Now that countries are advancing in their vaccination plan and putting all their hopes in the serum of recovering the normality snatched by the coronavirus pandemic , they are concerned about the new variants that have emerged and threaten the effectiveness of vaccines to deal with them.
The image shows a 3D print of a spike protein on the surface of SARS-CoV-2, the virus that causes COVID-19.
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British, South African, Brazilian … Little by little, new strains of SARS-CoV-2 have been appearing and have spread throughout the world. Experts recall that the mutation of viruses is very frequent, but they point out the need to pay special attention to those that affect the gene that encodes the famous protein S , the key to entry into the body and the target of the vaccines developed, since “they could condition changes in the infective capacity of the virus and in its sensitivity to the immune response induced by vaccines “, according to the Advisory Committee on Vaccines ( CAV ).
In fact, one of the debates that has been on the table in recent months is the possibility that vaccines that have been developed – or are in it – against the virus, should be updated frequently (as is the case, for example, with the flu) so as not to lose track of the coronavirus and its possible mutations. In addition, there are still no conclusive data on to what extent these new strains harm the ability of different vaccines to neutralize the virus, although some studies (so far done on a small scale) allow an idea of the effectiveness of each of them. versus the different variants.
Vaccine effectiveness against new coronavirus variants.Vaccine effectiveness against new coronavirus variants.Henar de Pedro
Colored electron image of an isolated coronavirus particle in the UK.
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The one known as the British variant ( B.1.1.7 ), which was the first to set off alarms last September, is the least worrisome, despite its greater transmissibility and its possible impact on the severity of the disease .
Already present in 94 countries, this variant does not appear to be strong enough to nullify the effectiveness of the Pfizer, Moderna, AstraZeneca and Novamax vaccines (still in clinical trials), whose laboratories have ensured that the protection capacity is maintained after injecting both doses. Of course, there is a mutation of this same variant ( E484K ), also present in the South African, which is of particular concern, as it could harm the effectiveness of the sera.
South African variant
Specialized personnel from Huoyan’s laboratory conduct a test for the new coronavirus (2019-nCoV) in Wuhan, China.
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Less encouraging are the data compared to the South African variant ( B.1.351 ), which has also presented greater transmissibility and is already present in 46 countries. The Pfizer and Moderna vaccines have found that their vaccines are six times less effective against this strain than against the original, with which the studies were carried out for which their marketing was authorized.
As both laboratories have announced, they are currently working on developing new prototypes that better neutralize the South African variant. The AstraZeneca scientists are also in it , since its efficacy against B.1.351 is practically non-existent ( 10% , when in the studies with the original sequence it proved to bebetween 62% and 90% ).
That of Johnson & Johnson , for its part, is the one that sees its ability to neutralize the virus the least reduced, although the percentage is still considerably low. According to the company, its vaccine -which, unlike the previous ones requires a single dose- acquires an efficacy against this variant of 57% (in the studies it was shown to have a 66% “general” effectiveness) in moderate disease- serious. Although they did announce that it prevents the most serious disease to 85% “in all the regions studied “.
A percentage similar to that of Novamax, whose vaccine experiences a 50% drop in efficacy against the South African variant.
This is perhaps the variant of the coronavirus for which there is less data to date, although it is estimated that it may have a greater transmission capacity. Present in 21 countries (the first case was reported in Spain on February 8), the Brazilian variant seems to have a similar impact to the South African on the effectiveness of vaccines , although the data available so far do not allow us to obtain any final conclusion.
The peculiarity of this new variant is that it has 12 mutations in protein S , including the N501Y mutation (as in the British and South African) and E484K, “which could be associated with an escape from neutralization by monoclonal antibodies”, according to the Ministry of Health warned .