United Kingdom: detection of worrying South African variants

The UK government has announced a massive testing campaign in south London, urging all residents of Lambeth and Wandsworth, or 650,000 people, to take a coronavirus test after finding cases of the E484K variant.

The discovery, which worries health authorities, comes after a de-escalation that will begin on Monday with the opening of pubs, shops and sports halls in the country. At the same time, Israel and the UK are being watched by the rest of the world to measure the effectiveness of the vaccination processes they conduct.

From Thursday they will start testing people for the variant in and around Finchley in the Barnet district. This “gigantic” tracking operation, as described by those in charge, it affects all adults, even if they do not have obvious symptoms of COVID-19 infection.

The variant is of concern because contains the “E484K” mutation, which is believed to significantly reduce the effectiveness of the AstraZeneca vaccine. Official projections indicate that this development, developed in collaboration with the University of Oxford, accounts for between 70 and 80 percent of all injections that have been administered in the UK.

At the start of screening, traceability analyzes for this mutation indicate that the virus was transmitted by a person who arrived from Africa and spread to members of their household. Then these people infected her by a nursing home in Lambeth, where 13 staff and 10 residents were infected.

The data also indicates that 6 of 10 residents had received a dose of AstraZeneca vaccine two weeks or more before the date of a positive sample. Among them, one of 13 infected employees received a single dose of Pfizer vaccine two weeks or more before testing positive.

Efficacy of the AstraZeneca vaccine against the South African variant

SARS-CoV-2 has accumulated several mutations of interest. In particular the British mutation which has reached a greater affinity of the virus with the receptor, which increases its transmissibility.

The South African variant comprises a total of three mutations, including mutations N501Y, K417N and E484K, the latter detected in London.

According to a study carried out in South Africa, but which must be compared with other studies, between June 24 and November 9, 2020, the vaccine was analyzed in 2,026 adults (average age 30 years). The tests showed greater resistance of the South African variant in the serum samples of the vaccinated people than in those of the placebo.

It is this finding, more than any other, that explains why ministers in Boris Johnson’s government are already planning. a “booster” campaign with a new formulation of the AstraZeneca vaccine in the fall. The researchers do not even rule out that a third dose may be offered after the European summer.

Seek herd immunity

As the latest figures from the Office for National Statistics show, about 54.9% of people in England had antibodies in the week ending March 28, no change from two weeks earlier.

During, antibody levels seem to have gone down in older people while waiting for a second dose of vaccine, says a book that appears in the British newspaper The telegraph. At the same time there is Some suspect that the immune response wanes as vaccination rates begin to exceed the proportion of people reporting antibodies.

However, This does not mean that people without detectable antibodies are not protected by other elements of the immune system, experts asserted.

People aged 65 to 69 had the highest level of detectable antibodies at 84.5%, suggesting that the effect is most noticeable in people a few weeks after vaccination.

The lowest antibody levels are found in people aged 16 to 24, 38.7 percent, where a previous infection with COVID is likely to play a significant role.

Finally, the vaccination campaign continues, even despite the controversies over rare cases of coagulation and thrombosis allegedly linked to the developments of AstraZeneca and Johnson & Johnson. Data shows that 76,123 people received their first dose of a covid vaccine on Tuesday, bringing the total to 32,326,604.

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