New Zealand has been in a COVID lull for the past two months, but with the BA.5 variant on the rise and more than 10,000 new daily cases reported this week, it appears we are now at the start of a second Omicron wave.
How large it will be is difficult to predict, but a number of factors coincide to make this the most serious moment in the pandemic this year since the first wave in March.

BA.5 is the latest instalment in the Omicron series. It was first detected in South Africa in February 2022 and is closely related to BA.2, the variant currently still dominant in New Zealand.

It carries distinct mutations in the spike protein, two of which are associated with higher transmissibility and immune evasion. The rise in BA.5 seems to stem from its ability to infect people who were immune to earlier variants, but so far there is no indication the variant causes more severe disease.

BA.5 was first detected in the New Zealand community in April and cases have been appearing consistently since May. It has quickly risen to 32% of sequenced community cases and looks set to become the dominant variant in the next week. It already is dominant in other countries.

Our recent modelling showed a second wave of COVID this year was likely as a consequence of waning immunity, but the spread of BA.5 has hastened its arrival.
What to expect
A big concern at the moment is that case numbers in older age groups are higher now than ever before. The March wave was heavily concentrated in younger people, with under 60s making up 91% of all cases up to the end of April.

That helped keep a lid on the hospitalisation rate and has built strong hybrid immunity, acquired from both infection and vaccination, in these groups. But it leaves a large susceptible population in older groups.

Read more: https://theconversation.com/a-new-omicron-wave-is-upon-new-zealand-with-older-people-now-most-at-risk-heres-what-to-expect-186394