Seropositivity to SARS-CoV-2 among asymptomatic blood donors in New York

By Angela Betsaida B. Laguipo, BSNOct 23 2020

The coronavirus disease (COVID-19) pandemic is actively spreading across the globe, and has now infected more than 41 million people, and has claimed over 1.1 million lives. The United States reports the highest number of cases, topping at least 8.4 million.

New York was the hardest-hit U.S. state during the peak of the outbreak in the country. Now, a team of researchers from Serimmune Inc, Santa Barbara Cottage Hospital, and the New York Blood Center aimed to determine the prevalence of seropositive people for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, among healthy blood donors. Their study appears in the pre-print journal medRxiv*.

Study: Prevalence of antibodies to SARS-CoV-2 in healthy blood donors in New York. Image Credit: Kateryna Kon / Shutterstock

*Important notice: medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.

The study

Though the number of cases is skyrocketing across the globe, there is ample evidence for the existence of asymptomatic carriers of SARS-CoV-2. This means that the numbers of those infected could be much higher than reported. The team wanted to see how many people carry antibodies against the virus to see how many potential convalescent plasma donors there might be.

To arrive at the study findings, the researchers analyzed blood samples from more than 1,500 healthy blood donors collected in New York between March and July 2020 for the presence of antibodies to SARS-CoV-2.

With the use of novel technology, SERA (Serum Epitope Repertoire Analysis), the team noted a marked increase in SARS-CoV-2 seropositivity rates over the four months, from 0 percent in March to 11.6 percent in July.

To validate the findings, the team conducted a follow-up enzyme-linked immunosorbent assay (ELISA) test. The test conducted confirmed the results of the previous test.

The researchers said that the current study is consistent with other seroprevalence studies conducted in the greater New York metropolitan region, with reports that COVID-19 infections can be asymptomatic or may only cause mild symptoms.

With the study results, the team hopes that testing for seropositivity among healthy people may show those who have developed antibodies to fight the infection. They could donate convalescent plasma to those currently battling the infection, particularly those admitted to the intensive care unit due to severe illness and complications.

“Our results raise the question of whether a larger number of convalescent plasma donors could be identified among healthy, asymptomatic donors,” the team wrote in the paper.

“However, there is concern about providing antibody results to blood donors without an improved understanding of their immunological significance. We also demonstrate the utility of SERA for monitoring the antibody response to emerging infections,” they added.

What is convalescence plasma therapy?

Convalescence plasma therapy uses blood from people who have recovered from an illness to help others recover. It is performed by obtaining plasma from people who recovered from SARS-CoV-2 infection and then infused to severely or critically ill patients to boost their immune systems to fight the infection.

The U.S. Food and Drug Administration (FDA) authorized convalescent plasma therapy for people with COVID-19, allowing its use during the pandemic while there is still no approved treatment for the infection.

The FDA has issued new guidance in September to provide recommendations to health care providers on the use of COVID-19 convalescent plasma under the investigational convalescent plasma during a global health emergency.

The regulatory body released guidance that provides recommendations on the pathways for the use of the investigational convalescent plasma, the collection of convalescent plasma, compliance with the requirements of using the treatment, and record-keeping.

Many countries are experiencing second wave outbreaks as restrictions are eased. With the winter and cold season coming in the northern hemisphere, scientists and health experts expect the cases to soar. Convalescence plasma therapy may show promise as a method to reduce mortality among COVID-19 patients.

*Important notice: medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.