An electrochemiluminescence immunoassay, Roche Elecsys® Anti-SARS-CoV-2 (99.5% sensitivity,7 (link) 99.8% specificity;7 (link),8 Roche, Switzerland, was used to identify antibodies in the serological samples. Reactive for optical density (a proxy for antibody titer) cutoff index 1.0 and non-reactive for cutoff index 1.0, according to manufacturer instructions.8 PCR testing of aliquots of Universal Transport Medium UTM) used for nasopharyngeal and oropharyngeal swab collection was utilized to assess current infection (Huachenyang Technology, China).
Aliquots were extracted using the QIAsymphony platform (QIAGEN, USA) and evaluated using the TaqPathTM COVID-19 Combo Kit (100% sensitivity and specificity;9 Thermo Fisher Scientific, USA) on an ABI 7500 FAST (Thermo Fisher, USA). On a Hamilton Microlab STAR (Hamilton, USA), samples were extracted using a custom protocol10 (link) and tested using the AccuPower SARS-CoV-2 Real-Time RT-PCR Kit (100% sensitivity and specificity)11 (link) on an ABI 7500 FAST, or directly loaded into a Roche cobas® 6800 system to be assayed. All laboratory testing was done at the HMC Central Laboratory according to defined procedures.12–15 (link) The laboratory is accredited by the College of American Pathologists.
Aliquots were extracted using the QIAsymphony platform (QIAGEN, USA) and evaluated using the TaqPathTM COVID-19 Combo Kit (100% sensitivity and specificity;9 Thermo Fisher Scientific, USA) on an ABI 7500 FAST (Thermo Fisher, USA). On a Hamilton Microlab STAR (Hamilton, USA), samples were extracted using a custom protocol10 (link) and tested using the AccuPower SARS-CoV-2 Real-Time RT-PCR Kit (100% sensitivity and specificity)11 (link) on an ABI 7500 FAST, or directly loaded into a Roche cobas® 6800 system to be assayed. All laboratory testing was done at the HMC Central Laboratory according to defined procedures.12–15 (link) The laboratory is accredited by the College of American Pathologists.