One year since Coronavirus pandemic, impact of weather still remains unknown- explained

It has been one year since the Coronavirus was officially discovered as a pandemic and given that the virus has gone through all seasons in a year, the impact of temperature/ weather remains an area that is yet to be fully understood. A report by The IE noted that the COVID-19 task team was formed by the World Meteorological Organization (WMO) and their research has not resulted in any concrete answers indicating the influence of several meteorological parameters on coronavirus cases. When the pandemic broke out, there were some speculations that this viral infection mainly impacting the respiratory function will show some seasonality. Considering how influenza spreads, many experts pegged that the viral load would spike in autumn and winter months whereas the infection rate was expected to be less in temperate climate regions and during summer months.

Many variations were also predicted depending on the altitude, geographical location as well as the inter-annual variabilities. However, one year down the line, the results are not how they were predicted and some even showed contradictory and uncertain results. The report noted that the immunology of various populations played more role than the environmental factors. The seasonality, opposite to what was expected, played rather a small role. The first report by the WMO pointed out that it is yet to know till what extent, seasonality impacted the COVID-19 caseload or led to mortality across countries.

The report was prepared based on three meteorological parameters- air temperature, humidity and ultraviolet radiation. The impact of UV radiations under controlled laboratory settings is something that has shown results when it comes to virus survival however, the study said that its importance when it comes to the transmission of virus has not been proved yet. Similarly, environments having cool temperatures (5°C) with relatively low humidity (20-35%) can give an impetus to virus transmission via aerosols. The report also said that large temperature variations can also lead to respiratory mortality increase.

Similarly, the impact of air pollution on Covid-19 infection is limited. But the pollution is capable of triggering immune system dysregulation that can lead to increased chances of developing comorbid conditions along with hospitalisation.

It is to note that while these factors may not have a huge impact on the Coronavirus transmission, people being together in a closed space having poor ventilation can lead to an increase in the viral load. It is said that extreme heat may force people to take their masks off further aiding transmission.

The study noted that the transmission was mainly curbed and impacted by the government interventions including lockdowns, mandatory usage of masks and travel restrictions. Apart from this, human behaviour, immunity of people, virus mutations and demographics contributed to transmission. Therefore, the task team has recommended that a government should not relax measures based on the meteorological factors and air quality.