There are now a variety of articles and reports circulating that discuss whether or not viral activity of COVID-19 subsides when the weather warms up. While the research is inconclusive and we have not yet had warm weather experience with the virus in the Northern hemisphere, some of the reports suggest that, virus activity is inhibited when temperatures and humidity warm up beyond 22.22° Celsius (72° Fahrenheit) and 50% humidity, for example.
On the other hand, according to a Reuters report from Brussels, on March 25, the European Centre for Disease Prevention and Control announced a study predicting only a small likelihood that the spread of COVID-19 would end come summer. The ECDC study found that the virus did not become less dangerous in tropical zones with high temperatures and humidity, such as Singapore.
The results, according to the ECDC, emphasize “the importance of implementing intervention measures, such as isolation of infected individuals, workplace distancing, and school closures.”
So, what is going on here? Could the COVID-19 virus in Europe be more viable than the COVID-19 virus elsewhere?
This being unlikely, I would venture a guess that behind the disparity between the studies is the brevity of our experience and differing research methodologies.
From the start, there were those who said the virus would stop spreading once the heat and humidity of summer arrived. Meanwhile, others pointed out that the virus was spreading in tropical Singapore, making it pointless to hold out expectations for improvements due to temperature and humidity.
As the debate got stuck in this infinite loop, governments around the world decided against adopting policies based on weather conditions.
I found this strange, and wondered why they came to this conclusion.
There is research on the one hand that reportedly reveals that the virus is infectious, even in tropical areas. On the other hand, there is contemporaneous research which purports to show that viral activity subsides at 50% humidity with 22.22°C (72° F).
Yet, in my view they are not necessarily mutually exclusive.
First: Research the Enemy’s Weaknesses
Consider the theory that viral activity subsides when both humidity and temperature conditions are met. Under this analysis, the virus could be fully active when temperatures exceed 22.22°C (72° F) but there is low humidity, or when buildings are air-conditioned.
It is quite a simple matter to raise indoor temperature by adjusting temperature settings on heating equipment. At the same time, increasing humidity as much as possible may not stop viral activity completely, but could be effective in hampering it.
It is worth noting that, although infections have occurred in tropical areas of high heat and humidity like Singapore, they have not become as explosively rampant as they have in Europe and New York.
In Japan, the virus spread quickly in Hokkaido, but not in Okinawa. In the United States, the virus spread like wildfire in colder states, such as Washington and New York.
I infer that this phenomenon is due to two factors. First, the virus is well-suited to low temperatures and dry conditions, in which case the number of infected persons is higher. Second, the virus is less suited to and slows down in hot and humid conditions, in which the number of infected persons is lower.
Thus, I cannot comprehend why the WHO and world leaders have not put more effort into understanding the effect of high temperature and humidity on the virus.
Factoring In Heat and Humidity
People have been told that good ventilation helps, or that they should talk with others at a distance so droplets carrying the virus cannot reach them. Moreover, avoid crowds. All of these measures imply that it is okay to be outside. So people had barbecues and cherry-blossom viewing parties.
I think if we factored in “heat and humidity” to the equation, the rate of infection could be lowered even further.
In short, I would like the ECDC, as well as their respective American and Chinese national research institution counterparts, to separate their inferences from the facts. They should release accurate information that will not be misunderstood by the public.
These are highly regarded public institutions that are trusted by the public, who believe what they say. Thus, they should take great care before releasing comments about incomplete research.
The development of medications to treat the virus and vaccines to prevent it is crucial. However, I believe that we should gather information from around the globe that will help us to understand the weaknesses of this virus, the enemy of mankind. From this research, unbiased, accurate information should be conveyed to people around the world.
Author: Nanae Hasegawa
Nanae Hasegawa is a blogger who lives in Chiba Prefecture and publishes the online comic strip entitled, “Alien Sakurada, Laughing at the World”. https://note.com/nanaehasegawa/n/nb10d16fcd281 and Twitter: @hasegawananae17