Monday, Jun 5, 2023

Horses hold key to Covid care?

Researchers explore possibility of utilising antiserum derived from the animals as a therapeutic in Covid treatment

By M. Sai Gopal

Published Date - 12:07 AM, Wed - 4 November 20

Horses hold key to Covid care? — In the current state of the pandemic, due to unavailability of approved specific vaccine and drugs for treating Covid, experts say there is an urgent need for therapeutic strategies.

Hyderabad: The ineffectiveness of human Convalescent Plasma (CP) technique in treatment of Covid positive patients has now made researchers and drug developers explore possibility of utilising antiserum derived from animals as a therapeutic in the treatment of Covid-19.

As part of these efforts, researchers from Indian Council of Medical Research (ICMR) and Hyderabad-based Biological E limited have reported the development of immunoglobulins, which are proteins in the plasma, from horses that can neutralise SARS-CoV-2.

In the trials that were conducted at Biological E Ltd, the researchers from ICMR-National Institute of Virology (NIV) chose 10 horses between the ages of four years and 10 years. The horses were inoculated with inactivated SARS-CoV-2 along with an immunity booster.

In the study, the ICMR-NIV researchers reported the preparation of equine hyper-immune sera to demonstrate their protective efficacy against SARS-CoV-2 virus. The antiserum was prepared by injecting inactivated whole virus antigen in horses subcutaneously for a period of 21 days. The plasma collected from the 10 horses were pooled to produce a plasma pool and was used to produce multiple batches of immunoglobulins at Biological E Ltd on a pilot scale. All the plasma produced was tested, which indicated good specificity or presence of antibodies raised in the horses against SARS-CoV-2.

The overall purity of the immunoglobulins produced from plasma processing was evaluated and all the batches of plasma that were pooled showed consistent purity of 99 per cent and minimal content of impurities, the ICMR and Bio E Ltd, in the preprint journal Resource Square, said.

The antibodies derived from horses had therapeutic purposes in various kinds of viral infections. “In the current state of the pandemic, due to the unavailability of approved specific vaccine and drugs for treatment of SARS-Co-V2, an urgent need of therapeutic strategies are required. Human convalescent plasma has not met with the desired results. Pure immunoglobulins obtained from hyper-immune equine sera has been an effective and time-tested approach in various infections such as diphtheria, tetanus, rabies and bites from snakes, scorpions, arachnids and more recently SARS-CoV-1, MERS-CoV, Ebola and avian influenza virus,” the researchers said.

The study provides evidence of the potential of generating highly purified immunoglobulins from equines against SARS-CoV-2 that can demonstrate consistent and high neutralisation activity.

“Further, in-vivo testing for efficacy of this indigenously developed, cost effective product will pave the way to clinical evaluation. Additionally, being a donor independent method, this may prove as an efficient alternative to convalescent plasma for treatment of Covid-19 patients”, researchers said. The technology to develop such antisera from horses is already transferred to Biological E Limited, which is developing the therapeutics.