Test results showed that only one sample had antibodies for COVID-19 and SARS, Academia Sinica Institute of Biomedical Sciences research fellow Lin Yi-ling (林宜玲) said.
The sample was obtained from a Taiwanese businessperson who was not listed as a confirmed case, because their immune system beat the virus, she said.
Little is known about COVID-19, so it is still a mystery whether a person who has recovered from it can contract it again, she added.
The method is useful in tracing the transmission chain of a certain case, Institute of Plant and Microbial Biology Director Wu Shu-hsing (吳素幸) said, but added that testing for RNA viruses tells whether a person contracts COVID-19.
Using molecular biology and genetic engineering, Wu said that she pieced together plasmids — a kind of DNA for expressing antigens — in small templates to make up longer series of plasmids for producing the antigens used to test for COVID-19, SARS and Middle East respiratory syndrome antibodies.
Ordering massive plasmid series from overseas manufacturers takes two to three weeks, Lin said, praising Wu’s team for only needing a week.
After Institute of Biological Chemistry associate research fellow Ho Meng-chiao (何孟樵) purified the nucleocapsid protein of COVID-19 for making reagents, Lin used the western blot method to place the antigens in a serum sample for testing antibody reactions, she said.