Modelling NZ’s Next Omicron Wave Expert Reaction | Scoop News – Scoop

How might waning immunity and reinfection affect our nextwave of COVID-19? Researchers have modelled differentscenarios to predict what the coming months might looklike.

The researchers found that a second COVID wavearose in the latter half of 2022 in all their scenarios,smaller than our first wave and set to peak in August toNovember depending on how fast immunity drops. However, ahigher peak of hospitalisations may occur if more olderpeople get infected. Under a faster-waning immunity scenariowith older ages more infected, this modelling estimates thatas many as 46% of cases could be reinfections.

The SMCasked experts to comment.

Dr Dianne Sika-Paotonu,Immunologist, Associate Dean (Pacific), Head of Universityof Otago Wellington Pacific Office, and Senior Lecturer,Pathology & Molecular Medicine, University of OtagoWellington, comments:

Waning immunity andreinfection

Many whove recovered from Covid-19will have developed immunity at least for the initial monthsfollowing infection, however reinfection risk with theSARS-CoV-2 virus remains. Although previous infection withthe virus does offer some immune protection, this does waneover time. More people have now been exposed to theSARS-CoV-2 virus, and with the emergence of the Omicronvariant, reinfections have been increasing in a way not seenwith earlier variants. Omicrons higher transmissibilityand ability to evade immune protection are likelycontributing factors.

Whats known from overseasstudies on reinfection risk

Towards the end of 2021as Omicron was spreading, data from South Africa was showinghigher reinfection rates when compared with previousinfection waves this pattern was also seen in othercountries. In the UK, the reinfection risk was found to be16 times greater when Omicron was the dominant variant,compared to when Delta dominated about seven months prior.This survey work was undertaken using random sampling ofhouseholds by the UK Office for NationalStatistics.

Data from England has also demonstrateda reinfection increase, where the rate of reinfections ofreported cases in February 2022 was about 10%, jumping fromjust 1% prior to mid-November 2021. One study from Qatar,which looked at the reinfection severity after initialinfection with the Alpha and Beta variants, indicated thatoverall, SARS-CoV-2 re-infections where anotherinfection occurred at least 90 days after the firstinfection tended to be less severe when compared withthe first infection.

Ongoing work will be needed tounderstand more about whether reinfections for Omicron andall its sub-variants are more or less severe, when comparedto the primary infection. It is still important that thosewho may have already had a Covid-19 infection furtherstrengthen their immunity withvaccination.

Overall, current evidence isindicating that reinfections have been increasing with theOmicron variant, and the risk of reinfection with theSARS-CoV-2 virus remains, especially for vulnerablecommunities.

Reinfection risk in NewZealand

Right now the daily reported COVID-19figures are still very high, and continue to place addedstrain and pressure on our health and other support systemsin Aotearoa New Zealand. The actual COVID-19 community casefigures are likely higher than those being reportedcurrently resulting from asymptomatic infection, and themajority of new community cases being detected by rapidantigen testing (RAT) with reliance on self-reporting ofresults. Reinfections in Aotearoa New Zealand will need tobe monitored carefully.

Impact of healthinequities

The COVID-19 pandemic has exacerbatedpre-existing inequities in health for vulnerablecommunities, and this includes for Mori and Pacificpeoples. It was known from the outset that Mori andPacific peoples were vulnerable to being disproportionatelyimpacted and affected by COVID-19 and therefore requiredprioritisation with respect to COVID-19 vaccination,prevention, and testing efforts. Inequities remain evidentwith vaccination and booster levels, and need to beaddressed with equity approaches that build trust and reducebarriers for people. Pacific peoples currently make up 11%of Covid-19 cases and more than double that 27% ofall hospitalisations.

Significant immunity gaps inAotearoa New Zealand exist right now as we move into winter.Children, tamariki and tamaiki aged 5-11 years still need tobe vaccinated against COVID-19 and many people are still toget COVID-19 boosters, with booster doses for the COVID-19vaccine now readily available for 16-17 year olds inAotearoa New Zealand.

Vaccination against otherillnesses

During the COVD-19 pandemic, there hasbeen limited exposure to other viruses such as the influenzavirus here in Aotearoa New Zealand, and there is potentialrisk of upcoming influenza outbreaks moving into winter. Wenow have more of the Influenza vaccines here being madeavailable for people these areimportant.

Lastly, although COVID-19 has been a keyfocus over the past two years, it is important to rememberthat all childhood vaccinations remain important. Regularchildhood vaccine schedules (non-COVID-19) for children,tamariki and tamaiki in Aotearoa New Zealand have beensignificantly affected by the Covid-19 pandemic. As aresult, there is potential risk of outbreaks for whoopingcough, measles and other illnesses that could be prevented.A resurgence of influenza and the respiratory syncytialvirus (RSV) could also possibly occur.

Noconflict of interestdeclared.

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Modelling NZ's Next Omicron Wave Expert Reaction | Scoop News - Scoop