A highly accurate COVID-19 antibody test could soon be used to determine the prevalence of the virus in the Cayman Islands.
Health City has a Roche analyser machine, which is approved by Public Health England, and the hospital hopes to begin a testing programme within the next week.
The tests detect if virus-fighting antibodies are present in the blood – a sign that a person has had COVID-19, recovered and developed a degree of immunity.
Shomari Scott, director of business development at the East End hospital, said the tests could be used to establish how many people had contracted the virus without even knowing it.
“A lot of times you hear people saying, ‘I had the worst flu ever in December, I think I had it’ or ‘January I couldn’t breathe, I know I had it’,” he said. Establishing if that is the case is not just a matter of curiosity.
Scott said identifying past infections of COVID-19 could help inform decisions about how and when different sectors of the economy open up and may even allow for a controlled resumption of tourism.
“What antibody testing will do is allow us to figure out how and when we open up our borders,” he said.
The extent to which antibodies confer immunity is still a developing area of research. Initially, the tests are more likely to be used as a ‘data point’ for government, Scott said.
Eventually, he believes, they will provide a ‘golden ticket’ to travel for people who have had the virus.
Fast test results
Dr. Binoy Chattuparambil, clinical director at the East End hospital, said the process involves a simple blood test that can produce a result in 18 minutes. Health City will have capacity to test 500 people every day.
He said the antibody tests could be used in combination with the Polymerase Chain Reaction tests currently being carried out across the Cayman Islands.
Those PCR tests can only establish if someone currently has the virus. The Roche test will determine if a person has COVID-19 antibodies, which could potentially be from either a past or current infection.
Using the two tests together will allow health officials to determine if the spike in antibodies is from an active or previous infection, according to Dr. Dhruva Kumar, medical director at the hospital.
The distinction is critical because the viral-fighting antibodies, which target the coronavirus and potentially bring protection against re-infection, take longer to develop. Only those with antibodies from past infection would be potentially immune to the virus.
Roche test ‘100% accurate’
Though there were initial concerns about the accuracy of the first wave of antibody tests that came on the market, Public Health England has declared the Roche test to be “100% accurate” based on its own analysis.
“This is a major breakthrough in the COVID-19 scenario,” said Chattuparambil. In the absence of a vaccine, he believes this type of testing is the best way to help release communities from lockdown.
“Definitely, that is the way forward because the world cannot shut down like this for long,” he said.
He believes “antibody passports” will ultimately be issued to allow people to travel who have had the virus and developed immunity.
Another intriguing development is the potential for people who have recovered from the virus to share antibodies with critically-ill COVID-19 patients through blood plasma transfusions.
Health City has the capacity to do this treatment, which has proven successful in limited trials, and is exploring this as a possible treatment option, if it becomes more widely approved.
The antibody testing is expected to begin within the next week, subject to local regulatory approval. Chattuparambil said he did not expect this to be a major hurdle, given that UK public health officials have endorsed the tests.
Professor John Newton, national coordinator of the UK coronavirus testing programme, told the UK’s Daily Telegraph newspaper that experts at Public Health England’s labs had evaluated the test and confirmed the 100% accuracy.
“This is a very positive development, because such a highly specific antibody test is a very reliable marker of past infection,” he said. “This in turn may indicate some immunity to future infection, although the extent to which the presence of antibodies indicates immunity remains unclear.”
One interesting subplot that the new tests may reveal is whether or not Health City, in fact, did have the first coronavirus case on island, as has been widely reported. That case involved an Italian cruise ship passenger who was taken to the hospital after suffering a double heart attack and later died from COVID-19.
With a high number of asymptomatic cases now being recorded, Scott believes it is possible that the virus was on the island before this case.
“Proportionately, there are a lot of positives that have been flying in,” he said. “It would be a little bit strange that only happened after the border closure.”
How it works
- Health City already has a Cobas E411 analyser machine, manufactured by Swiss pharmaceutical company Roche.
- It can be used to detect whether virus-fighting antibodies for a variety of diseases are present in a patient’s blood plasma.
- Roche recently developed the Elecsys Anti-SARS-CoV-2 test, which allows doctors to use the machine to test for coronavirus antibodies.
- It involves taking a small blood sample and running it through the machine.
- If antibodies are present, they are illuminated through a chemical process known as quantitative electrochemiluminescence.
- While scientists expect the presence of antibodies to bring some level of immunity, it is not yet 100% clear that the same person could not contract COVID-19 twice.