Masks only useful in confined spaces

Media Release

14 August 2020

Epidemiologist Simon Thornley has reassured people that there has been no new information that concludes masks are warranted against COVID19.

“The trials are clear; there is no statistically useful safety gain in wearing a mask, although low quality observational studies show an advantage to wearing one in confined spaces.”

Thornley says he was moved to clarify the science because people advocating masks were claiming ‘things had changed’, leading to an increase in public mask-wearing since Wednesday.

“Nothing in medical science has changed since Ashley Bloomfield first told us months ago that there was no advantage to masks. What has changed is social and political advantage in advocating masks, and that’s not science.

“I will not be wearing a mask without symptoms, but anyone with compromised health could choose to carry a mask to wear in places like public transport.”

Thornley urged all public communicators, including media, to reference the latest science on masks so people could decide for themselves (see below).

On Monday, the Covid Plan B group is live streaming a COVID-19 Science and Policy Symposium, featuring international experts analysing the New Zealand situation. Find out more here.

ENDS

The Science on masks

A trial in Australia showed that in households exposed to children with respiratory symptoms and fever, there was no difference in outcome between households that wore either surgical or P2 masks with controls who did not wear masks. The incidence of laboratory confirmed infections were twice as high in the mask wearing groups compared to controls, but the difference was not statistically significant.1 About 50% of patients reported problems with the masks, and by day five, only 30% of participants were compliant with the mask use.

A larger trial in Thailand that compared control, to handwashing, and handwashing and surgical masks in households with influenza-like illness showed no difference between the three groups, in terms of reducing the incidence of secondary transmission from primary cases.2

Meta-analyses of observational studies have reported benefits of reductions in risk of using masks.3 A case-control study of H1N1 transmission following a prolonged flight between China and the US showed a very strong association between mask use and protection from infection. None of the 9 cases wore masks, compared to 47% (15/32) of control passengers.4

The World Health Organisation5 only recommends masks when individuals have symptoms compatible with Covid-19. In populations such as those with a high prevalence of Covid, immunocompromised patients or times where high population density cannot be avoided, such as mass gatherings, public transportation (including aeroplanes), masks are considered useful for ‘source control’, rather than ‘protection’.

References

  1. MacIntyre CR, Cauchemez S, Dwyer DE, et al. Face mask use and control of respiratory virus transmission in households. Emerging infectious diseases 2009;15(2):233.
  2. Simmerman JM, Suntarattiwong P, Levy J, et al. Findings from a household randomized controlled trial of hand washing and face masks to reduce influenza transmission in Bangkok, Thailand. Influenza and other respiratory viruses 2011;5(4):256-67.
  3. Chu DK, Akl EA, Duda S, et al. Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis. The Lancet 2020;395(10242):1973-87. doi: https://doi.org/10.1016/S0140-6736(20)31142-9
  4. Zhang L, Peng Z, Ou J, et al. Protection by face masks against influenza A(H1N1)pdm09 virus on trans-Pacific passenger aircraft, 2009. Emerging infectious diseases 2013;19(9):1403-10. doi: 10.3201/eid1909.121765
  5. Organization WH. Advice on the use of masks in the context of COVID-19: interim guidance, 5 June 2020: World Health Organization, 2020.

New lockdowns are proof that they don’t work

Media Release

13 August 2020

Epidemiologist Simon Thornley says the new virus outbreaks and lockdown responses are proof that New Zealand must, as the WHO has recently said, learn to live with the virus.

“An outbreak was inevitable, and therefore lockdowns were never a viable repeatable solution – you pay a high price, repeatedly.”

“As we’re about to experience yet again, lockdowns harm everyone more than the coronavirus does.”

“Protecting the elderly, staying at home if you are ill and hand hygiene are the mainstays of reducing the spread of the virus.”

Thornley says it is ironic that the Government had now also decided to lock down all aged care facilities.

“This is precisely the solution we advocated three months ago. Proof has since mounted that those of us over 65 are the only people at real risk: the age of death with this virus is much the same as what we observed in people who died last year. The risk is extremely low for people aged less than 65. No one has yet died in their fifties or younger in New Zealand.

Even in apparently ‘hard hit’ regions of the world, people aged less than 65 without underlying conditions were very unlikely to die from the virus. They accounted for 0.7–3.6% of all COVID deaths in France, Italy, Netherlands, Sweden, Georgia, and New York City.

“Safe hygiene practices and protection of the elderly is the best solution.” Thornley said.

Thornley points out that the Government promised that the first lockdown was to eliminate the virus, and its four-day extension would ‘lock in the gains’.

“Yet here we are, with the virus, locking down again. Proof, if you needed it, that lockdowns only delay, or even magnify, the health and economic harm.”

On Monday 17 August, the Covid Plan B group is live streaming the COVID-19 Science and Policy Symposium, featuring international experts analysing the New Zealand situation.

The international speakers confirmed include founder of Yale University’s Yale-Griffin Prevention Research Centre Dr David Katz, who worked at the front line of New York hospitals dealing with patients, and viral immunologist Dr Byram Bridle who is part of a team commissioned by the Canadian Government to develop a COVID vaccine.

To find out more information about the COVID-19 Science and Policy Symposium, visit here.

ENDS

WHO highlights NZ border problem – International symposium to tackle dilemma

 

Media Release

28 July 2020

Several World Health Organisation officials have this week crystallised New Zealand’s border dilemma – saying that keeping national borders closed because of COVID-19 is now unfeasible.

Head of WHO’s emergencies program lead Mike Ryan said “it is going to be almost impossible for individual countries to keep their borders shut for the foreseeable future…. Economies have to open up, people have to work, trade has to resume.”

Simon Thornley, of the Covid Plan B Group, says this highlights a core problem the group had with lockdown; there was no exit strategy.

“New Zealand came out of lockdown well, but the suppression strategy has left us in an international and economic dead end.

“Other nations, although worse hit by cases and deaths, are now opening up borders and activity. New Zealand is in a bind; locked behind its border, fearful of even a single infection let alone a death.

“Yet the most recent infection fatality studies show Covid-19 is 0.65% – at most only a quarter of the deaths we expected, and probably far fewer.

“We need to open our borders to restore economic and social connections with the rest of the world.”

Thornley said New Zealand’s dilemma would be tackled by an international symposium at Parliament on 17 August, featuring several internationally respected experts. They will analyse the latest information on COVID-19 to offer possible pathways for New Zealand’s recovery.

“The main danger of the virus is that hospitals become overwhelmed and the virus spreads to frail patients. Most countries are now well beyond this, but New Zealand might not be. We need to cautiously open our borders and continue to monitor our health system’s capacity.”

The international speakers will present live by video link, followed by questions from the public. They include vaccine specialist Byram Bridle, Epidemiology Professor Sunetra Gupta of Oxford University, and Preventative Medicine specialist David Katz at Yale.

Interested parties can register for free tickets here. To find out more information about presenters at this event, please visit here.

ENDS

Oxford professor criticises NZ suppression strategy

Media Release

21 July 2020

An Oxford professor has criticised New Zealand’s Covid-19 strategy ahead of an international symposium on New Zealand’s policy options to be held in Parliament in August.

Professor Carl Heneghan from the Oxford Centre for Evidence Based Medicine said in an interview on the weekend that “If you follow the New Zealand policy of suppressing it to zero and locking down the country forever, then you’re going to have a problem… This virus is so out there now, I cannot see a strategy that makes suppression the viable option. The strategy right now should be how we learn to live with this virus”

Simon Thornley, of the Covid Plan B Group, has today announced plans to hold an international symposium on New Zealand’s policy options at Parliament on 17 August.

The COVID-19 Science and Policy Symposium will feature at least five internationally respected academics and scientists analysing the latest information of COVID-19 to offer possible pathways for New Zealand’s recovery, along with New Zealand-based experts.

Thornley says experts were keen to present at the symposium because New Zealand is receiving global attention for its handling of the pandemic and the situation it is now in.

“New Zealand’s approach is a hot topic internationally – experts are keen to discuss our unique position. Our low infection and death rate has created a difficult decision on when and how we open back up to the world.

“The risks and impacts of the virus are now becoming much clearer and more certain. This information is vital to New Zealand’s decision-making, but we’re not getting the full picture.”

The international speakers will join by video link, giving presentations on the latest data, and open to discussion and questions from the public.

Those confirmed include Dr David Katz, founder of the Yale-Griffin Prevention Research Centre and who worked at the front line of New York hospitals dealing with patients, and viral immunologist Dr Byram Bridle who is part of a team commissioned by the Canadian Government to develop a vaccine.

The COVID-19 Science and Policy Symposium will be held in Parliament’s Banquet Hall on Monday 17 August. Interested parties can register for free tickets here.

To find out more information about presenters at this event, please visit here.

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NZ Govt confirms it won’t test for virus prevalence

Media Statement

8 July 2020

The Government has formally confirmed that it will not use any of the current or future serology tests to assess how widespread the Covid19 disease has been in New Zealand.

In answer to an Official Information Request by the Covid Plan B group, the Director of the COVID-19 Health System Response team in the Ministry of Health said serology tests would underestimate the true level of exposure to Covid-19.

Epidemiologist Simon Thornley says the new policy is the opposite of what was done in 2009 when serology data on low prevalence of swine flu convinced health officials not to take extreme control measures.

“Serology testing will underestimate the true prevalence, but that will be many times more accurate than just guessing from tests of people presenting with symptoms.

“Fear and uncertainty are driven by lack of information. The more we know, the better we can fight disease. It has been the policy in the past, so it’s strange not to do it now.”

Thornley says a consistent picture is emerging that nose tests for Covid-19 are only picking up a small fraction of all cases.

“Antibodies, present in the blood as well as T cell immune responses to the virus are revealing the coronavirus has reached far more people than listed in the daily “cases” statistic.

“That is important because it would reveal the true effectiveness of our protective measures, and the true state of our population immunity to coronavirus.”

In response to the OIA request for data from serology testing, the Government confirmed:

“Currently there are no Ministry sanctioned seroprevalence studies being performed”.

It claimed that this was supported by a letter in the Nature Medicine journal which indicated that one study found variability in individuals; 40% of asymptomatic people became seronegative and 13% of symptomatic people became negative for IgG [An immunoglobulin] as they recovered.

It noted that a study had been undertaken by the Southern DHB, and that “Positive COVID-19 cases from the Southern DHB study will be confirmed on a second assay to increase positive prediction value.” It said “future studies will have to learn from the Southern DHB study and adapt its methodology accordingly.” The Ministry added that there had been blood mononuclear cell collection by the University of Otago which would be used to perform future mediated response testing.

/ends

Contact Simon Thornley 021 299 1752

Erroneous Covid modellers reveal myopic focus

5 June 2020

Media Release

The Covid-19 Plan B group has dismissed as “scaremongering” a claim that an 8% chance of a Covid-19 outbreak under Level 1 means New Zealand should continue in level 2, and restrict large gatherings, based on the risk of spread they pose.

Epidemiologist and Covid-19 Plan B spokesperson Simon Thornley says; “The team that incorrectly forecast 80,000 Covid-19 deaths in New Zealand are back, now claiming that moving down to Level 1 will increase the risk of a large outbreak from 3 to 8 per cent.

“The Plan B group want to underscore that the chance of large outbreaks is low, since the latest evidence, from both immunology studies overseas, and epicurves in many countries strongly suggests that population immunity is high.

“Countries such as China, Taiwan, Switzerland, Slovenia and ourselves that have now recovered from the epidemic have experienced low levels of new cases for several weeks. Slovenia has even opened its borders to travelers from other European Union nations, without the requirement for quarantine.

This is also supported by recent data from Japan, which went lower than New Zealand’s level 2 over 12 days ago. The much more densely populated country than New Zealand has not seen spikes in cases.

Evidence is becoming clearer that enforcing harsh social distancing measures have little to no effect. The Matatini group seem to have ignored these studies, and simply assumed that distancing works.”

Thornley points out that the 8% risk is small compared to all the costs of lockdown that are now apparent, such as deferred health treatment, unemployment, business collapses and public debt.

“The priority now should be to flatten the severe economic recession that is imminent, and return the majority of our country to normal life, while doing our best to protect the vulnerable.”

/ends

Contact: Simon Thornley, mob: 0212991752

Thornley: we should be at Level 1 by now

Cabinet is set to look at whether New Zealand should move to level 1 on June 22, but pressure is mounting to move earlier, with Deputy Prime Minister Winston Peters saying it should have already happened.

Dr Simon Thornley, senior lecturer of public health at Auckland University, told Mike Hosking we should be at level 1 by now.

“A second wave is extremely unlikely.

“Japan have opened up and they haven’t had a second wave and they have a of things against them that we don’t have, like densely populated cities.”

Thornley also says a travel bubble between New Zealand and Australia is now safe.

https://www.newstalkzb.co.nz/on-air/mike-hosking-breakfast/audio/dr-simon-thornley-we-should-be-at-level-1-by-now/

Are the coronavirus epidemiological models any good?

Health issues India discuss coronavirus models with Dr Simon Thornley.

 

How to respond to a spike in COVID-19

Media Statement

17 May 2020

Epidemiologist Simon Thornley says is likely that there will be a rise in COVID-19 cases in New Zealand, so while there is no need to return to national lockdown, protection of vulnerable people is necessary.

“Internationally lockdowns have not prevented subsequent spikes in the number of cases, such as in Hokkaido, Japan. Lockdowns just slow or delay the inevitable resurgence of COVID-19.

“While the evidence does not endorse further lockdowns, even in the face of further cases, the elderly deserve protection. The rest of us can safely get on with our lives.

“I expect COVID-19 to join other coronaviruses such as HCoV-229E, HCoV-HKU1 and HCoV-OC43 as endemic with winter seasonal peaks – when they cause fatalities in rest homes. So, we need to take particular care toward older people and those with co-morbidities.

Thornley says that to justify a renewed lockdown the Government would need to argue health services were at risk, public immunity was low, and the risk to people’s health was major.

“The nation may lack immunity due to lockdown – but we have no information because the Government hasn’t done serology tests. But we do appear to have enough health service capacity, and for most of us the virus poses very little danger.”

There is now compelling evidence that lockdowns in Europe were not especially effective, and that there was no difference in per capital cases and deaths in a comparison of US States. The main factor linked to cases and deaths has been found to be testing rates; the more tests that were carried out by State, the more cases were found.

The risk of future waves is related to our exposure to the virus. Tests of immunity in hard hit countries are returning immunity levels of about 5%, such as in Spain. Other tests of cell mediated immunity suggest higher real levels of immunity than those obtained from antibody tests alone. In Germany, 34% of antibody negative healthy donors showed markers of cellular immunity. The rise, fall and now low number of cases in China, with smaller contained outbreaks after the initial peak, suggest that immunity is sustained, at least in the medium term.

In even hard hit countries the risk of death from the virus for the majority of working age people, especially those under the age of forty, the mortality risk is very low.

Contact: Simon Thornley, 021 299 1752

RETURN TO SCHOOL GIVEN OKAY

26 April 2020

MEDIA RELEASE

Simon Thornley, epidemiologist with the Covid Plan B Group, says parents who need to send their children to school this week should not be fearful, as the chance of exposure to Covid-19 is very low and their chance of being harmed if they catch it is extremely small.

Thornley says in a post to the Plan B website that the risk is not the same for everyone.

“Your risk of dying from the virus is about the same as your risk of dying that year given your age.

“This means that children of school age are extremely low risk for having severe complications from the virus.

“It is very sensible for the government to open schools. I believe that this will help build higher levels of immunity in children to act as barriers for the spread to elderly and those with pre-existing medical conditions. These people are the ones we really want to protect from the virus.

“Modellers have concluded that school closures are unlikely to be an effective strategy for halting Covid-19.”

In a systematic review of scientific studies relating to Covid-19 in children, the authors concluded that children had a much milder response to the virus than for adults. Of three children that required intensive care, all had severe underlying conditions.

In one case-series in China, 90% of test-positive cases had no symptoms attributable to the virus. Of all children, infants are more likely to have severe complications.

One possible objection to returning to school is that adults could catch the infection from children.

“While this is possible, an analysis of cases from Shenzhen, China, shows that attack rates are higher in older adults and the majority of transmission occurs among household contacts.

New Zealand has had a Covid-19 cluster of about 92 students at Marist College in Mount Albert, Auckland. The first identified case was a teacher and 12 students have subsequently tested positive. The majority of cases have been adults and at the time of writing, 79 cases had recovered.

In New Zealand, there is little evidence of risk from spread of infection in children. According to the Ministry of Health, there were 18/344 or 5% of New Zealand’s active cases in people  under the age of 20 years. Overseas data shows that immunity to the virus is building in populations that have been tested.

\ends