Genome sequencing ‘world-leading’

A review has described New Zealand’s genome sequencing effort as “world-leading” — but has found room for improvement in steering the clever technology against Covid-19.

Genome sequencing creates a “genetic fingerprint” of a virus that’s infected a person, and can help public health officials untangle different cases involved in an outbreak through their genetic sequences.

In New Zealand’s first wave of Covid-19, scientists sequenced the genomes of 649 separate cases to reveal nearly 300 different introductions from different parts of the world.

Sequencing proved just as crucial in the August outbreak, helping pick apart Auckland community cases — effectively informing the response to the cluster in real time.

“There were several instances where we were reassured that seemingly unconnected clusters were actually closely linked,” Prime Minister’s chief science adviser, Professor Juliet Gerrard, wrote in a post introducing the just-released review.

“There were other times when the specific mutation in a sequence significantly narrowed the search for the contact tracers.”

The review, carried out by Environmental Protection Authority chief scientist Professor Michael Bunce, noted that half the Covid-19 cases that had received positive PCR tests had been sequenced.

But Bunce found there was a need to build capacity, speed up the delivery and processing of samples, and improve how genomic data is reported.