Many experts are predicting that the number of infections by SARS-CoV-2 or the new coronavirus (which causes the respiratory disease COVID-19) would decrease with the arrival of heat in the northern hemisphere. At the moment, there are 114,567 confirmed cases worldwide, 4,000 deaths and more than 64,000 recovered. Governments’ effort to contain this epidemic is aimed at not having to fight a new type of life-threatening respiratory disease every winter, especially while vaccines and viral treatments are developed.
This data is related to the belief (misunderstood) that the cold is the cause that we get sick, and that colds and cases of seasonal flu occur. But this statement is not exactly true: the cold does not directly cause colds or the flu, but creates an environment more conducive to sickness. We explain it.
Cold makes viruses thrive
Viruses that cause common colds or flu (rhinovirus and influenzavirus respectively) thrive best in cold temperatures; the preventive doctor Daniel Orts explains: “Normally all these respiratory viruses, if they increase in winter, it is due to ambient temperatures and because they work better and reproduce their life cycle better in cold temperatures”.
The cold makes us more vulnerable
On the other hand, low temperatures would dispose our body to present more vulnerabilities and less defensive effectiveness when it comes to defending against some infections. There is some clinical research studying the effect of exposure to cold on susceptibility to infection with the common cold virus.
For example, a study published by the journal PNAS , using an animal model, showed that in cells of the airways of mice, rhinovirus preferentially replicated at the temperature of the nasal cavity due, in part, to a defense response. less efficient antiviral of infected cells in cool temperatures.
Rhinovirus is the most common cause of the common cold, as well as one of the most important causes of asthma exacerbations. Most rhinovirus strains replicate better at low temperatures found in the nasal cavity than at lung temperatures, but the underlying mechanisms are not known.
In addition, other dynamics converge that could encourage viruses to spread more easily, such as confinement in closed places or exposure to heating, which dries out our mucous membranes. But what causes these conditions is not the cold itself, but that you have to be exposed to the virus yes or yes.
The nature of this new coronavirus is increasingly known in more detail: we already know that it comes from group 2B, from the same family as SARS. Therefore, the prior knowledge we have about rhinoviruses, influenza viruses and other coronaviruses makes experts think that, with the arrival of heat, infections will decrease (at least in the northern hemisphere, which is where the vast majority of the patients).
For now, it only remains to wait and for each country to apply, in the best possible way, the measures to contain the spread. At this time, clinical trials for the development of a vaccine and two promising active ingredients to serve as antivirals are already underway.
