More transmissible, but overall capable of fewer serious consequences. It was the conclusions of a study on the Omicron variant released by the British Health Security Agency that made Israel desist (for the time being) from immediate use of the fourth dose. If on the one hand the aim is to reduce the circulation of coronavirus with restrictive measures of varying intensity, on the other hand the strategy of most countries focuses on the widest administration of boosters, of which comforting evidence comes.
WHO: it is in 110 countries, the rate is falling in South Africa
According to updated data from the World Health Organization, the new strain of SARS-CoV-2 now affects 110 countries and there is no longer any doubt about its substantial growth advantage over Delta, with a doubling time of two- three days. Estimates of progression in South Africa “are now falling”, but for the WHO “it is still uncertain to what extent the rapid rate of growth observed since last November can be attributed to immune evasion or increased transmissibility”, or “probably a combination of both”.
English report, lower chances of hospitalization
Up to 70 percent less risk of being hospitalized after being infected with Omicron than with previous variants. This makes the first results of the research carried out by the British health security agency considered “encouraging”, in which, however, it is highlighted that the protection from the Omicron variant begins to decline ten weeks after receiving the booster dose of the vaccine. This, however, continues to provide a considerable shield from major complications. The UK report shows that people infected with Omicron are 31% to 45% less likely to go to the emergency room than the Delta. And from 50% to 70% less than having to resort to hospital treatment in a real hospitalization regime. Even if a (potentially) larger audience of simultaneous cases could constitute a problem of saturation of the structures.
From laboratory tests less active vaccinated antibodies
Covid vaccines could lose some of their effectiveness in the face of the Omicron variant. Five works just published in Nature and conducted by David Ho of Columbia University in New York on all vaccines in use, as well as on monoclonal antibodies approved as anti-Covid therapy, go in this sense. A series of laboratory tests showed that the neutralizing effect of vaccine-induced antibodies (Pfizer-BioNTech, Moderna, Johnson & Johnson, AstraZeneca) in 54 subjects – including 15 undergoing the third booster dose – is low against Omicron . The efficacy of monoclonal antibodies developed against other virus variants is also low. The vaccines in use against the coronavirus all work by inducing the immune system of the vaccinated to recognize and attack the Spike protein, therefore, the researchers explain, a reduction in the effectiveness of the vaccines against Omicron which has a Spike protein rather different from that of the previous variants of SARS-CoV-2, with over 30 variations on its sequence. The experts also isolated four other new variations on Omicron’s Spike protein.
Effective third doses, company data agree
In Italy, from the provisional data of the Higher Institute of Health, Omicron is already responsible for 28% of infections with a doubling time of about two days, therefore in line with the WHO. As for the effectiveness of the third dose of vaccines to control the new variant, AstraZeneca also confirmed that the booster administration of its vaccine restores the neutralizing capacity that was conferred by two doses against Delta. Moderna and Pfizer-BioNTech previously also provided data on their products. The third administration of Moderna, halfway through the dosage, increases the protection against Omicron 37 times compared to that conferred by the two doses. With full dosage, the protection increase is 83 times. The Pfizer-BioNTech vaccine, on the other hand, with three doses is able to neutralize the variable with the same effectiveness with which two doses blocked the original version of the SARS-CoV-2 virus. Novavax, the manufacturer of the last of the vaccines approved in Europe, is also on the same line of good efficacy against Omicron. While in January it could start with human tests of a new ad hoc preparation for the variant.