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Coronavirus pandemic
OpinionLetters

Letters | Hong Kong Covid-19 mass testing: why fears of DNA collection are unfounded

  • Contrary to the conspiracy theories being peddled, Covid-19 testing involves short sequences of RNA, not DNA. Gene-sequencing technology has not yet progressed to the point where a person’s whole genome can be captured quickly and cheaply

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A technician in a protective suit processes RT-PCR Covid-19 tests at a laboratory in Hong Kong on July 31. Photo: Bloomberg
Letters
With Hong Kong’s mass Covid-19 testing soon to be in place, concerns among the public over how the biological information will be captured and processed have led to privacy worries. I was astonished to find that lawmakers and professionals in the diagnostic industry were offering conspiracy theories about the test without substantial scientific evidence.

Currently, a Covid-19 test can be performed using antibody- or nucleic acid-based approaches. The nucleic acid-based approach applies a laboratory technique called real-time polymerase chain reaction (RT-PCR) to test for the presence of viral RNA (ribonucleic acid) – a genetic piece of Covid-19 – in a deep-throat saliva sample or a nasopharyngeal swab.

The RT-PCR test specifically amplifies a short region on the RNA sequence of the Covid-19 virus. If a viral RNA sequence is detected in the sample, the amplification is successful and presented as positive, or “+”. No DNA sequences are revealed by this test.

The allegations against mass Covid-19 testing suggest that genomic or DNA information would be captured and transferred for different applications, like biometric tracking or producing a DNA mugshot that allows facial reconstruction. Those who make such allegations must know very little about whole genome (DNA) sequencing (WGS) and genotyping.

03:07

Hong Kong’s mass Covid-19 testing to begin on September 1, to last at least 7 days

Hong Kong’s mass Covid-19 testing to begin on September 1, to last at least 7 days

A human genome is a long stretch of combinations of four DNA letters – A, T, C and G – running to 6.4 billion letters in all. Thus, sequencing a whole genome (WGS) – as opposed to a short strand of RNA – is a much more complex and expensive undertaking.

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