‘Increasingly likely’ Aotearoa will see a ‘significant’ Covid wave before year ends

It is looking “increasingly likely” that New Zealand could see another “significant” wave of Covid-19 before the end of the year, a leading modeller says.

A raft of new subvariants look to be driving an upward trend in parts of Europe, Covid-19 Modelling Aotearoa and University of Canterbury Professor Michael Plank said.

While these were circulating at relatively low levels still, they seemed to be independently acquiring similar sets of mutations and a potential growth advantage, allowing them to escape some population immunity.

At the rate some were growing – such as BQ.1.1 – these could spark another wave, Plank said.

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If that happened, given the border was open, New Zealand would follow behind “within weeks”, and Aotearoa should look to get updated Omicron booster vaccines “sooner rather than later”, Plank said.

The situation overseas was different from previous waves, which were clearly caused by a single variant, he said – pointing to New Zealand’s February/March BA.2 and winter BA.5 wave as an example.

There was a “large number” of newer Omicron subvariants cropping up and quite a bit of uncertainty as to which in the “alphabet soup” would turn out to be the winner.

Scientists were keeping a “very close eye” on BQ.1.1, which “seems to have the edge” and was growing fastest.

However, this was based on a relatively small number of sequences and not always representative of what was happening in the community, Plank said.

International experts have estimated the subvariant could have a growth advantage of at least 10% per day over BA.5, which they believed could drive a variant wave in Europe and North America before the end of November.

Plank said it was certainly possible that a BQ.1.1 wave – or future Omicron wave – could be “as big” as previous BA.2 and BA.5 waves in New Zealand if it was to take off here.

But it was very early days and it wasn’t clear yet what the impact of a wave of one of these new Omicron subvariants could be in terms of hospitalisations or severe illness, he said, particularly given the level of population immunity we had.

He said people who previously had Omicron were likely to be at lower risk of severe illness in a future wave, so hopefully the impact of such an outbreak could be “blunted” by that.

However, any new significant wave had the potential to cause “significant disruption” with people off sick and add “significant pressure” to the health system.

Coming into summer would work in our advantage.

Whereas it was getting colder in the Northern Hemisphere and people were moving indoors – “adding fuel to the fire” – Kiwis would be spending lots more time outside towards the end of the year and the health system typically wasn’t as busy as in winter.

Plank said it would be “good to see” updated Omicron bivalent vaccines available in New Zealand, as those gave people a “slightly higher level” of protection against currently circulating variants.

Medsafe has received an application for the Pfizer BA.1 Omicron-specific booster, but not yet for the BA.5 booster.

Until these were available, Plank recommended anyone eligible for a Covid-19 vaccine booster who hadn’t done so to get one.

“Vaccination is by far and away the best tool we have, so it’s important we maximise the benefit we get from that.”

BA.5 remains the country’s dominant subvariant – accounting for an estimated 91% cases currently.

In the two weeks ending September 16, variants BA.5, BA.4, BA.4.6 and BA.2 (including BA.2.75 and BA.2.75.2) were detected in community samples, a trends report published on Monday showed.

The Ministry of Health has been contacted for comment.