The FDA gives green light to immunization with antibodies prior to exposure to Covid-19

The US Regulatory Agency FDA has issued an emergency use authorization on Wednesday (US) for the combination of monoclonal antibodies of AstraZenecaevusheld (TIXAGEVIMAB and CILGAVIMAB) for prophylaxis prior to exposure to Covid-19. Its use is authorized in people for which vaccination against coronavirus is not indicated or vaccines are not expected to provide adequate protection.

Unlike the rest of monoclonal antibodies authorized in COVID-19, Evusheld is not indicated as treatment for infection or to prevent the disease in people who have come into contact with the virus. This new combination is only authorized in people who at the time of administration are not infected by SARS-COV-2 and that have not been a person's recent contact with Coronavirus.

The drug can be applied in children and adults from 12 years and that weigh at least 40 kg. It is aimed at people for vaccines would not offer an adequate immune response from their state of immunosuppression due to an underlying medical condition or treatment with immunosuppressants. Also for those in which vaccination is not indicated by presenting antecedents of adverse reactions to these vaccines or to one of its components.

For its administration it is necessary to apply two consecutive injections, one for each monoclonal antibody. This form of passive immunization would offer protection for six months. The FDA recalls that Evusheld does not replace the Vaccines of the COVID-19 for the people in which vaccination is indicated.

Monoclonal antibodies are proteins elaborated in the laboratory that mimic the capacity of the immune system to combat pathogens such as viruses. TIXAGEVIMAB and CILGAVIMAB are long-acting monoclonal antibodies that are specifically directed against the peak protein of SARS-COV-2, which have been designed to block virus bonding and its entry into human cells. These antibodies are joined to different sites that do not overlap in the peak protein of the virus.

The FDA indicates that there are no adequate alternatives, approved and available to Evusheld, for pre-exposure prophylaxis in these people. The other monoclonal antibodies with authorization of emergency use by the FDA have been authorized to prevent the development of COVID-19 and its complications in people infected by SARS-COV-2. They are Sotrovimab (from GSK) and the combinations of Bamblanivimab and Etesevimab (Lilly) and Regen-VOC (Casirivimab and Imdevimab, Regeneron and Roche).

EVUSHELD's emergency use authorization is based on the Provive, Randomized, Double Blind and Placebo Clinical Test, in adults over 59, or with a pre-Specified Chronic Medical Condition, or with greater risk of SARS-VOC infection -2 For other causes, they had not been vaccinated and did not have a history of infection by Coronavirus and had not been positive in a diagnostic test at the beginning of the trial.

The trial evaluated the cases of COVID-19 before day 183 after receiving the medication. In this study, 3,441 people received Evusheld and 1.731 received a placebo. The application of monoclonal antibodies was associated with a reduction of 77% of the risk of developing COVID-19 against placebo. Additional analyzes showed that this risk decrease was maintained for six months.