Covid, Omicron BA5 bypasses immunity but symptoms are mild – Corriere.it

From Margherita de Pac

The cases would continue to grow and become a prevalent subtype throughout Europe. After taking BA1, the incidence of infection is 7%.

1 What is Omicron BA5?

Answers virologist Giorgio Ball, head of the Italian Medicines Agency “IFA”. BA5 is a subtype of Omicron virus, prevalent in most parts of the world. Like previous BA1-2-3-4 lineages, a type of concern (alternative to anxiety) by the European Agency for the Control of Communicable Diseases, ECDC, based on rapid spread and circumvention Defending against antibodies (immune evasion) and causing serious illness.

Omicron BA5 has an infectious index very close to that of measles and is the most transmissible virus: an infected individual can infect another 15-18, a characteristic primarily associated with the ability to evade the immune response. Data from the College of Health shows that 7% of Italians who were infected with the BA1 subvariable when it was prevalent can become infected a second time. There is no evidence of a greater risk of disease.

From South Africa, where it originated in February 2022, and not from Portugal, the European country where it initially spread, without affecting the rate of hospitalizations. Everything indicates that cases will increase in the rest of Europe and that Omicron BA5 will become dominant over other sub-variants without putting pressure on health systems. The incidence of infection is also increasing in Italy: we went from 207 cases per 100,000 inhabitants at the end of May to 222 cases between June 3-9. The intensive care and medical departments are not growing. (See also the five cases in Milan today.)

The South African population consists of many patients with weakened immune systems from other infections (tuberculosis, AIDS). Viruses such as SARS-CoV-2 have a greater chance of surviving in a chronic form in an organism that cannot reject it and thus be subject to mutations.

5 Why bypass immunity?

Thanks to two additional mutations compared to the delta variant, which is located on the S protein, which is responsible for binding the virus to the receptors of human cells. These changes partly give him the ability to evade the antibody response (allowing us to prevent infection) but not cellular immunity (which has the function of eliminating the virus from tissues and making us recover earlier).

6 Are Vaccines Effective?

Although all current vaccines are based on the original Wuhan strain that circulated two and a half years ago, they induce 90% protection against severe forms (if you have been vaccinated with a full course, two doses plus a booster dose). That is why it is important to do the third and fourth doses (for the frail, the elderly over 80, the immunocompromised, and nursing home guests). From September to October, we count on the availability of new vaccines based on the Omicron variant. Pharmaceutical companies Pfizer and Moderna have progressed well in the licensing process.

Mild forms of disease. Sore throat, runny nose, cough and fever. Like the other sub variants, Omicron BA5 primarily affects the upper respiratory tract and is characterized by three mutations that make it less contagious to the lungs.

A highly circulating, non-highly virulent virus capable of producing natural immunization for a large part of the population in addition to the synthetic virus produced by a full vaccination cycle (3rd and 4th booster dose). This hybrid immune system is highly protective against disease and is able to stop the spread of the epidemic. The virus will persist but will occur seasonally. We will find preparations with updated vaccines (eg flu shots) and new antivirals.

Jun 12, 2022 (change on Jun 12, 2022 | 19:39)

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