NZ’s Covid soup getting messier

• Author: Jamie Morton
• Published date: 25 January 2023
• Publication title: Hawkes Bay Today

There were 79 virus-related deaths, 242 people are in hospital as at midnight on Sunday and seven in ICU

The ministry reported two of the dead were from Northland, 24 from Auckland region, six from Waikato, five from Bay of Plenty, two from Lakes, one was from Tairawhiti, two were from Hawke’s Bay, one from Taranaki, six from MidCentral, three from Wellington region, three from Nelson Marlborough, 12 from Canterbury, two from South Canterbury and 10 from Southern.

One was younger than 10 years old, two were in their 20s, two in their 40s, seven in their 50s, 12 in their 60s, 10 in their 70s, 27 were in their 80s and 18 were aged over 90. Of these people, 50 were women and 29 were men.

The “variant soup” behind New Zealand’s latest COVID-19 wave has only grown more complex, with tricky hybrid strains like the newly arrived Kraken making up a fast-growing chunk of sequenced cases.

While most coronavirus infections last year were caused by a handful of Omicron types — namely BA.2 and BA.5 — ESR’s latest surveillance update showed a diverse mix of lineages was now driving spread.

Case numbers have been slowly dropping towards the 1000-mark after a Christmas bump.

That’s in line with drops in hospitalisations, with just over 400 cases as at the start of the week, but also a rise in reported reinfections, now at about 40 per cent, with the true proportion likely much higher.

BA.5, largely responsible for last year’s winter wave, accounted for only about 9 per cent of cases sequenced over the month to January 13, with CH.1.1 making up roughly a third.

That subtype — a descendant of BA.2, which likely caused most of the country’s first Omicron infections — sported the same genetic mutations as the more recently introduced BQ.1.1, which already accounted for 15 per cent of cases.

Nicknamed Cerberus, BQ.1.1 and fellow BA.5 off-shoot BQ.1 (Typhoon) fuelled a tide of infections in the US and France last year, owing to their ability to better escape immunity from first and booster vaccines.

Also in the mix were BA.2.75, or Centaurus — a second-generation subvariant of BA.2 making up 17 per cent of cases — and a handful of “recombinant” strains created by two viruses swapping genetic material and typically designated with an X.

These include XBF (19 per cent of cases) XBC (4 per cent) and XBB (2 per cent) — and, at present at low levels, XBB 1.5, better known as Kraken.

The World Health Organisation (WHO) has labelled Kraken — now causing large numbers of infections...