Use of antibody in Covid-19 treatment: How effective is it neutralizing the virus

– By Dr KK Aggarwal

The use of Monoclonal Antibodies (mAbs) directed against infectious pathogens is an area of investigation. The mechanism is not completely defined. Potential uses include preventing or treating specific infections.

Most mAbs target proteins on the surface of a virus, thus neutralizing the virus from entering cells. Palivizumab is an antibody against the respiratory syncytial virus (RSV) fusion (F) glycoprotein; it inhibits viral entry into host cells. This therapy was approved by the US Food and Drug Administration (FDA) for the prevention of RSV infection. (‘Immunoprophylaxis’.)

Other investigational preventive antiviral mAbs include those targeting the conserved hemagglutinin A stem of Haemophilus influenzae. This therapy may be helpful in cases in which vaccination offers ineffective humoral immunity.

Investigational mAbs against HIV can improve immunity during active infection, with promising results in animal models using broadly neutralizing antibodies.

Some mAbs against bacteria can function both prophylactically and therapeutically (eg, by targeting the protective antigen domain of Bacillus anthracis or one of the Clostridioides [formerly Clostridium] difficile toxins).

As stated in a 2018 editorial, mAbs directed against pathogens are unlikely to be used routinely due to their high cost and requirement for parenteral administration; however, they may be especially useful for certain emerging infectious diseases.

Treatment of active disease and/or targeted prophylaxis might be especially important in individuals who have not been vaccinated against a pathogen but require immediate protection ( individuals infected with Ebola virus, pregnant women residing in Zika virus-endemic areas and COVID 19).

((The writer is President, CMAAO, HCFI and Past national President IMA))