NEW YORK ─ A Danish team has partnered with Unilabs on a study that will use antibody testing to determine whether COVID-19 patients have gained immunity, as well as the extent to which healthcare workers have been exposed to SARS-CoV-2, the virus that causes the disease.
The study involves hospitals in the Greater Copenhagen region and is being spearheaded by researchers at Copenhagen University Hospital, the Copenhagen University Biobank, and Herlev and Gentofte Hospital. Unilabs Denmark, the local subsidiary of the European diagnostic services provider, will carry out antibody testing as part of the effort.
Henrik Ullum, a professor of clinical medicine at the University of Copenhagen, said that the work will be used to gain information about sustained antibody response to SARS-CoV-2, as well as to inform prevention measures in the healthcare setting in Denmark.
"The whole idea is to find out how heavily exposed the staff at the hospitals are in general and what functions are related to increased risk of COVID-19 infections," said Ullum. The study has been designed with multiple stages of screening relying mainly on the Wantai SARS-CoV-2 Immunoglobulin M and total antibody ELISA manufactured by Chinese diagnostics maker Beijing Wantai Biological Pharmacy, a test that Danish health authorities procured in bulk.
Ullum noted that the researchers have validated many commercial enzyme-linked immunosorbant assays for SARS-CoV-2, and that the Wantai product has "performed well in regards to sensitivity and specificity." The researchers tapped Unilabs to help them test at scale.
"The reason we work with a private company is to do this at capacity," said Ullum. "They are testing part of our samples.
This month, Unilabs announced that it would test 15,000 blood samples for antibodies as part of the project. All hospital staff who had contact with patients in Greater Copenhagen may be tested for free. There are three rounds of testing. The partners are currently engaged in the second phase. A third round will commence in the fall, when health experts predict another wave of the pandemic.
According to Ullum, the screening is supported by the Greater Copenhagen Hospital System and the corresponding research is supported by the Lundbeck Foundation in the form of a DKK 10 million ($1.6 million) grant. At each round, around 40,000 healthcare employees will be invited to take part.
In addition to generating antibody response data, researchers will also obtain clinical information from the state-run Danish Health Platform, which offers access to health records dating back decades, as well as questionnaires. The results of the study will be compared to Danish blood donors, who will serve as a control population. Researchers are particularly interested in whether healthcare workers have a sustained immune response to the virus that may protect them from reinfection, as well as how many might be infected at any time.
"The reason we are testing hospital staff is to find out how exposed they are compared to the rest of the population," said Ullum. "In the early phase of the epidemic in Denmark, there was a lack of protection, face masks were lacking and such," he noted. "Some of the regulations on wearing masks were adapted based on the number of masks available," he said. There is also the issue of asymptomatic carriers, compounded by some of the unreliable diagnostics that were used early on to test for the disease. By screening healthcare workers over time, he and fellow researchers will be able to see who actually has antibodies to the virus, and if newly implemented prevention measures are working to contain it.
Testing will continue through autumn, followed by the publication of some preliminary results. Another round of testing might take place in 2021. "We expect a prolonged epidemic in Denmark because seroprevalence is low," said Ullum. "We are no way through this epidemic."
According to the World Health Organization, there have been about 13,000 confirmed cases of COVID-19 and more than 600 deaths in Denmark, which has a population of about 5.8 million.
Ullum noted that Denmark has some advantages in carrying out such a longitudinal study, given its centralized, online electronic health records system. "In Denmark, we all have personal registration numbers, and so, we are in a good position to determine how protective antibodies are because we can follow large populations over time," Ullum said.
For Unilabs, one of Europe's largest diagnostic service providers, the collaboration with the Danish researchers is a small but notable piece of a larger response to the COVID-19 pandemic one that has transformed the company since it began earlier this year.
Alistair Hammond, global director of communications for the Geneva, Switzerland-headquartered company, noted that Unilabs is operational in 17 countries and recently announced it has tested a million people for SARS-CoV-2 using PCR since the pandemic began. Antibody tests are not far behind. Hammond said that Unilabs has done around 500,000 antibody tests and is now ramping up antibody testing across the Unilabs Group.
PCR and antibody tests have been the standards for Unilabs, he noted, though the company uses a variety of products to carry out the testing. "No one to my knowledge is doing next-generation sequencing in this group," Hammond said.
That kind of scale-up is apparent across all of Unilabs subsidiaries, including Unilabs Denmark. Peder Andresen, head of international development for pharma services at the company, said that the pandemic, in general, has had a "massive impact on many companies working in the clinical area," including Unilabs.
"We have ramped from doing zero testing in March to now offering several hundred thousand PCR tests a week and probably half the volume of antibody testing on a weekly basis," said Andresen. "It has transformed us and it has been a significant new challenge to an organization that has stepped up to make that transformation possible."
Yet Unilabs, which regularly partners in clinical trials with pharmaceutical companies, might have had a leg up on making that transition. Andersen, who is based in Copenhagen, noted that the company has expertise in data collection, analyzing samples, and reporting the data back to investigators, regardless if they are in an institution or a pharmaceutical biotech company. The samples in the current study will be run at the company's facility in Copenhagen.
Dale Shelton, director of business development at Unilabs Denmark, said that while the study with the Danish researchers is "just a small part" of Unilabs' COVID-19 response, it has the potential to have a wide-ranging impact on research into the disease.
"I think in a perfect world, the investigators would like to see their healthcare workers weren't put further at risk and ideally they would be able to see you do have a sustained response to infection," said Shelton. "I think that would be of great interest, not just to the Danish healthcare workers but to people who are doing research on COVID-19, immunity, and vaccine research."
"The benefit from testing in stages will be to see if there is a sustained antibody response for those who are positive in the first round," noted Andersen. "They will be able to see that in the data, hopefully. That is the idea," he said. Andersen noted that the WHO's current position is that one infection does not guarantee immunity. Yet the Danish study could shed more light on antibody response over time.
"There is an antibody response that will help you get over the virus, hopefully, but they don't know if it's a sustained response or not," said Andersen. None of Unilabs representatives ruled out undertaking similar partnerships in other affected countries where it has a presence. Yet Denmark has some attributes that make such a study worthwhile, Andersen noted. "On the data side, this population is easily accessible and it's easy to get informed consent, as well," he said.