According to a new review, published on September 15, 2020, in the journal Frontiers in Public Health, the illness caused by the SARS-CoV-2 virus will likely become seasonal in countries with temperate climates, once the herd immunity is achieved. The transmission of the virus may plummet considerably, making it more prone to seasonal fluctuations. By that time coronavirus will continue to cause outbreaks year-round. Therefore, the public will, need to learn to live with Covid-19 and continue practising the best prevention measures, such as wearing of masks, maintaining physical distancing, practising hand hygiene, and staying away from social gatherings.
Besides, there could be multiple waves of Covid-19 before herd immunity is achieved.
As a matter of fact, many respiratory viruses follow seasonal patterns, especially in temperate regions. For instance, influenza and several types of common cold-causing coronaviruses peak in winter but circulate round the year in tropical regions.
On examining the viral and host factors that control the seasonality of viruses and on the basis of the latest knowledge on the stability and transmission of SARS-CoV-2, the researchers found out that virus survival in the air and on surfaces, people’s susceptibility to infections, and human behaviours, such as indoor crowding, differ across the seasons due to changes in temperature and humidity. Thus, varying transmission of respiratory viruses at different times of the year.
However, respiratory viruses such as the flu, Covid-19 has a higher rate of transmission (R0) compared to other, at least partly due to circulation in a largely immunologically naive population. This means that the factors governing seasonality of flue and other respiratory viruses cannot yet halt the spread of Covid-19 in the summer months. Once herd immunity is attained through natural infections and vaccinations, the R0 should drop substantially, making the virus more seasonal.
Courtesy: India Today, Sept 15, 2020