The American Red Cross is testing all donated blood for novel coronavirus antibodies and will use this information to learn more about the spread of COVID-19. They will also contact donors again to find out how long their antibodies will last.
If someone has antibodies to the novel coronavirus, this is a sign that they have been infected with the virus at a certain point in time. Although the tests on the market are currently not perfect, many people are still interested in getting them – including people who thought they had COVID-19, but couldn't get tested if they were sick.
One goal of the antibody testing initiative is to encourage more people to donate blood, said Susan Stramer, vice president of scientific affairs for the Red Cross. Home orders meant that fewer people than usual had donated blood in the past few months The supplies are running low. Since the start of antibody testing on June 15, the organization has increased the number of donation dates by approximately 150 percent.
If someone donates blood to the Red Cross, they agree to have their blood samples approved for use in research studies. Thousands of people across the country donate blood every month, giving the organization a huge pool of blood samples for analysis. By testing all of these samples for novel coronavirus antibodies, the organization can also get a feel for how widespread the virus is.
"We collect 40% of the country's blood supply, so we have a simple picture to answer questions about how many people are antibody positive," says Stramer. So far, around 1.2 percent of blood donors have novel coronavirus antibodies with two-week data.
The Red Cross will contact donors with antibodies and ask if they would like to take part in an additional follow-up study to test how their antibody levels can change over time. These antibodies are likely to help protect people from re-illness from the virus, but much more research needs to be done. Researchers still don't know exactly how long antibodies to this virus actually stay in the body. Something preliminary data suggests that novel coronavirus antibodies may only stay for a few months, especially in people who have had no symptoms when infected.
The study will check in once a month to retest participants' antibody levels. "We hope to enroll as many people as possible, but I think if we hit 30 percent we would consider it a success," said Stramer.
The Red Cross also takes part a nationwide antibody studywith the support of disease control and prevention centers. This study will involve several blood donation organizations and will review the percentage of the population with novel coronavirus antibodies this fall and again in 2021. "It's certainly the largest serosurvey I've ever been involved in," said Michael Busch, who oversees efforts as director of the Vitalant Research Institute, told science. Each of these surveys will include 50,000 blood samples.
The projects are similar but different in scope. "We are deeply concerned with the details of our donors and the duration of the antibodies, while the CDC program will examine changes over time," says Stramer.
For decades, blood donation centers have used the thousands of samples that are available for scientific research. Studies started by the National Heart, Lung and Blood Institute began in 1989 to examine donations of blood for concerns about the effects of HIV on the safety of blood transfusions. Since then, blood has donated helped scientists understand more about diseases like Zika and West Nile Virus.
Blood donations do not give us a perfect overview of a population. Some groups are also excluded from complete blood donation. Men who have had sex with another man in the past three months are not eligible, effectively eliminating gay men who are not abstinent from donation. The Red Cross also promotes its antibody tests, so sick people may volunteer to donate blood. This could distort the data they collect and weight them more strongly against people with antibodies. The organization interviewed donors to ask why they chose to donate so they have this information to accompany the study.
People also need to be perfectly healthy to donate blood. Because COVID-19 may linger, there may be a time lag between the illness and the count in such studies.
It's still valuable to understand how many people who are currently healthy have novel coronavirus antibodies, says Stramer. "It really represents those people who may not know that they have been infected or who have been infected and are now symptom-free."