristics of other (less-deadly) coronaviruses we have faced before, including the one which causes the common cold, where transmission is much higher in the fall and winter than in the summertime, which may also be linked to the strength of the body's immune system. Most disease specialists have come to believe that the coronavirus will also follow a similar seasonal pattern. Dr. Amesh Adalja, an infectious disease specialist at Johns Hopkins University, told The Los Angeles Times: "I suspect this will come back and if we do get any kind of lull in the summer that this will likely pick up in the fall, just like other coronaviruses do."

Reaction time: Director of the National Institute of Allergy and Infectious Diseases, Dr. Anthony Fauci says that a second wave of the coronavirus is "inevitable" in the fall or winter, the only difference is that there is still time for the government to put countermeasures in place that would curb the spread. Last week, researchers at the Center for Infectious Disease Research and Policy (CIDRAP) released a report with at least three possible outcomes for COVID-19's future spread across the country.

Worst case: CIDRAP's worst-case scenario prediction, and also the most likely according to them, is not only that there will be a second wave of the pandemic in the fall and wintertime, this second wave is also estimated to be even larger than what we have been witnessing. According to the author of the report and director of the CIDRAP, Michael Osterholm, the disease will not stop spreading until it has infected at least 60-70% of people (which has been estimated to take anywhere from 18 to 24 months and assumes that these people survive the disease). He says, "The idea that this is going to be done soon defies microbiology."

Control & prevention staff working in the snow in Suifenhe, China, on April 22 — Photo: Zhang Tao/Xinhua/ZUMA​

View from Iran: In Iran, one of the countries initially hardest hit by the coronavirus, doctors are warning authorities that they may be in for another viral winter. Though Iranian officials have been suggesting that the pandemic is currently peaking nationwide, like the Health Ministry's calculations from May 4, which show a decline in infection rates in some provinces and the possible approach of a peak in others, physicians in Tehran predict that next winter will not be anything like a routine flu season. Mas'ud Mardani, an infectious disease doctor and member of the capital's coronavirus headquarters, told the daily Aftab-e Yazd that if the country imported "two million flu vaccines last year, this year it must import between 10 and 20 million vaccines at least," to cover all "vulnerable" people.

French low immunity: As reported by Le Figaro, with France beginning to lift the strict confinement measures that have been in place since mid-March, Prime Minister Edouard Philippe reminded citizens of the difference between loosening restrictions and being in the clear when it comes to the spread of the virus. "The risk of a second wave, which would hit a weakened hospital system, would impose a return to quarantine," he said. "That would ruin the efforts and the sacrifices made." And this risk is very real, according to research published by France's Institut Pasteur, the confinement measures put in place successfully reduced the transmission of the coronavirus by 84%. However, they predict that by the time measures begin to loosen on May 11, only 5.7% of the population will have been infected, meaning that when control measures are loosened, population immunity will be insufficient to prevent a second wave.