Teaching Heroes with Dr Joanna Winchester

It was such a delight to chat with Dr Joanna Winchester for her Teaching Heroes podcast.

We had a pretty wide-ranging discussion about health equity, how the COVID response could be exacerbating health inequities, vaccination for teachers, and how the return to classrooms might play out – including the role that HEPA filters might play.

We also briefly spoke about the early 20th-century movement for open-air schooling, and how some of these design ideas may make a comeback

Thanks Jo!

Now it gets more difficult

From the University of Melbourne’s Vaccine Hesitancy Tracker:

Vaccine hesitancy across Australia has fallen from 21.8% on 7th August to 20.3% on 20th August

This fall is concentrated amongst those who were previously unsure, with 8.6% unsure on 20th August compared to 9.8% two weeks earlier. The percentage unwilling to be vaccinated has not changed much in the past month

Vaccine hesitancy in NSW is still the lowest in Australia. However, hesitancy has increased slightly in NSW despite the continuing rise in cases of COVID-19, from 17.3% on 7th August to 18% on 20th August

In NSW over the last two weeks, more people are unwilling to be vaccinated (from 9.2% to 11.8%) and fewer are unsure (from 8.1% to 6.2%). Those who are unsure are more likely to be influenced by incentives. More information can be found in this Research Insight article

Source: Vaccine Hesitancy Tracker

As schools open up, could HEPA air filters play a role in making them safer?

Associate Professor Donna Green and I had a chance to speak with Cassie McCullagh on ABC Radio Sydney’s Focus about high-efficiency particulate air (HEPA) filters in schools, based on our earlier piece at The Conversation.

Cassie McCullagh – HEPA filters in schools – 1 September 2021 Download MP3

Interestingly, I noted that a US academic has also written for The Conversation US about HEPA filters in schools, and sums up some of the equity considerations and limitations quite well:

In-room HEPA filtration is a long-term investment that supplements existing ventilation systems. And though COVID-19 was the impetus for the installation of many HEPA filters, they are effective for far more than just reducing exposures to airborne viruses. Well-maintained and properly functioning filtration systems also reduce exposure to wildfire ash that can penetrate buildings, as well as allergens and other unwanted particles like automobile exhaust, tire detritus and construction dust. 

But even the best indoor HEPA filtration cannot guarantee protection from airborne respiratory threats in schools. HEPA filters are effective only as part of an integrated approach. Ultimately, masks, distancing and reducing the number of students packed into tight spaces will determine how well students are protected from COVID-19.

COVID-19 has spurred investments in air filtration for K-12 schools – but these technologies aren’t an instant fix

Who could have seen this?

An interesting post on Social behavior and the covid pandemic, but the last bit of this quote jumped out at me:

But here’s the thing: what 2010-era sociologist or political scientist would have predicted that a major global pandemic would occur in the next several decades, that an almost miraculous search for an effective vaccine would be successful in an amazingly short period — and that the pandemic and vaccine would become a political issue leading to mass refusal to vaccinate? All global epidemiologists believed the first proposition — that pandemic would occur sometime; some biological researchers thought that vaccine creation could advance quickly; but I can’t think of any respected political scientist or sociologist who would have predicted the massive movement that has emerged against vaccination and the politicization of the spread of the virus. 

Social behavior and the covid pandemic – Understanding Society

I can’t think of many social scientists working in vaccination who haven’t been thinking about this for at least a decade.

Twelve sounds better than 2.3 million

In the discussion about the twelve NSW local government “areas of concern” that are under tighter restrictions, I’ve noticed that the number of people affected is never mentioned. So I looked it up and there are more than 2.3 million people living in the twelve LGAs (table below).

About 1 in 10 people in Australia live in a NSW Local Government Areas of Concern, which means they’re under curfew and need permits to leave their LGAs

Local Government2019 population estimate
Bayside 170,089
Blacktown 357,479
Burwood 39,310
Campbelltown 164,508
Canterbury-Bankstown 368,045
Cumberland 231,443
Fairfield 208,468
Georges River 156,293
Liverpool 217,586
Parramatta 243,276
Strathfield 43,803
Penrith suburbs of Caddens, Claremont Meadows, Colyton, Erskine Park, Kemps Creek, Kingswood, Mount Vernon, North St Marys, Orchard Hills, Oxley Park, St Clair, St Marys~100,000
TOTAL 2,300,300

Chasing vaccine records

I was quoted in yesterday’s Herald in a piece about people whose COVID vaccination records have gone missing. I’ve been whingeing about this to anyone who’ll listen for the past few months. For a while, it seemed like the easiest thing would be to get another vacination. It’s good to hear that I’m not alone.

The issue seems to have been that the Immunisation Register doesn’t like hyphens or apostrophes in people’s names (seriously). Even if this only affects one percent of people, that’s 60,000 in NSW alone.

Anyway, the story was tweeted by Bill Shorten, which is a pretty good sign I’ve made a mistake by complaining about it.

I’ve made a terrible mistake.

When an evidence-based approach entrenches inequalities

The curfew and further COVID control measures that were announced today have had me thinking about how a narrow approach to what constitutes evidence can exacerbate health inequalities.

As Prof Catherine Bennett points out, reducing the reproduction rate of the Delta variant to 1.2-1.3 has itself been a major achievement.

However, because COVID spreads based on inequalities – insecure work, where people live, housing conditions, inability to isolate – a targeted approach based on epidemiological data alone can lead to interventions that reinforce inequities. Interventions like curfews, limiting people to one hour outside the home, and increased policing are unlikely to have an influence on COVID transmission. If anything, they’re only likely to lead to increased criminal justice engagement and charges. They’re also not based on public health evidence.

Because these measures are only being imposed in the poorer parts of Sydney where COVID is circulating most, they’re entrenching determinants of health inequity.

Eighteen months ago, when I was still trying to figure what COVID was all about, I wrote:

There is likely to be a social gradient in transmission, i.e. the poor are more likely to get COVID-19, at least at first. This is a concern that some have already flagged in the U.S.

If there is a social gradient in the disease, there needs to be a social gradient in our response. The most affected locations and communities should be the focus of the health system’s initial response (we can’t just assume this will be the case). If antiviral therapies are found to be effective, or if a vaccine is eventually developed, consideration should be given to deploying them to poorer areas first.

“The first wave hits the poor, the second wave hits the rich”: Lessons from the 1918 pandemic

Now is the time for that social gradient in the response to finally start.

To change the pandemic control, listen to the communities in western and south western Sydney

Thanks to Cate Carrigan and Croakey for the chance to chat about COVID and compliance theatre in Western Sydney – and what might make a difference.

“The thing that gives me hope is that if you look at the numbers, they really peaked in Fairfield a month ago and have come down. This is because of the huge efforts by community groups there,” says Harris-Roxas.

The Assyrian, Lebanese, Sudanese and Syrian communities are providing material assistance and information to their networks, using Zoom and social media, he says.

The value of these community ties has been evident in the strong response to the vaccine clinic set up by the Lebanese Muslim Association at Lakemba in south west Sydney.

Read more at To improve pandemic control, listen to the community leaders of western and south west Sydney

We should install air purifiers with HEPA filters in every classroom. It could help with COVID, bushfire smoke and asthma

Saying “open a window to reduce COVID risks” makes sense unless there’s bushfire smoke and poor air quality. 

As NSW ponders how schools can reopen safely after the current COVID lockdown, A/Prof Donna Green and I estimate that a $50 million investment can reduce not only COVID risks but also bushfire smoke and asthma risks as well – and needs to be tackled urgently.

This post first appeared at The Conversation.


The smell of hazard reduction burn smoke in Sydney this week is an unwelcome reminder the bushfire season is almost upon us, and with it, the torment of having to breathe toxic air

Even before the last of the 2019–20 Black Summer smoke dissipated, another deadly reminder of the importance of access to safe air arrived. COVID forced many of us to take a crash course in how to avoid respiratory viruses.

One of the most effective ways to reduce indoor COVID transmission is to open windows. Maximising outdoor air coming inside, known as the air exchange rate, is a good way to reduce transmission risk.

But opening windows during the bushfire season can let toxic smoke in, changing the risk calculation.

Keeping windows closed and re-circulating air through standard aircon systems can cool the air, but doesn’t remove smoke or viruses.

So how can schools reduce exposure to COVID and bushfire smoke simultaneously?

This dilemma has a solution we can implement immediately. We’ve calculated about A$50 million would provide all NSW primary and secondary school classrooms, and other shared spaces within schools, with High-Efficiency Particulate Air (HEPA) grade air purifiers.

This initial outlay pales compared to the roughly A$220 million-a-day cost of Sydney’s lockdown. 

The added benefit of installing air purifiers with HEPA filters is they can help reduce the risk of asthma attacks too.

Air purifiers with HEPA filters can remove over 99% of tiny particles

Most people catch COVID by inhaling it from shared air, and COVID particles often linger in the air in indoor spaces. Simple and relatively cheap air purifiers with HEPA filters have been shown to clear potentially infectious aerosols quickly and effectively

HEPA air purifiers work by mechanical filtration — they force air through a fine mesh which traps particles. Off-the-shelf air purifers with HEPA filters can remove more than 99.97% of all particle sizes down to 0.30-1.0 microns (one millionth of a metre).

This means they can help filter airborne viruses, bacteria, and tiny particles known as “particulate matter” from bushfire or hazard reduction burn smoke. They can’t completely eliminate COVID transmission, but they can help reduce the risk especially when used with other best practices like wearing masks and other public health measures.

This approach isn’t radical. It has already been mandated in New York schools prior to their reopening.

Our calculations

These calculations assume each NSW primary and secondary school student, of which there are approximately 706,000 and 534,000, respectively, are grouped in classes of 25 and 20 pupils, respectively.

Each of these classrooms would require an air purifier designed to work in a standard classroom of approximately 60 square metres. We’ve allowed for each of the 3,100 schools in NSW to have six extra units to include shared spaces such as the library or resource room, staff room and administration area.

Approximately 73,500 units would be needed in NSW. We’ve applied a bulk buy discount of 30% on a currently available, high-quality HEPA air purifier retailing for A$1,000 to arrive at our estimate.

Of course, this doesn’t only affect NSW — schools across the nation would likely benefit from this approach.

Because these units are already available for purchase online and can ship via existing delivery services, the logistics are neither complicated nor expensive. 

Installation of the units can be carried out in minutes, and one of the only concerns is the need to ensure proper PPE when changing the filter. 

Unfortunately, upgrading existing aircon systems in schools by incorporating higher-grade HEPA filters is slow, expensive and not always technically possible. 

In combination with other risk-reduction strategies, air purifiers could be an affordable way to reduce the risk of unmitigated COVID spread between unvaccinated students and staff, and the inevitable spread between, and within, these children’s households.

This approach would buy time until vaccines are approved and rolled out for Australian children. This is unlikely to occur before mid-2022 at the earliest. 

There are multiple other benefits too

An added benefit is that for future years, these air purifiers might be able to reduce asthma attacks triggered by smoke from the inevitable, and increasingly intense, bushfire season. That’s because for many people, asthma can be triggered by the small particles in smoke which, once inhaled, can go into the lungs causing inflammation.

Their tiny size means some of them can enter the blood stream and affect our lungsheart and immune systems.

One in ten Australian children suffer from asthma, so keeping hazard reduction burn and bushfire smoke out of schools is a top priority.

Using HEPA filters will likely result in health savings associated with reduced asthma attacks from avoided smoke inhalation, and a lower burden from COVID cases stemming from school-based transmission. This will place less pressure on NSW’s overwhelmed health system.

It’s hard to comprehend why we haven’t raced to take such an effective no-regrets strategy.

It’s one strategy of many

Installing air purifiers with HEPA filters throughout the entire school system might be one of the most important, and cost effective, ways to improve the health and safety for millions of families in NSW, and around Australia.

We also need to deploy a range of strategies to reduce the risk to school children and staff of exposure to airborne viruses, as well as smoke and other air pollutants.

We know we also need to:

  • promote outdoor sports over indoors
  • stagger outside playground access times
  • move non-essential person-to-person interactions online (for example parent-teacher meetings)
  • perform rigorous daily checks for symptomatic children
  • constantly encourage people with even the most minor symptoms to stay home and get tested
  • mandate masks in schools and on public transport
  • stagger drop off and pick up times where possible.

More than 50 long-term effects of COVID-19: a systematic review and meta-analysis

More evidence and research from multi-disciplinary teams are crucial to understanding the causes, mechanisms, and risks to develop preventive measures, rehabilitation techniques, and clinical management strategies with whole-patient perspectives designed to address the after-COVID-19 care. There is a need for more information about prospective studies to better evaluate the natural course of COVID-19 infection and define the long- COVID-19 syndrome. From the clinical point of view, physicians should be aware of the symptoms, signs, and biomarkers present in patients previously affected by COVID-19 to promptly assess, identify and halt long COVID-19 progression, minimize the risk of chronic effects help reestablish pre-COVID-19 health. Management of all these effects requires further understanding to design individualized, dynamic cross-sectoral interventions in Post-COVID-19 clinics with multiple specialties, including graded exercise, physical therapy, frequent medical evaluations, and cognitive behavioral therapy when required
— Read on www.nature.com/articles/s41598-021-95565-8