Covid-19: Blood transfusion from those who have recovered may help
Virus fighting antibodies from people who have recovered from the coronavirus disease Covid-19 can help cure others, according to a research finding published on Tuesday that describes the technique – convalescent plasma therapy – as a promising option to save lives till a vaccine is found.
The therapy, the most distinct among the handful of options doctors around the world have for Covid-19 at present, had consistent and safe effects on a small group of 10 patients in China who were critically ill but began to show significant improvements after a single dose, the American journal Proceedings of the National Academy of Sciences (PNAS) reported on Tuesday. “All symptoms in the 10 patients, especially fever, cough, shortness of breath, and chest pain, disappeared or largely improved within 1 day to 3 days upon CP transfusion,” said the report, which studied the effects of the therapy on severely ill patients with a median age of 52 years.
The study was published without embargo by PNAS because of its potential to save lives. Till Tuesday, the Covid-19 pandemic has killed about 74,000 people across the world.
While efforts to develop a vaccine are proceeding at a record place, doctors are repurposing drugs and therapies with proven safety to minimise fatalities.
The basis for convalescent plasma therapy is simple: plasma – a component of the blood – from a recovered patient carries the specific antibodies that can neutralise the Sars-Cov-2 virus. This is transfused in a patient fighting the infection, acting as reinforcement for the immune system.
For the 10 patients, the results were immediate.
The transfusion raised lymphocyte counts, improved liver and lung function, and reduced inflammation, found the study. Lung lesions and other severe symptoms abated within the next week.
The therapy led to no serious adverse reactions, but the researchers noted a need for larger randomized-controlled clinical trials to establish efficacy across populations.
“It’s an excellent idea, plasma has been used to prevent and treat infections since the 1890s. We still give immunoglobulin IgE serum to prevent rabies in people with animal bites, and varicella-zoster immunoglobulin to pregnant women who have been exposed to chickenpox, which leads to pregnancy complications for the mother and her unborn child. It’s not used for pneumonias and chest infections anymore -- we use antibiotics -- but it was used with success to treat influenza during the Spanish Flu pandemic,” said Dr T Jacob John, professor emeritus and head of the department of virology at Christian Medical College, Vellore, Tamil Nadu.
The US Food and Drug Administration approved the therapy last month to treat Covid-19 patients in the United States, following which several hospitals have begun clinical trials to document its effectiveness.
“The treatment’s success would depend on to whom and when it’s given. It should be given to people at risk, such as those who are old or have diabetes or hypertension, and must be given before complications begin. If it’s given late, it will have little effect,” said Dr John.
Another expert said the therapy had shown promise in treating several diseases.
“The immunisation mechanism has been used against other viral infections with varying success. It lowered viral load and deaths in people with severe acute respiratory infections during the H1N1 (swine flu) pandemic of 2009-10, and improved survival in patients with severe acute respiratory syndrome not responding to treatment,” said Dr G Khilnani, chairman of PSRI Institute of Pulmonary and Critical Care and former head of pulmonology at AIIMS, both in New Delhi.
The World Health Organization recommended its use against Ebola, and issued protocols for its use to treat Middle East respiratory syndrome.
“It’s being used in China and the US and involves a fairly easy procedure, collecting blood, titrating the plasma and injecting it into the patient. But for its use and rapid scale up in India, we need rules to regulate it. Blood banks are licenced and regulated by the Food and Cosmetics Act in India, and unless rules for plasma transfusion are formulated, it cannot be done here,” said Dr RN Makroo, senior consultant, transfusion medicine, Indraprastha Apollo Hospitals, Delhi.
India’s Empowered Committee for Covid-19 Response has fast-tracked approvals of re-purposed drugs to lower severe disease and death till a vaccine is available in 2021, and but it’s too early to say how well re-purposing will work as the outcomes of rigorous tests are yet to come.