IPWEA NZ CONFERENCE 2020 DUNEDIN

Eliminating COVID-19: The NZ experience and future implications

Professor Michael Baker

University of Otago, Wellington Previous experienced with ‘pandemics’ • HIV/AIDS 1987-91 - NEP • SARS 2003Otago (minimal Wellington photoimpact in NZ) • Pandemic influenza (H1N1) 2009 • COVID-19 2020 ‘white knuckle ride’ Outline • Assessing pandemics • Strategic choices for a pandemic response • Components of COVID-19 elimination strategy • Impact of the elimination strategy • Areas of uncertainty & Alternative views • Key lessons from the COVID-19 response Assessing Pandemics

Epidemic (more than expected)

Outbreak (localised) Pandemic (widespread) Assessing pandemics

Factors influencing response to pandemics, include: • Transmissibility of pathogen – Ro, Reff • Severity – particularly case fatality risk (CFR) & infection fatality risk (IFR) • Inequalities – impact of pandemic & response • Controllability – effectiveness of interventions • Feasibility of response – public sector capacity to respond, public acceptability & adherence • Economics – cost of action and inaction, counterfactuals • Certainty - availability & quality of information, science capacity, awareness of options, experience/dogma Assessing pandemics

Estimated mortality from COVID-19 pandemic: • Modelled, assuming Ro=2.5, 25% control • 57% population infected • Peaks after 5 months – 1650 in ICU • 28,300 hospitalised (0.6% population) • 12,700 deaths (0.3% population) = mortality of 25 seasonal influenza seasons • 1918 influenza pandemic = 9,000 deaths (0.8% population)

Source: Wilson et al, 2020. CovidSIM SEIR model with compartments for: susceptible [S], exposed [E], infected [I], and recovered/removed [R] Assessing pandemics

Mortality rates for Māori vs non-Māori in 3 successive influenza pandemics

Source: Wilson et al 2012, Emerg Infect Dis Strategic choices for pandemic response: Light-bulb moments

Source: Wu et al. 1. January 2020 - It’s a serious global pandemic Lancet 31 Jan 2020

2. February 2020 - It can be contained/eliminated

3. March 2020 - NZ is not ready, ‘lockdown’ needed

Source: Aylward et al, WHO, 28 Feb 2020 Strategic Choices for Pandemic Response A. Control – Disease rates reduced to an acceptable level • Mitigation – Manageable levels to avoid overwhelming health system, eg pandemic influenza • Suppression – Low levels to minimise adverse health effects, eg HIV/AIDS B. Elimination – Disease or infection incidence reduced to zero in a defined area (country or region), eg poliomyelitis, measles, rubella • Eradication – Infection reduced to zero at a global level, eg smallpox

Source: Dowdle, MMWR Supple. December 1999 / 48 (SU01);23-7 Strategic Choices for Pandemic Response

Mitigation strategy • Pandemic influenza plan • Aims to ‘flatten the peak’ • Used by NZ for COVID-19 up until mid- March • Used in Europe & North America as ‘Herd immunity’ • Many switched to Suppression strategy

Ministry of Health. 2017. New Zealand Influenza Pandemic Plan: A framework for action (2nd edn). Wellington: Ministry of Health. Strategic choices for pandemic response

Elimination strategy • Developed for COVID-19 in NZ in Feb-March 2020 • Effectively adopted by NZ Gov on 23 March with decision to pursue rapid lockdown with ~100 COVID-19 cases, no deaths

Source: Baker, Kvalsvig, ... Wilson, NZ Med J, 3 April 2020 Components of elimination strategy Components of elimination strategy

1. Exclusion of cases • Keep it out – Border Management 2. Case and outbreak management • Stamp it out – Testing, contact tracing, isolation/quarantine 3. Preventing community transmission • Reducing contacts – Physical distancing & travel restrictions • Reducing transmission per contact – Hygiene measures, masks

Source: Baker et al 2020, NZ Med J, MJA Elimination: Border Management

Arrivals to New Zealand, by day of border crossing, January-June, 2019-20 35000

30000

25000

20000

Number 2019 - A 15000 2020 - A

10000

5000

0

1-Jan 6-Jan

4-Jun 9-Jun

5-Apr

5-Feb

1-Mar 6-Mar

5-May

11-Jan 16-Jan 21-Jan 26-Jan 31-Jan

14-Jun 19-Jun 24-Jun 29-Jun

10-Apr 15-Apr 20-Apr 25-Apr 30-Apr

10-Feb 15-Feb 20-Feb 25-Feb

11-Mar 16-Mar 21-Mar 26-Mar 31-Mar

10-May 15-May 20-May 25-May 30-May Jan Feb Mar Apr May Jun Source: Stats NZ Elimination: Testing & Contact Tracing

Source: MoH website

Swabbing for Covid-19, Wellington, May 2020 Elimination: Physical distancing (lockdown) Elimination: Hygiene measures

Traditional infectious disease hygiene: Te Papa Face Mask • Stay at home if sick • Wash your hands • Respiratory hygiene: cough & sneeze into tissue/elbow

COVID-19 transmission: • Asymptomatic & presymptomatic source • Respiratory droplets and aerosols -> MASKS (Mass Masking = source control & some personal protection) Elimination: Physical distancing (lockdown)

NZ= 96.3

Aust=75.9 Main motorway into Wellington, Alert Level 4, May 2020 Impact of Elimination Strategy Simulated and actual daily numbers of new local and imported cases (confirmed and probable). Effective reproduction number (Reff) • Prior to lockdown: Reff 1.8 (best-fit to case data) • Level 4 Reff = 0.35 (best-fit) • Level 3 Reff = 0.95 (assumed) • Level 2 Reff = 1.7 (assumed)

Source: Rachelle Binny, et al, TPM Impact of Elimination Strategy

Source: Baker, Wilson, Anglemyer. NEJM e56 DOI: 202010.1056/NEJMc2025203 Impact of Elimination Strategy

• 649 SARS-CoV-2 whole genome sequences representative of global virus diversity • 245 separate introductions of the virus out of the 649 cases considered • Only 19% of introductions resulted in transmission lineage of >1 additional case

Source: Jemma Geoghegan et al, MedRxiv. Sept 2020 Components of elimination strategy Resurgence planning & management

Border failures – 8 known 1. August Community cluster – 179 cases (incl. 3 deaths) 2. Auckland MIQ facility maintenance worker Aug) – 1 case 3. Auckland MIQ facility nurse infected (Sept) – 1 case 4. Christchurch MIQ facility cluster (Sept) – 6 cases 5. Auckland Marine employee cluster (Oct) – 3 cases 6. Christchurch MIQ facility nurse #1 (Nov) – 2 cases 7. Christchurch MIQ facility nurse #2 (Nov) – 1 case 8. Auckland MIQ armed forces cluster (Nov) – 5 cases (incl. Case D + E) Components of elimination strategy Resurgence planning & management

Rapid response: • High levels of testing, contact tracing, isolation/quarantine • Alert level increased during in Auckland Aug Cluster • Mass masking on public transport & aircraft Impact of Elimination Strategy Death rate from COVID-19, OECD countries

COVID-19 cumulative death rate (per million) 1600

1400 1339 Source: Wilson et al, PHE Blog, 4 Dec 2020 1200

1000

800

600 406 400 269 200 5 10 0 NZ (lowest in OECD) South Korea (2nd Island nations* OECD average Belgium (highest in lowest) (excluding NZ) (excluding NZ) OECD) Impact of elimination strategy Infection Fatality Risk

Donald trump – Risk factors • Age = 74 years • BMI = 30 • Income = low ($750 federal income tax in 2016) • Homeless (impending eviction) Impact of elimination strategy Equity and Community Partnership • Equity is a major goal of pandemic response, particularly for Māori and Pacific Peoples • Testing, health care access • Disease rates and outcomes • Partnerships with Māori critical • Kōkiri Marae in Wellington • Focus on effects of lockdown: • Food insecurity • Unmet healthcare need, eg long- term conditions, non-COVID infectious diseases Impact of Elimination Strategy Age and ethnicity of COVID-19 cases

• Because of elimination strategy, COVID-19 demographics shaped by incoming travellers: • Majority European ethnicity and 20-29 years • No ‘mature’ outbreak • Auckland August outbreak pointer to uncontrolled spread: • Majority Māori/Pasifika • 34% children

Data source: Ministry of Health COVID-19 line list data Impact of elimination strategy Psychological distress, mental health Lockdown effects: • 30% reported moderate to severe psychological distress • 16% moderate to high levels of anxiety • 39% low wellbeing; well above baseline measures • Suicidal thoughts 6%, with 2% reporting suicide attempts • Rates of suicide reduced (common in acute phase of a crisis) • 10% directly experienced some form of family harm • 64% reporting ‘silver linings’, eg enjoying working from home, spending more time with family, and a quieter, less polluted environment.

Source: Susanna Every-Palmer, University of Otago, Oct 2020. Online panel survey of demographically representative sample n = 2010 in April 2020. Contained 3 standardised measures – the Kessler Psychological Distress Scale (K10), the GAD-7, and the Well-Being Index (WHO-5) – and questions to measure family violence, suicidal ideation, alcohol consumption and positive aspects of the lockdown. Impact of Elimination Strategy Near elimination of seasonal influenza

Source: Huang, et al MedRxiv. Nov 2020 Impact of Elimination Strategy Reduced all-cause mortality & EWM

Source: Telfar Barnard et al. Submitted Oct 2020 Economic impacts Filled jobs (to 20 Sept)

Source: Stats NZ economic data: https://www.stats.govt.nz/experimental/covid-19-data-portal Impact of elimination strategy

Plan Pandemic Strategy Implement Pandemic Strategy Exit path

1. Exclusion strategy: Maximum action to exclude disease Eg. Pacific Island countries and territories Return to carefully managed ‘new normal’ (3 months in Asian Pandemic 2. Elimination strategy: Maximum action to exclude disease countries). Requires persisting planning: Assess and eliminate chains of transmission. Eg. Mainland China, quarantine at borders until threat, choose Taiwan, New Zealand vaccine and/or antivirals available strategy, select interventions* implement 3. Suppression strategy: Action increased in stepwise and Prolonged control measures until ongoing targeted manner to suppress case numbers and outbreaks. vaccine and/or antivirals surveillance and Eg. Most countries in Europe, North America evaluation, fine- available: (12-18+ months) or tune mix of switch strategies interventions 4. Mitigation strategy: Action taken to ‘flatten the peak’ and protect the most vulnerable. Pandemic wave continues, but lower peak. Eg. Sweden at least initially Pandemic spreads through population until immunity and/or vaccine and/or antivirals 5. No substantive strategy: Largely uncontrolled pandemic available: (12-18+months) wave. Eg. Most low-income states

*Control interventions: (1) Border controls to ‘keep it out’; (2) Case isolation & contact quarantine to ‘stamp it out’; (3) Improved hygiene and use of masks; (4) Physical distancing; (5) Movement restrictions; (6) Combinations including ‘lock-down’ NB. There are multiple other interventions to mitigate harm, focussed on health services & protecting vulnerable Impact of Elimination Strategy

Country/ Popul- Peak Cumulative GDP change jurisdic- ation strin- Cumulative Case rate (per Cumulative mortality rate in 2020 (%), Region tion (millions) gency COVID-19 cases million) deaths (per million) (IMF Project) European (n=14) and North American (n=2) countries with population > 10 million Europe UK 68.0 79.6 1,574,562 23,145 57,031 838 -9.8

North Am USA 331.8 72.7 13,228,456 39,870 269,367 812 -4.3 Mean 54.1 80.7 1,609,474 26,718 36,622 618 -7.5 Median 37.9 82.9 621,078 24,933 13,666 606 -7.2 The four East Asian and Australasian jurisdictions using an elimination strategy (articulated or otherwise) East Asia China 1439.3 81.9 86,490 60 4,634 3 1.9 East Asia Taiwan 23.8 30.6 625 26 7 0.3 0.0 Australasia Australia 25.6 79.2 27,867 1,088 907 35 -4.2 Australasia NZ 5.0 96.3 2,040 408 25 5 -6.1 Mean 373.4 72.0 29,256 396 1,393 11 -2.1 Median 24.7 80.6 14,954 234 466 4.0 -2.1 Areas of uncertainty

Global spread • Still in first pandemic wave • Resurgences caused by actions of Governments • Plan for pandemic threat continuing for further 1+ years • SARS-CoV-2 likely to become endemic (like other coronaviruses)

Source: Daily COVID- 19 Cases and Deaths, COVID-19 Dashboard Johns Hopkins University Areas of uncertainty Animal reservoirs • SARS-CoV-2 is a newly emerged zoonotic virus, probably with a bat reservoir • Multiple (>60) reverse zoonotic hosts, eg primates, minks, foxes • Animal reservoirs: • Threat to elimination by sustaining infection & re-infecting humans • Can generate and select genetic mutations which may differ in infectiousness, seriousness, vaccine susceptibility

Minks • SARS-CoV-2 infected multiple mink farms • Re-infected >200 people • Culls in Denmark & other countries Areas of uncertainty Vaccines and immunity • >170 vaccines in clinical trials, 11 at phase 3 • Vaccines appear safe & effective, eg • Pfizer/BioNTech vaccine ≈ 95% effective • Moderna vaccine ≈ 94% effective • Oxford/AstraZeneca ≈ 70%(+) effective • Uncertainties: Duration of immunity, Effectiveness in older people, Role in interrupting transmission

Therapeutics and Antivirals • Multiple drugs likely to improve outcomes, eg dexamethasone Areas of uncertainty

Managing our borders - Move from ‘one size fits all’ to risk-based approach eg ‘traffic lights’ • Green zone – Elimination jurisdictions eg Australia, Pacific Is • Quarantine-free travel with precautions • Amber zone – Well controlled eg Japan, South Korea • Current border quarantine and testing • Red zone – Poorly controlled eg UK, Europe, North America • Additional risk reduction measures (eg additional quarantine period + testing) or suspension of travel

Source: Wilson & Baker, The Conversation 4 Nov 2020 Alternative views Debates, Myths, Misinformation

Jami-Lee Ross (+ Billy Te Kahika NZ Public Party) Alternative views Debates, Myths, Misinformation

Myth Reality 1. COVID-19 is no worse than the flu 1. COVID fatality risk 17x higher than seasonal 2. Learn to live with the virus by just flu* protecting the vulnerable 2. High proportion of pop are >60 years & have 3. Natural herd immunity will protect long term conditions ie hard to protect us 3. Herd immunity requires an effective vaccine 4. We have to choose health of 4. Public health & economic health go together people or health of economy 5. We can open quarantine-free travel to other 5. We can’t seal ourselves off forever virus-free countries 6. Sweden did it better 6. Taiwan did it better

*Source: Baker & Wilson, BMJ 2020 Oct 6;371. Alternative views International comparisons NZ Taiwan • 5 million people • 24 million people • 1,943 Cases = 388 / million • 550 Cases = 23 / million • 25 Deaths = 5 / million • 7 Deaths = 0.3 / million • Stringent lockdown • No lockdown • Elimination with outbreaks • Sustained elimination

• No dedicated public health agency • Dedicated public health agency • Mask use not established • Mask use widely established & promoted • No digital contact tracing • Digital contact tracing • Late border management • Early border management

Source: Summers et al. Lancet Regional Health-Western Pacific. 2020 Oct 21:100044 Key lessons from COVID-19 elimination in NZ

Effective Science + Good Political Leadership Key lessons from COVID-19 elimination in NZ

Improved public health infrastructure & decision-making frameworks eg, that can manage diverse range of pandemic threats

Source: Kvalsvig & Baker, Under review, Oct 2020 Key lessons from COVID-19 elimination in NZ Application of elimination approach to other IDs: Eradicated diseases • Smallpox, Rinderpest Global eradication underway • Poliomyelitis (polio), Dracunculiasis, Yaws Pandemic diseases where elimination is possible • Emerging ID (eg COVID-19), Pandemic influenza Regional elimination established or underway • Measles, Rubella • Hookworm, Lymphatic filariasis, Onchocerciasis, African trypanosomiasis, Malaria, Rabies, • Syphilis, nvCJD (from BSE) Other diseases where elimination proposed • HIV, Hepatitis B, Hepatitis C, TB • HPV (cervical cancer), H. pylori (stomach cancer) Key lessons from COVID-19 elimination in NZ

• Opportunity for broad reset and increased focus on managing major global health threats • Most NZers want a green recovery* • More equitable society also assists with collective action against future threats

*Source: Massey Uni Survey, August 2020. 7/10 NZers want a green recovery. https://www.newstalkzb.co.nz/news/business/seven- in-10-kiwis-want-a-green-covid-19-recovery-survey/ Summary

• Importance of Effective Science + Good Political Leadership, with high-quality risk assessment & rapid, decisive response • NZ choice of elimination appears to protect health & economy more than alternative strategies • Opportunity to strengthen public health Can we learn the lessons capacity of history? • Opportunity for major reset towards a more equitable & sustainable society Acknowledgements

COVID-19 Research Collaborative • Based at the University of Otago, multiple collaborations • Director: Michael Baker, Lead Researchers: Amanda Kvalsvig, Nick Wilson • Goal: To support an effective and equitable pandemic response • Researchers from Universities (x3), CRI, Community group • Funding from HRC, philanthropic organisations, Universities

Photo credits: Luke Pilkinton-Ching Contact Michael Baker [email protected] Amanda Kvalsvig [email protected]