Omicron, a more contagious, yet milder variant?

On 29 November, the Gregorio Marañón Hospital in Madrid confirmed the first Spanish case of infection with the omicron coronavirus variant. In recent weeks, coronavirus infections have increased exponentially in Spain, as well as in other countries around the world. However, in South Africa, where the omicron variant was first identified, cases are beginning to fall as quickly as they rose. This new variant, which is already predominant in the Netherlands and Switzerland, among other countries, has raised some important questions that the scientific community is trying to answer. Although, according to various experts, the omicron variant is more contagious than the delta variant, it seems that the symptoms are milder, thanks in part to the vaccination effort; therefore, fewer hospitalisations and deaths are being recorded than in other waves.

Asked by Mètode, both Salvador Macip, doctor and researcher at the University of Leicester (UK) and the Open University of Catalonia (Spain), and FISABIO researcher Alma Bracho agree that, «although the percentage of hospitalisations is lower than in previous waves, we cannot relax, because omicron’s high transmission generates a large number of cases, which translates into more people being hospitalised, albeit at a lower rate. The same is true for mortality».

The reasons why this new variant is more contagious than previous ones are still not entirely clear, but experts share the idea that it related to the parts of the respiratory system affected by this mutation of the virus. Alma Bracho explains that the omicron variant preferably infects the upper respiratory tract (from nose to throat) so, «when in contact with or talking to other people, the infected person expels more virus». For this reason, the most common symptoms of this variant are pharyngitis (nasal discharge) and nasal discharge. Furthermore, Salvador Macip adds, «it seems that this variant has less capacity to remain in the lungs, which contributes to making it is a less serious disease».

Another reason why this variant may be developing so quickly is how similar its symptoms are to those of other common respiratory illnesses that have been less common over the last two years, such as the usual colds typical of this time of year. «This can lead to confusing one illness with another, because the symptoms are similar. That is why tests and quarantines are important until you are sure of which infection you have», Macip assures. In Spain, the quarantine period for infected people has just been reduced, and there are even plans to eliminate the obligation to do so when the person who has had contact with a positive person has been vaccinated. Are these proposals coherent? Alma Bracho explains that it depends on various factors and, above all, on the particular situation in each country: «The decision to reduce the quarantine period, from a healthcare point of view, could be justified by the milder nature of the symptoms and the shorter recovery time that patients are currently experiencing». However, he points out that the adoption of these measures is motivated not so much by health reasons as by economic ones: «There is a problem: many essential services could be left without staff».

To understand why COVID-19 continues to change and can also affect vaccinated people, it is essential to understand the nature of these coronavirus variants. Viruses undergo mutations, i.e., small changes, all the time. In most cases, mutations do not affect their functioning, but from time to time, one of these variants helps the virus to adapt better to its environment (for example, by becoming more contagious). These mutations are the ones that end up dominating. Salvador Macip briefly explains what makes the omicron variant different from previous ones: «There are three main parameters that concern us about the variants: that they are more contagious, that they escape defences, and that they cause a more serious illness. The omicron, compared to the delta, is much more contagious, the antibodies do not fight it as well, but it seems that it causes milder cases». On the other hand, Alma Bracho acknowledges that, although the latest variants of the virus are showing greater transmissibility, they are not currently more virulent, «which may lead us to be optimistic and to think that the evolution of the virus will continue this trend».

However, this does not mean that we can expect the virus to disappear. «This virus is here to stay», says Bracho. However, the most likely evolution, she explains, is that COVID-19 will end up being similar to other coronaviruses that have existed for years and which we do not pay attention to because they do not pose much of a threat to the population. Between the immunity obtained through contagion and vaccination, Bracho continues, the virus «will gradually lose importance, it will become part of our lives and we will get used to it». But for this to happen, the vaccination process is essential. The researcher reminds us that in Germany, where the percentage of vaccinated people is lower than in Spain, there are currently three times more deaths from coronavirus. Salvador Macip also stresses the importance of immunisation: «the situation today is undoubtedly better than it was last year, and this is thanks to mass vaccination».

© Mètode 2021
Journalism graduate from the University of Valencia.