Unlike the few drugs such as the steroids dexamethasone and hydrocortisone that have been found to be effective against Covid-19 monoclonal antibodies can be given to patients much earlier in the course of the disease, stopping them ending up in hospital.
They may also be used prophylactically, meaning they could be given to health workers, those in high risk groups or people known to have come into contact with an infected person.
However, they are also expensive and difficult to produce, sparking fears they may be out of reach for the world’s poorest people.
Earlier this week the leaders of the UK’s Recovery trial, who have been at the forefront of the global search for effective Covid-19 treatments, said they would include two monoclonal antibodies developed by US drug firm Regeneron in their study.
Dr Nick Cammack, who is leading the global search for coronavirus therapeutics at UK biomedical research charity Wellcome, told the Telegraph last month there was a lot of excitement at the prospect of monoclonal antibodies.
“These are the first absolutely specific treatments for Covid-19. We’re excited about them and we think they will work,” he said.
Mononcal antibodies “fast forward” the body’s immune response to the disease and prevent it from going into the immune system overdrive that can kill patients.
Antibodies only have to be harvested from a recovered patient once as the cells can be grown an infinite number of times.
Daniel Altmann, professor of immunology at Imperial College, who was not involved in the study, said the findings were an “impressive step forward”.
“From the start of the pandemic, immunologists have worked to produce potent, virus-neutralising monoclonal antibodies as a therapeutic that could be given to block and limit infection. While many of us had thought of this as a possible ‘emergency’ option in an intensive care setting, this study shows that it has value and application in milder cases, reducing the chance of progression to a need for hospitalisation.
“A joy of this approach is that one can really fine-tune monoclonal antibodies, to the best possible neutralising action against the virus. A downside is that this is hard to roll-out as a widely accessible, affordable option.”