Getting a COVID19 protective response


You may have heard of REGEN-COV. This is an antibody cocktail that pre-prevents the SARS-CoV2 virus from binding to human cells to prevent infection of humans and was given to ex-president Trump. They are made and used as a pair to stop the virus escaping destruction.

This has been given a name of Ronapreve that can be used to prevent infection, promote resolution of symptoms of acute COVID-19 infection and can reduce the likelihood of being admitted to hospital due to COVID-19.

The active substances are casirivimab or imdevimab. Each single-use 6 mL vial contains 300 mg of casirivimab or imdevimab. Other combinations are bamlanivimab and eteseevimab another is AZD7422 consists of two long-acting antibodies (LAABs), tixagevimab (AZD8895) and cilgavimab (AZD1061)

Neutralizing monoclonal antibodies for treatment of COVID-19 | Nature  Reviews Immunology

This has been approved, but it is not clear on the precise indication in the UK. This cocktail is made by the manufacturer of anti-CD20 (ocrelizumab and rituximab). This may have the potential to give you an antibody response if you do not make one after anti-CD20 depletion

Luitel P, Vais D, Gidron A. Successful Treatment of Persistent Coronavirus Disease 2019 Infection in a Patient With Hypogammaglobulinemia With REGN-COV2: A Case Report. Open Forum Infect Dis. 2021;8(8):ofab335. 

A 55-year-old man with hypogammaglobulinemia due to previous rituximab treatment developed persistent coronavirus disease 2019 pneumonia. Treatment with REGN-COV2 (casirivimab and imdevimab) resulted in the clearance of the infection. Targeted antiviral antibodies may be an important weapon in the management of immunocompromised patients infected with severe acute respiratory syndrome coronavirus 2 who fail to mount an immune response.

Drouin AC, Theberge MW, Liu SY, Smither AR, Flaherty SM, Zeller M, Geba GP, Reynaud P, Rothwell WB, Luk AP, Tian D, Boisen ML, Branco LM, Andersen KG, Robinson JE, Garry RF, Fusco DN. Successful Clearance of 300 Day SARS-CoV-2 Infection in a Subject with B-Cell Depletion Associated Prolonged (B-DEAP) COVID by REGEN-COV Anti-Spike Monoclonal Antibody Cocktail. Viruses. 2021 Jun 23;13(7):1202.

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  • Can you comment on the AZ LAAB approach, would that make for longer lasting prevention vs the Regeneron mix?

    Sadly, neither is currently on the market for prevention where I live.. Guess I’ll try my luck with a third mRNA shot in the meantime…

    • Yes the LAAB approach increases the time the antibody can stay in the body. In the regeneron antibodies the half life is about 26-28 days, i the LAAB the eantibody is engineered to not act via the Fc receptors so it doesnt get sucked up by macrophages and can last for months

  • Will it be of use to solid transplant patients? A friend’s daughter who is one such cannot see how she can ever return to normality.

  • Grateful for availability of cocktail is my community, especially being on anticd20 DMD. but really concerned about PR that it’s touted as the panacea to prevent severe illness and reduce burden on hospitals. Here in TX, Huge spike, no room in hospitals, outlawed mask mandate, unvaccinated at large, but sudden accessibility to cocktail: the age requirement for infusion was reduced from 55 to 12. Years of age. Common refrain seen on social media here is how great someone feels after getting cocktail. After 3 months and the monoclonal antibodies wane in body, what happens? How many times can someone use it safely, and will it create a tolerance?

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