Reports from Covid-19 Modelling Aotearoa
Our Covid-19 modelling influences policy decisions, so we make it publicly available as soon as we can. All of our published work is assessed by our fast and committed peer review team to enable a degree of scientific certainty within the parameters of rapid change.
Modelling the impact of the Omicron sub-variant BA.5 in New Zealand
The BA.5 Omicron sub-variant is able to spread more easily than the previously dominant BA.2 sub-variant due to its immune escape characteristics.
Modelling Aotearoa New Zealand’s COVID-19 Protection Framework and the transition away from the elimination strategy
Covid-19 Aotearoa developed an age-structured model for the Delta variant of SARS-CoV-2 including the effects of vaccination, case isolation, contact tracing, border controls and population-wide control measures. We use this model to investigate how epidemic trajectories may respond to different control strategies, and to explore trade-offs between restrictions in the community and restrictions at the border.
Using mechanistic model-based inference to understand and project epidemic dynamics with time-varying contact and vaccination rates
This model was developed as a policy advice tool for New Zealand’s 2021 outbreak of the Delta variant of SARS-CoV-2 and includes the effects of age structure, non-pharmaceutical interventions, and the ongoing vaccine rollout occurring during the time period studied.
Quantifying the impact of isolation period and the use of rapid antigen tests for confirmed COVID-19 cases
New modelling by Covid-19 Modelling Aotearoa suggests that testing with Rapid Antigen Tests before ending isolation for confirmed cases of Covid-19 would significantly decrease the risk of onward transmission, while allowing many people to isolate for shorter periods.
Modelling the dynamics of infection, waning of immunity and re-infection with the Omicron variant of SARS-CoV-2 in Aotearoa New Zealand
Waning of infection-derived immunity means people become increasingly susceptible to being re-infected with Covid-19 over time.
Estimating Covid-19 border arrival risk in Aotearoa New Zealand
A model to assess the risk of Covid-19 infection among international travellers arriving in Aotearoa New Zealand.
A preliminary assessment of the potential impact of the Omicron variant of SARS-CoV-2 in Aotearoa New Zealand
A report showing the results of simulated outbreaks using a branching process model to assess the potential impact of Omicron in Aotearoa New Zealand.
Effect of vaccination, border testing, and quarantine requirements on the risk of Covid-19 in New Zealand
We use a stochastic branching process model to investigate the risk of border-related outbreaks of Covid-19 and strategies to mitigate this risk.
Technical report: Modelling the August 2021 Covid-19 outbreak in New Zealand
We use a branching process model to simulate the Auckland August 2021 outbreak through to early January 2022, including the effects of increasing vaccine coverage by age group and time.
Preliminary estimates of hospitalisation numbers for the August 2021 outbreak, assuming we stay in Alert Level 4
We use the contagion network model to project case numbers and thus hospital and critical care numbers for the current Auckland outbreak of August 2021, with current vaccination coverage.
‘Phased transition’ to phase transition: The network consequences of reconnecting
We seek to explain and explore how changes to Alert Level restrictions may impact the network of interactions on which Covid-19 is spread.
Estimates of new onset of Covid-like illness, symptomatic population, and testing rates
Using the FluTracking survey data for 2021 up until the week ending 29 August 2021, we can estimate the weekly incidence (new onset) of Covid-19-like symptoms within different age groups and different parts of the country.
Estimates of effects of changing Alert Levels for the August 2021 outbreak
We use an individual-based, Aotearoa-specific Contagion Network Model to simulate the spread of Covid-19 in the community for an outbreak comparable to that detected on 17 August 2021.
Modelling to support a future Covid-19 strategy for Aotearoa New Zealand
Updated modelling exploring how high rates of vaccine coverage might reduce the health burden from Covid-19 if combined with moderate public health measures to reduce transmission of the virus.
FluTracking incidence calculation methods
This report details the methods used for calculating the estimated weekly incidence of Covid-19-like and influenza-like illness in Aotearoa New Zealand, using data from the FluTracking weekly survey.
Contagion network modelling in the first weeks of the August 2021 outbreak
In the first weeks of the 2021 Auckland August Covid-19 outbreak, the contagion network team provided a number of reports to officials with estimates of the likely size of the outbreak and updates on the estimated effect of Alert Level interventions on curtailing spread.
Inter-regional movement and contagion risk analysis August 2021
We use a range of data sources and analytic approaches to estimate the number of movements between regions of Aotearoa and to give some estimates of the risk of transmission of Covid-19 to regions outside of Auckland, during the early stages of the August 2021 outbreak.
Modelling the potential spread of Covid-19 during the August 2021 outbreak
Two technical reports in which we consider the epidemic course for the August 2021 cluster following the shift to Alert Level 4 restrictions in New Zealand, using a stochastic branching process model.
Exploring Covid-19 transmission risk and vulnerability through the Aotearoa Co-incidence Network (ACN)
The Aotearoa Co-incidence Network (ACN) provides a highly insightful tool to explore the manner in which the regions of Aotearoa New Zealand are connected to each other through co-incidence of individuals at workplaces and schools.
Covid-19 network modelling trilogy: Elimination, Alert Level 2.5 and other non-pharmaceutical interventions
Three network modelling reports that explore policy settings and possible interventions to prepare for the emergence of Covid-19, whether Alert Level 2.5 can be effectively used for future outbreaks, and a large number of combinations of transmission reduction interventions.
A Covid-19 vaccination model for Aotearoa New Zealand
We use a mathematical model to estimate the effect of Aotearoa New Zealand’s vaccine rollout on the potential spread and health impacts of Covid-19 and the implications for controlling border-related outbreaks.
Vaccination and testing of the border workforce for Covid-19 and risk of community outbreaks: A modelling study
We use a stochastic model of Covid-19 transmission and testing to investigate the effect that vaccination of border workers has on the risk of an outbreak in an unvaccinated community.
Mathematical modelling to inform New Zealand’s Covid-19 response
We describe the development of a stochastic mathematical model for the transmission and control of Covid-19 in New Zealand.
Modelling support for the continued elimination strategy
Our researchers model the effects of various different border policies and testing regimes for frontline border workers on Covid-19 reincursion risk.
Early intervention is the key to success in Covid-19 control
We assess the importance of early implementation of interventions for controlling Covid-19.
Impact of Covid-19 pandemic on New Zealand research students
Early career researchers provide a valuable contribution to the research ecosystem in Aotearoa New Zealand, but are particularly vulnerable to the fallout from the Covid-19 pandemic.
Economic comparison of the use of Alert Levels 3 and 4 for Auckland’s August outbreak
We compare the economic costs of containing Auckland’s August Covid-19 outbreak using Alert Level 3 to those that might have resulted from the use of Alert Level 4.
Simulations of re-emergence and spread of Covid-19 in Aotearoa
Our researchers simulate the re-emergence and spread of COVID-19 in July/early August 2020, using a network model of all ~5 million people in Aotearoa New Zealand.
Auckland’s August 2020 Covid-19 outbreak – Cabinet advice
This paper summarises the modelling advice provided to Cabinet during the August 2020 outbreak of Covid-19 in Auckland, as well as detailing the methods used to provide that advice.
Likelihood of Covid-19 spreading outside Auckland
Our researchers find that the current effective reproduction number for Covid-19 in Auckland and the likelihood of cases occurring in other regions remains uncertain.
Estimated inequities in Covid-19 infection fatality rates by ethnicity for Aotearoa New Zealand
We aim to estimate inequities in infection fatality rates (IFR) for Covid-19 in Aotearoa New Zealand by ethnicity.
Potential reduction in transmission of Covid-19 by digital contact tracing systems
Our research suggests that Covid-19 contact tracing digital tools such as smartphone apps need to be designed to work hand in hand with manual contact tracing.
Managing the risk of a Covid-19 outbreak from border arrivals
Our researchers estimate the risk of community COVID-19 outbreak originating at the New Zealand border and provide some recommendations for managing future risk.
Successful contact tracing systems for Covid-19 rely on effective quarantine and isolation
Our modeling shows that a high-quality, rapid contact tracing system, combined with strong support for people in quarantine or isolation, can be highly effective in reducing the spread of Covid-19.
Effect of New Zealand border controls on Covid-19 reincursion risk
Our researchers modelled various border control measures and scenarios to assess the risk of Covid-19 re-entering Aotearoa New Zealand from incoming international travellers.
Probability of elimination for Covid-19 in Aotearoa New Zealand
Our researchers estimate there is a 95% probability that Covid-19 has been eliminated in Aotearoa New Zealand after 2-3 weeks with no new reported cases.
Effective reproduction number for Covid-19 in Aotearoa New Zealand
Our researchers use a stochastic model to simulate Covid-19 spread in Aotearoa New Zealand, and report an estimate for its effective reproduction number (Reff) before and after implementation of Alert Level 4.
A structured model for Covid-19 spread: Modelling age and healthcare inequities
Our researchers have developed a structured model to look at the spread of Covid-19 in different groups within the New Zealand population.
New interactive app simulates Covid-19 spread
A new epidemic simulation app shows how powerful our actions are in taking control of Covid-19.
Effect of Alert Level 4 on Reff: Review of international Covid-19 cases
An analysis of interventions used around the world and their effect on the spread of Covid-19 in the context of Aotearoa New Zealand’s Alert Level system.
Estimated inequities in Covid-19 infection fatality rates by ethnicity for Aotearoa New Zealand
How equitable is our healthcare system? Our researchers and colleagues analysed available data to estimate Covid-19 infection fatality rates by ethnicity in Aotearoa New Zealand.
Modelling Covid-19 spread and the effects of Alert Level 4 in New Zealand
Our investigators model Covid-19 containment and elimination scenarios in Aotearoa New Zealand, as the country considers an exit from a four-week period of strong population-wide control measures.
Suppression and mitigation strategies for control of Covid-19 in New Zealand
Our researchers compared the effectiveness of various strategies on controlling the spread of Covid-19 in Aotearoa New Zealand.