Hunting for a weapon against Covid-19, Indian Council of Medical Research (ICMR) have now taken recourse to a decade-old strategy to extract antibodies from horse blood for the treatment of novel coronavirus patients.
“ICMR and Biological Evans, Hyderabad, have developed highly purified anti-sera (raised in animals) for prophylaxis and treatment of Covid-19. Such measures have previously been used in medical science to control many viral and bacterial infections such as rabies, hepatitis-B, vaccinia virus, tetanus, botulism and diphtheria,” the health research agency said in a tweet.
Although the plasma recovered from patients experiencing Covid-19 could serve a similar purpose, ICMR claimed that the anti-sera from the animal blood is a better option since the profile of (human) antibodies, their efficacy and concentration keep varying from one patient to another because of which human plasma was an unreliable clinical tool for patient management.
“On the other hand, standardisation of the antibodies are achievable through equine sera based treatment modality,” tweeted the agency.
While countries like Brazil and Argentina are trying to develop a therapy with antibodies produced in horse blood, researchers at the University of Texas, Austin, used a llama to generate antibodies against Covid-19. All such therapies are still in the research stage.
In the Indian project, the antibodies were generated by scientists at the National Institute of Virology, Pune and the drug firm.
“The study provides evidence of the potential of generating highly purified antibodies from equines against SARS-CoV-2 that can demonstrate consistent and high neutralization activity. Further, in-vivo testing for the efficacy of this indigenous cost-effective product will pave the way to clinical evaluation,” the scientists reported in the journal Virology.
“Additionally, being a donor independent method, this may prove as an efficient alternative to convalescent plasma for treatment of Covid-19 patients.”
Independent scientists, however, raised questions that need to be settled before the use of such anti-sera can be an effective therapy against Covid-19 after going through the clinical evaluation process.
“It’s an approach that is used and most effective mainly early in infection. The problem with Covid-19 is that one could be infected but asymptomatic for a few days. By the time symptoms appear the virus has multiplied sufficiently. since multiplication happens inside cells and antibodies cannot get into cells, such passive immunisation is not going to be very effective,” eminent virologist Shahid Jameel from the Ashoka University told DH.
“The infections where this technique is used are those in which the infection time is known. For example, you know when a dog bit and therefore take the anti-rabies serum. Same goes for Hepatitis-B, vaccinia, tetanus based on needle prick or cuts. Another area where it’s commonly used is against snakebite,” he added.