Seasonality of Coronavirus & Other Respiratory Viruses

As the world continues to battle the pandemic, the USA has surpassed 8 million coronavirus cases in the last few days. The virus keeps changing its form and it’s becoming harder than ever to contain the spread. Meanwhile, a paper published in the Frontiers in Public Health reveals respiratory viruses are seasonal, but Coronavirus is not. 

Seasonality of Respiratory Viruses

Respiratory viruses such as the Influenza virus and SARS are found to be seasonal; this means the spread of these viruses increases in winter in temperate regions and during the rainy season in tropical countries. On the other hand, the communicability of these infections decreases during the summer. This is what we mean when we say respiratory viruses are seasonal. But, the question here is, is Coronavirus a seasonal virus? Will its impact and spread reduce during the summer?

The answer is a disappointing NO. With millions of deaths around the world due to the Corona crisis, there was some hope that the impact of the virus might reduce with a change in the climate. But, the recent study concludes that Coronavirus will exist year-round and unlike other respiratory viruses, it is a non-seasonal virus. Here are the factors that were taken into consideration.

Reproduction Number

For a virus to be seasonal, its Reproduction Number-R0 (A mathematical term used to gauge how contagious an infection is) should be less than 1. But, in the case of Coronavirus, the R0 lies between 2-3. And, in some cases, it is as high as 5.7. This is one of the pieces of evidence that reveals COVID-19 is not seasonal and can exist throughout the year. 

Warm Temperature

It was also found that the novel Coronavirus can survive up to 72 hours on a hard surface and there is no drop in the R0 during the summer. The spread keeps increasing when a person with less immunity comes in close proximity with an infected person, no matter what the season is.

In addition to this, the study concludes that Coronavirus can become seasonal like other respiratory diseases only when herd immunity is achieved and until then, it is essential for the public to take all the necessary precautions like wearing a mask and maintaining social distancing to protect themselves from the virus.