British companies are being held up in their work to create antibody tests for the coronavirus because they cannot access enough blood samples from patients who have recovered from the disease.
Antibody tests will be crucial to identifying people who have had Covid-19 and have developed sufficient immunity to return to work, but firms working on the tests need samples of convalescent blood to develop the tests and check they are accurate.
“Access to patient samples has been a longstanding issue for the industry and that is highlighted now when companies desperately need them,” said Doris-Ann Williams, the chief executive of the British In Vitro Diagnostics Association. “We need to find a rapid process to allow access otherwise we can never move forward with development and validation.”
Public Health England (PHE) has distributed some supplies of blood that are positive for antibodies against coronavirus, but it has not been able to meet demand. Given the pressure the agency is under, researchers at Oxford University, who are spearheading the UK effort to validate antibody tests, have sourced blood from recovered patients themselves.
Prof Karol Sikora, the chief medical officer at Rutherford Health, expects to receive 1,000 antibody tests from South Korea on Thursday which will be used to test staff working with cancer patients. He said PHE was meant to send blood test panels to labs that would check the tests, but when he tried to contact the agency he got no response.
The shortage of blood samples from recovered patients is affecting research across the board, from government to academia and biotech companies. One reason is that recovered patients with long-term antibodies against the virus are only now emerging, as the epidemic is still in its infancy in the UK.
The body’s first immune response to the virus is a rush of antibodies called immunoglobulin M, or IgM, but these fade away after a few weeks. About a month after the infection starts, the first wave of antibodies are replaced by a more enduring variety, IgG, which it is hoped will protect people for many months and possibly years. It is these that most tests look for.
“People can have two weeks of disease and then three weeks to mount this antibody response, but if you look back five weeks or so there was hardly anyone in Britain with the disease,” said Prof John Bell, the head of the Oxford team.
Dr Yvonne Doyle, the medical director at Public Health England, said the government wanted as many labs as possible to help scale up the UK’s testing capacity, and she called on firms that wanted to help to contact the Department of Health.
She said PHE had only “a very small number” of positive blood samples, because it took time for patients to build an immune response. “For most people infected in the UK, this will have been in the past six weeks and so their blood is only now reaching maturity to be used in this capacity.”
One issue the Department of Health has been urged to look at is whether blood can be obtained from hospital patients who have built up sufficient antibodies. Under existing regulations, blood can only be taken with ethics approval and consent, but this is not often feasible. “These regulations are not there to keep bureaucrats in jobs, we should be able to get round these problems,” said Sikora.
Bell said a new mechanism that had been put in place with NHS Blood and Transplant should provide more positive blood samples for testing work in the coming weeks. Under the scheme, people who have tested positive for Covid-19 in the NHS will be contacted and asked to give blood. Some of this will be used in trials to investigate whether plasma that is especially rich in antibodies can help severely ill patients and protect care workers, while less potent plasma can be used for antibody test development and validation.
“There are going to be lots of units of plasma that don’t quite make the cut but are still positive that you can use for antibody work. People just need to put their seatbelts on and wait for that to come,” he said.
“Everyone expects Public Health England to fix their problems but they don’t have the capacity,” Bell added. “One of the problems with being PHE is you have an easy life until there’s a pandemic and then everybody blames you for everything.”
