UMMS Affiliation

Program in Molecular Medicine; Medical Scientist Training Program; Department of Biochemistry and Molecular Pharmacology; Graduate School of Biomedical Sciences

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Document Type



Epidemiology | Health Services Administration | Health Services Research | Immunology of Infectious Disease | Immunopathology | Immunoprophylaxis and Therapy | Infectious Disease | Microbiology | Virus Diseases


It is breathtaking to consider how the response to pandemic viral pathogens has been transformed over the past century by greater knowledge of fundamental biology and technological innovations including PCR and next-generation sequencing. In striking contrast to the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, the pathogen responsible for the 1918 influenza pandemic was not identified until years after the outbreak. The definitive text in 1927 described influenza as “an epidemiologic conception” likely caused by the bacterium Haemophilus influenzae. Six decades later, HIV-1 was discovered within a few years of the first report of AIDS, although it took another decade before HIV-1 RNA detection methods were sensitive enough to correlate viral load during clinical latency with rate of progression to AIDS. Four decades later, the genomic sequence of SARS-CoV-2 was publicly available on the internet within weeks of the unexplained outbreak of fatal pneumonia that is now known as COVID-19. This critical information enabled academic researchers, vaccine manufacturers, diagnostic laboratories, and some governments to spring into action. In the midst of COVID-19 lockdown, despite collapse of reagent supply chains, independent investigators around the world shared expertise and reagents in order to establish desperately needed local screening programs for SARS-CoV-2. A paper by Yang et al. in PNAS describes the analysis of viral load data from one local screening program, the results of which have important implications for efforts to control the spread of SARS-CoV-2 and for understanding the pathogenesis of SARS-CoV-2 infection.


SARS-CoV-2 infection, COVID-19, screening programs, diagnosis, PCR, viral loads

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Copyright © 2021 the Author(s). Published by PNAS. This open access article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND).

DOI of Published Version



Silverstein NJ, Luban J. Lessons from a local effort to screen for SARS-CoV-2. Proc Natl Acad Sci U S A. 2021 Jun 29;118(26):e2108044118. doi: 10.1073/pnas.2108044118. PMID: 34140338; PMCID: PMC8255953. Link to article on publisher's site

Journal/Book/Conference Title

Proceedings of the National Academy of Sciences of the United States of America

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Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.