New COVID-19 variants threaten vaccination efficacy

Epsilon variant shown to be resistant to messenger RNA vaccines
vacunas-eficacia-variante-covid

REUTERS/WILLY KURNIAWAN  -   A health worker holds a dose of Sinovac vaccine

While developed countries are moving forward relentlessly with vaccination to tackle the COVID-19 pandemic, new variants of the virus are appearing, often calling into question the efficacy of vaccines. Currently, the Delta variant originating in India is causing what has already been dubbed a fifth wave in Europe.

The UK has been one of the European countries most affected by the spread of the Delta variant of the coronavirus, and the island also reported another COVID-19 variant on 20 December in the British county of Kent. The Alpha variant, with a greater power of propagation, caused havoc in the United Kingdom, which was forced to impose a new hard confinement on its population in order to curb the spread of the virus.

india-covid-vacunación-variante-delta
AP/ALTAF QADRI - A health worker takes a nasal swab sample from a passenger to test for COVID-19 at a bus terminal in New Delhi, India

In Spain, as in the rest of Europe, the predominant variant is Alpha. In seven of Spain's 17 autonomous communities the presence of the British variant is over 70%, but the Delta variant is also becoming a concern and its presence has already reached 11% in the last week. The appearance of new variants has been a constant since the SARS-CoV-2 virus appeared in Wuhan in 2019.

The main concern regarding the new variants is the effectiveness of the vaccines. For now, there is no evidence that vaccines are reduced in their effectiveness against the Delta or Alpha variants, but a new variant has called into question the effectiveness of certain vaccines, especially those created from messenger RNA such as Pfizer or Moderna. According to a study published in the journal Science, a new variant called Epsilon, originally from California, may have some resistance to the antibodies created by EU-approved vaccines.

vacuna-pfizer-variante-covid
AFP/ JOEL SAGET - Vaccine from Pfizer and German biotech company BioNTech

The study, conducted by researchers from the US and Switzerland, explains that this new variant detected in the US "carries S13I peak glycoprotein mutations in the signal peptide, W152C in the N-terminal domain (NTD) and L452R in the receptor binding domain (RBD)".

"These findings show that the three mutations present in the B1.427 / B.1.429 S glycoprotein decrease the neutralising activity of vaccine- and infection-elicited antibodies, suggesting that these lineage-defining residue substitutions are associated with immune evasion," the scientists explain.

proceso-vacunacio-covid19
REUTERS/LIM HUEY TENG - People wait in line to receive AstraZeneca's COVID-19 vaccine at a vaccination centre in Kuala Lumpur, Malaysia, May 5, 2021

The Epsilon variant was first detected last March and is already present in 44 countries, including the United States, South Korea, India and Japan. In Spain, for the moment, only one case has been detected in the Basque Country. The Basque Health Service itself confirmed this on 18 June, but assured that "it is totally localised".

Virologists agree that it is vitally important to continue with the vaccination campaign and to ensure that as many people as possible are immunised globally as soon as possible, otherwise more variants of the virus will continue to appear