Protocols and Lessons Learned from Healthy Davis Together
Healthy Davis Together (HDT) has been cited by The New York Times as one of the most ambitious COVID-19 response programs in the country, in part because of our community-wide free testing program for both asymptomatic and symptomatic individuals. Mass testing at scale has been an anchor of HDT since its inception in Spring 2020. We knew that identifying positive cases and quickly mobilizing quarantine support and contact tracing efforts would be key to stopping the spread.
Determining the best testing approach – one we could scale and that was easy for users – was the first step. The gold standard testing approach, PCR clinical tests, was highly effective but its high cost, together with limited supply of reagents, materials and kits for swab testing prohibited the kind of scale we needed. Instead, UC Davis Genome Center implemented the Array Tape-based IntelliQube PCR System from LGC Biosearch Technologies to develop a relatively inexpensive, rapid turnaround, high throughput saliva direct COVID-19 test.
UC Davis scientists took this instrument, designed for high throughput genotyping used in agricultural genomics, and developed a PCR protocol for testing SARS CoV-2. The “spit test” uses saliva and sample collection is quick and painless. This is important since HDT encourages people to get tested at least once or twice weekly. We knew if the process was painful (which the nasal swab can sometimes be), people wouldn’t come back.
In the lab, we made our processing workflow efficient using robotics, allowing us to process the samples quickly and safely – with results delivered within 24-48 hours. And because the IntelliQube PCR System was originally designed as a genotyping instrument, we were quickly able to add rapid genotyping of all positive samples to our protocol – allowing us to detect and monitor variants of concern.
As officials and public health experts consider lessons apply to future pandemic preparedness efforts, we believe saliva-based testing is a scalable approach to consider. Our protocols can be found here, and more about our approach – including steps to implement community-wide testing – can be found in our Blueprint for Community COVID-19 Testing.