Thanks to the colds that accompany the colder months of the year, we are very familiar with the seasonal patterns of some respiratory viruses.
A new review published in Frontiers in Public Health suggests that COVID-19, a disease caused by the SARS-CoV-2 virus, will likely follow the lead of other diseases caused by viruses, such as the common colds, and will become seasonal in countries with temperate climates. Of course, as specified, this will only happen when collective immunity is achieved through natural infections or vaccines. Until then, COVID-19 will continue to circulate throughout the year.
The study’s lead author, Dr. Hassan Zaraket of the American University of Beirut, warns: “COVID-19 is here to stay and will continue to cause outbreaks throughout the year until herd immunity is achieved. Therefore, the population must learn to live with it and continue to implement preventive measures, including the use of masks, physical distancing, hand hygiene and limiting meetings ”.
Another author, Dr. Hadi Yassine, from the University of Qatar in Doha, claims that there could be multiple waves of COVID-19 before herd immunity is achieved.
Several countries are battling the second wave of the virus after a devastating first wave of spread, while some are still in the middle of their first wave. In an attempt to find out if the SARS-CoV-2 coronavirus will become seasonal, the scientific team reviewed current knowledge about the seasonality of respiratory viruses, including coronaviruses and the viral and host factors that govern their seasonal pattern. In addition, the properties of SARS-CoV-2 and the potential impact of meteorological factors on its spread were discussed.
Many respiratory viruses follow seasonal patterns, especially in temperate regions. For example, influenza viruses and several types of coronaviruses that cause the common cold, such as the NL63 and HKU1 coronaviruses, are known to peak in winter in temperate regions, but circulate year-round in tropical regions. .
The authors reviewed these seasonal viruses, examining the viral and host factors that control their seasonality, as well as the latest insights into the stability and transmission of SARS-CoV-2.
The researchers explain that survival of the virus in air and on surfaces, people’s susceptibility to infection, and human behaviors, such as overcrowding indoors, differ from season to season due to changes in temperature and humidity. All these factors influence the transmission of respiratory viruses at different times of the year .
However, compared to other respiratory viruses like the flu, COVID-19 has a higher transmission rate (what we know as R0). This means that, unlike flu and other respiratory viruses, the factors that govern the seasonality of viruses cannot yet stop the spread of COVID-19 in the summer months. But once herd immunity is achieved through natural infections and vaccines, the R0 should decrease substantially, making the virus more susceptible to seasonal factors.
References:
Amani Audi, Malak AlIbrahim, Malak Kaddoura, Ghina Hijazi, Hadi M. Yassine and Hassan Zaraket. Seasonality of Respiratory Viral Infections: Will COVID-19 Follow Suit? Front. Public Health, (15 September 2020) https://doi.org/10.3389/fpubh.2020.567184
Fuente original: Frontiers Science News
