Vacuum Oven Drying: A Cost-Effective Way of Producing Field-Deployable Reagents for In-house Real-Time PCR Methods.

The polymerase chain reaction (PCR), is a widely used, sensitive and reliable method for detecting pathogens. However, technical limitations may restrict its use outside sophisticated laboratories, e.g.

High secondary attack rate and persistence of SARS-CoV-2 antibodies in household transmission study participants, Finland 2020-2021.

Background: Household transmission studies offer the opportunity to assess both secondary attack rate (SAR) and persistence of SARS-CoV-2 antibodies over time.

Methods: In Spring 2020, we invited confirmed COVID-19 cases and their household members to four visits, where we collected nasopharyngeal and serum samples over 28 days after index case onset. We calculated SAR based on the presence of SARS-CoV-2 neutralizing antibodies (NAb) and assessed the persistence of NAb and IgG antibodies (Ab) against SARS-CoV-2 spike glycoprotein and nucleoprotein.