Do we have to worry about the new variant?

Not much more than the existing variants. Changes in viruses are natural. They are therefore an expected phenomenon and should not worry us.

The different viral variants, which have been identified since the beginning of the pandemic, are mainly the result of the adaptation of the virus to its new host (the human species). However, these mutations could have an impact, quite difficult to predict, on the transmissibility and/or severity of the infection and on how they escape the immune responses (whether vaccine-induced or naturally occurring). In the first case, the implications would be short term with increased overload on the health system through increased cases and hospitalisations, while in the second case the impact would be long term with a lack of control of the pandemic.

For this reason, we must remain very vigilant in identifying relevant mutations. Mutations in SARS-CoV-2 need to be identified proactively (sequencing as many viruses as possible). This proactivity must also include epidemiological surveillance in order to associate these mutations with potential changes in transmission or mortality in the geographical areas where viral variants are identified.

What do we know?

The new variant contains 17 mutations, of which 9 are located in the S protein (69-70 deletion, 144 deletion, N501Y, A570D, D614G, P681H, T716I, S982A, D1118H). It is likely that this new variant has arisen from a situation of selective pressure on the virus, where it has been forced to generate and accumulate mutations (some possibilities are a jump between species or prolonged replication in the presence of antibodies). Its origin is not yet known, and whether it has occurred in the UK or not.

Prior to the identification of this variant, different parts of the virus containing some of these mutations have already been identified, including those affecting the region where the recipient is linked to the virus (such as the N501Y mutation in South Africa). However, they have been associated with a level of transmissibility such as that reported to the UK, and this variant is associated with an increase in cases in the south-east of England. Although this appears to be an increase in transmissibility, we must take into account that:

• Increased transmissibility does not mean increased pathogenicity/virulence/gravity.
• Increased transmissibility does not mean increased vaccine resistance.

For example, variant D614G, which is currently the most common and has a higher transmissibility compared to the original virus, does not affect the severity of the infection or the protection conferred by the vaccines.

No objective data are currently available that would suggest that the new variant could produce a more severe disease (epidemiological data are being collected to answer this question).

Nor are there any experimental data that would allow us to know whether the antibodies generated by the vaccines or by the natural infection neutralise this new variant. In any case, the immune response is polyclonal and directed against different regions of the S-protein, so a strong impact on vaccine efficacy is unlikely. Work is underway on virus isolation and virus neutralisation assays in the laboratory to provide a rapid answer to this question.

How can we act?

At the institutional level, molecular epidemiological surveillance must be prioritised. This requires constant monitoring of the variability of sequences and a capacity to analyse their implications, both:

• Epidemiological (monitoring of cases, severity, expansion of variants).
• Immunological, implications for protection by natural immunity or by vaccines.

It is important to note that the appearance of new mutations occurs during the replication of the virus. To limit this replication at the population level, vaccination campaigns are an essential tool. Accelerating these campaigns at the global level should be a priority.

Sequences similar to the new variant have been detected in other European countries and in Australia. It is therefore possible that it is circulating outside the UK. So, on a personal level, we need to continue to do this, taking extra steps to protect ourselves, to wear a mask, to maintain hand hygiene, ventilation and social distance.

This article has been written by Julià Blanco, Silvia de Sanjosé, Josep M Miró, Quique Bassat, Magda Campins, Robert Guerri, Carles Brotons, Juana Díez, Mireia Sans, Olga Rubio, Adelaida Sarukhan, from the Multidisciplinary Collaborative Group for the Scientific Monitoring of COVID-19.