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news article re herd immunity with a neon traffic sign

November 30, 2020 - Dr. Archer's Update on COVID-19 response from the DOM and Medicine Program


1) Why herd immunity won’t work until a vaccine is widely used (click here)

2) Ontario has had 116,492 cases with 1746 new cases since yesterday and a total of 13,779 active case in Ontario and a 4.3% hospitalization rate (click here): 

3) COVID-19 volumes continue to increase in KFL&A although we remain in YELLOW status (see update from KFL& A Public Health)

4) Canada’s second wave of COVID-19: 371,991 total cases, a rapid spike in infection in western Canada and Nunavut (click here)

5) 5) The COVID-19 global pandemic exceeds 1.46 million deaths and almost 63 million cases, up 2 million since Thursday (click here)

6) The US-Canadian border will remain closed for routine travel at least until the December 21, 2020 while for other countries borders remain closed until Jan 21st 2021 (click here).

Regular reminders and updates:

  • KHSC bed capacity (not updated at time of note) 
  • Use the Mobile Screening Tool to expedite clinic visits 
  • KHSC visitor policy
  • COVID-19 testing at Beechgrove Community Assessment Center: (click here): 
  • Increased outbreaks and deaths in Long Term Care facilities (LTC)
  • COVID-19 in toddlers and young children: (click here). 

1) Why herd immunity won’t work until a vaccine is widely used (click here): The outgoing US President and the signatories of the Great Barrington Declaration, a movement that advocates against many widely accepted public health measures (click here), believe that we should allow people to get infected so that they develop immunity. They reason that this will protect the economy and that once enough people have been infected society will be protected by “herd immunity”. The herd in this case is “we the people”. This is cold calculus and fails to account not only for the death of the vulnerable (who are impossible to protect when the disease is widespread in society); it also fails to account for the morbidity that even young people may suffer from a COVID-19 infection. Finally, the outgoing president and GDB adherents miscalculate the proportion of a population that needs to be immune to confirm herd immunity. They promote numbers in the 10-40% range. So with the pandemic raging for a year where are we with the development of natural immunity (i.e. immunity achieved by surviving an infection)?

It is estimated by testing for antibodies that only 1 in 5 to 1 in 10 infections may actually be diagnosed. Thus with 60 million diagnosed infections globally, it is possible that 5-10X more people have actually been infected. However, even if there have been 600,000,000 COVID-19 infections, that still only 7.7% of the planet’s 7.8 billion people! Herd immunity is a “real thing” but the ability of immune people to block the spread of an infection to the nonimmune people tends to kick in when ~70% of the population is immune. So we would have a long painful road if ongoing infection were chosen as our route to herd immunity. Fortunately, vaccines are a safe and rapid way to both personal and herd immunity(and no one need dies or be damaged). 

I wrote about the flaws in the Great Barrington declaration (GBD) recently (click here). A new article in Nature further discusses the weakness of their logic (click here). In response to my article in the The Conversation some have said that this is just a case of differing opinion between experts, with the GBD having by far the most signatories. For some this raises the question why they should believe one group of experts versus another. Allow me to clarify. The GBD’s website allows anyone to add their name to the list if they provide an email address, home city, postcode and name. In other words, the signatories are not curated/validated and many are simply lay people with an opinion. According to a recent article in The Guardian, GBD’s “….Expert signatories, include “Dr Johnny Bananas” and “Professor Cominic Dummings” (click here)”. Others listed include a resident at the “university of your mum” and another supposed specialist whose name was the first verse of the Macarena.

screenshot of news article with neon sign stating follow the rules have symptoms get a test

The Great Barrington’s declaration’s 160,000 signatory list is not validated; many folks who signed are simply lay people with strong, libertarian views (click here). 

Here is a snippet from the Guardian Article of this topic:

“The chief executive of NHS England, Sir Simon Stevens, has said asking all over-65s to shield to slow the transmission of the second wave of coronavirus would be “age-based apartheid”.

The declaration has also been accused of ignoring the growing evidence on long Covid, whereby thousands of fit and young people who contract the virus have been left with debilitating symptoms months after a mild infection.

The declaration calls for an approach it describes as “focused protection”, arguing that keeping lockdowns in place until a vaccine is available “will cause irreparable damage, with the underprivileged disproportionately harmed”.

In Nature 587, 26-28 (2020), Christie Aschwanden states, “Typically, herd immunity is discussed as a desirable result of wide-scale vaccination programmes. High levels of vaccination-induced immunity in the population benefits those who can’t receive or sufficiently respond to a vaccine, such as people with compromised immune systems. Many medical professionals hate the term herd immunity, and prefer to call it “herd protection”, Buckee says. That’s because the phenomenon doesn’t actually confer immunity to the virus itself — it only reduces the risk that vulnerable people will come into contact with the pathogen.” The article also has some illustrative cases, like the spread of COVID-19 in prisons, where spread did not slow until over 60% of inmates were infected. In addition, Sweden, which took a GBD-like “hands off” approach to public health, has suffered the consequences. Sweden has had >10 times the number of COVID- 19 deaths per 100,000 people s neighboring Norway (58.12 per 100,000, compared with 5.23 per 100,000 in Norway). Sweden’s case fatality rate is also at least three times those of Norway and nearby Denmark.

So why delve into this confusing mess? Because it matters! If we accept that we need good public health measures until vaccinations bring about herd immunity many thousands of deaths and hundreds of thousands of infection will be prevented. So I urge you and your family to be ready to embrace the vaccine when it arrives and until then follow our very reasonable and nuanced local public health policies.

2) Ontario’s has had 116,492 cases with 1746 new cases since yesterday and a total of 13,779 active case in Ontario and a 4.3% hospitalization rate (click here): 

table of Ontarios pandemic at a glance

Ontario’s pandemic at a glance Nov 30th (click here(NB-update slightly earlier than new case data mentioned above, accounting for smaller new case number and total case number)

There were 1,746 new cases today, up +1.5% from yesterday (click here). There have been 7438 hospitalizations, and 3656 deaths in Ontario, since the pandemic began (up 6.5% and 3.2% since yesterday, respectively). On a positive note the SARS-CoV-2 reproduction number (number of people an infected person will infect) is down below 1.0, which if sustained would lead to a fall in cases and a flattening of the curve. The rate of positive SARS-CoV-2 tests in Ontario since the pandemic began is 1.84% but remains high at 3.7% today (although this is down from a peak of 5% ~2 weeks ago) (click here). 

map of north and South America graphs and tables with Ontarios data highlighted

Thus the pandemic is not currently well controlled with 13,779 active case in Ontario today including 586 hospitalizations (a 4.3% rate).

Ontario’s provincial rate (783.7/100,000 population) has doubled in the past month and is now almost 6X higher than in KFL&A (121.3 cases/100,000 population). However, for those following the local pandemic our prevalence has doubled since the summer! 

map of Ontario with highlighted areas of  high covid

Peel (on Toronto’s western border) is the hot spot in Ontario with 1580.9 cases/100,000 population. Toronto’s prevalence remains high at (1273.2 cases/100,000 population, up from 711 cases/100,000 population 2-weeks ago and ~10 times higher than Kingston) (see map below). Ottawa is also a hot spot at 804.5 cases/100,000 population (click here). To illustrate the stark regional differences in the pandemic in Ontario note the concerning case trends in the graph below in Toronto (magenta) and Peel (chartreuse) vs Ottawa (purple) and KFL&A yellow)-Nov 30th 2020 (click here).

graph of covid cases in Toronto, Ottawa, Peel and Eastern Ontario

The incidence of cases continues to be highest in young adults (age 20-29) (red part of graph below). In the past 2 weeks we are seeing a rise in cases in older adults. As has been the case throughout the pandemic, most deaths are still in people over the age 60, note gray part of graphs below (click here). There is similar incidence in males and females, except in those over 90 where we are seeing female predominance.

table and graphs showing covid -19 cases by age and gender

COVID-19 in Ontario by age and sex-Nov 30th 2020 (click here)

Neighborhood variation in COVID-19 in Toronto: Most of Toronto’s neighbourhoods are COVID-19 hotspots and have a cumulative prevalence of over 1000 cases/100,000 population (click here).

Toronto Skyline with CN tower

Toronto remains a collection of neighbourhoods with vastly different COVID-19 realities due to differences in social/economic, racial and health circumstances. Although COVID-19 is increasing in the city as a whole, case load is very high in some Toronto neighbourhoods. For example, Maple Leaf (highlighted on the map below) has had 4075 cases/100,000 residents, roughly 12X the burden of COVID-19 in the more affluent Beaches neighbourhood (320 cases of COVID-19/100,000 residents).

map of toronto area

When one examines recent cases (i.e. those diagnosed since Nov 4th), case prevalence is lower-although still concerning-ranging from 33 cases/100,000 residents in New Toronto to 1081 cases/100,000 residents, in Thistletown-Beaumont Heights. 

3) COVID-19 volumes have increased in KFL&A and we remain in YELLOW status (see update from KFL& A Public Health)There have been 17 new cases in the region since my note on Thursday. There are 25 active cases in the region, up from 16 on Thursday. The total number of cases since the pandemic began is now 262. All local COVID-19 patients are recovering in the community (see update from KFL& A Public Health).

graph of KFL&A covid data

KFL&A Nov 30th 2020

4) Canada’s second wave of COVID-19: 371,991 total cases, a rapid spike in infection in western Canada and Nunavut (click here)We have had 371,991 cases of COVID-19 in Canada and 12,040 deaths (see below) since the pandemic began. There are 64,242active cases in Canada today and 79.5% of all cases in the pandemic to date are recovered. There has been a 3.24% mortality rate amongst people diagnosed with COVID-19. Most cases of COVID-19 in Canada have been (in descending order), in Quebec, Ontario, Alberta and BC. Canada has done over 12.9 million tests and has a cumulative test rate positivity (since the pandemic began) of 2.86%. Ontario remains the province with the most testing.

map, table and graph if covid 19 cases in Canada

COVID-19 in Canada Nov 30th 2020.

Rates of infection are rapidly rising in all Western provinces (BC to Manitoba) whereas they are rising more slowly) in Quebec and Ontario. Rates of new infection are low in all Maritime provinces. There are new outbreaks in the North in indigenous communities in Nunavut (click here), which is very concerning given their very limited health care resources. Although Quebec still has a higher rate of test positivity than Ontario, its rate of case increase is flat and the total number of cases it accounts for, while still the greatest in Canada, is being approached by Ontario and Alberta (see graph below) (click here)

graphs of case data in Quebec

COVID-19 in Quebec Nov 30th 2020

5) The COVID-19 global pandemic exceeds 1.46 million deaths and almost 63 million cases, up 2 million since Thursday (click here): There are now 62,924,259 cases globally and there have been 1,462,989 deaths. The number of cases has increased almost 4-fold the beginning of August, 2020 when there were 16,296,790 cases globally. The pandemic hot spots are in the USA, India, Brazil, and Russia (click here). 

The USA with 13,399,855 cases and 266,986 deaths tops the COVID-19 list and accounts for ~21% of the global pandemic, while the USA only accounts for ~4% of the world’s population. USA positive test rates (click here): In contrast with Ontario’s ~4% rate of positive tests, the USA has an average rate of positive COVID-19 tests of 9.6% (a dramatic rise from October but unchanged from last week) (click here). However, rates of positive testing are a staggering 41% today in South Dakota and over 20% in Arizona.

ranking of countries with over 300,000 cases

For months I posted countries with more than 100,000 cases. Now, I am posting countries with over 300,000 cases and there are 33 of them!

6) The US-Canadian border will remain closed for routine travel at least until the December 21, 2020 and for other countries borders remain closed until Jan 21st 2021 (click here). Yesterday, the Honourable Bill Blair, Minister of Public Safety and Emergency Preparedness, and the Honourable Patty Hajdu, Minister of Health, announced that Canada will extend the Mandatory Isolation Order and temporary travel restrictions for all travelers seeking entry into Canada from a country other than the US, until January 21, 2021. Travel restrictions for US citizens and foreign nationals arriving from the US remain in place until December 21, 2020 and may be extended at that time. 

That said, Canadians can still fly to America (although certain rules apply) and as discussed in my note last week, Canadian citizens can return to Canada from America, with a number of requirements, including quarantine) (click here).

directional driving signs at the USA Canada border port huron

Regular reminders

KHSC bed capacity:  Not updated at time of note

Use the Mobile Screening Tool to expedite clinic visits: Complete the COVID-19 pre-screening tool here and you will be able to “skip the line”: One way to safely expedite entry of patients into our facilities is to have all patients complete our pre-screening questionnaire before their clinic visit. This will screen out people who are sick and expedite entry to the facility for everyone. Reducing lines waiting to enter the clinics will be particularly important as colder weather arrives. The mobile screening tool only takes a few minutes to complete and you will receive an email with confirmation to bring with you, along with your appointment slip, in printed form or on your mobile device. To complete the mobile-screening in English, click here and in French, click here.

screenshot of KHSC screening tool

KHSC visitor policy: One of the hardest aspects of COVID-19 care in the hospital is the need to restrict visitors to ensure we don’t import COVID-19 into the hospital. A very few cases of COVID-19 can paralyze the hospital, particularly if they are brought in by visitors and then spread undetected. All details on the policy can be found using this link (click here). 

COVID-19 testing at Beechgrove Community Assessment Center: (click here): All COVID-19 test must be scheduled appointments (versus walk in). Our online system, Coconut, launched today and will assist in contact tracing. Appointments can be scheduled by telephone or by our new Eventbrite on line scheduling system. Before booking a test, individuals should complete the online tool to determine whether they qualify for testing (click here). The Beechgrove Complex is south of the King St. West/Portsmouth Avenue intersection. Signage will direct people through the Complex to the Recreation Centre building at 51 Heakes Lane for walk-in testing. Operating hours: Testing hours will return to 9 a.m. to 4 p.m. daily. To be tested you will require: A valid Ontario health card or a piece of photo identification. You must also wear a mask and maintain physical distancing at all times while in the walk-in line.

transparent picture of a nasal covid-19 swab testthree young boys dressed up like doctors

Because health care workers (doctors and staff) are increasingly having to miss work because their children have been sent home from school or daycare with symptoms of a upper respiratory tract infection, we have arranged that their children can access expedited testing at Beechgrove . The goal of this service is simply to allow the healthcare worker to return to work as quickly as possible for the public good. The children of staff will be tested between 1230 -1300 by appointment, 7 days/week. The new program for families applies to children up to age 18, an includes children of staff and physicians who provide clinical care and service. Staff and physicians themselves should contact occupational health to book their testing appointment. To book an appointment for a child, KHSC staff should call 613-548-2376. Testing of clinical staff and faculty and their children is processed at the KHSC lab with an average turnaround time of less than 24 hours.

Increased outbreaks and deaths in Long Term Care facilities (LTC): We have 4060 LTC beds in KFL&A. As discussed in many prior notes, most COVID-19 deaths occur in people who are not only old but who are also frail and live in nursing homes and long term care facilities (LTC). As of today, the 2223 deaths in nursing homes (up 36 cases from Thursday) account for ~62.0% of all deaths in Ontario, click here. In the last month the rate of death amongst LTC residents continues to increase daily! Outbreaks in nursing homes usually start with a person in the community (health worker or family) acquiring the infection and importing it into the facility. Thus, protecting LTCs is best done with a combination of reducing community spread of COVID-19 and ensuring single occupancy rooms in LTCs (as well as appropriate pay for PWS workers, provision of PPE and rapid testing capacity).

COVID-19 in toddlers and young children: (click here). 

Fortunately kids remain much less likely to be infected by SARS-CoV2 and when they are infected they usually become much less ill (click here). The vast majority of upper respiratory tract infections in kids in Ontario are caused by other viruses, like rhinovirus and RSV. Thus, health policy makers and parents of young children should recognize that while children are not immune from COVID-19 infection, infections are relatively uncommon and outcomes are usually excellent for those who are infected. Nonetheless, we are about to prioritize children of healthcare workers for testing at KHSC so we can return the parents to work when children with symptoms (which will rarely prove to be COVID-19) are sent home from school or daycare.

two young boys in a classroom

Children are usually infected by an adult, usually in their home, rather than by other children. The number of cases in school age children (which includes teenagers) has increased dramatically to 2855 up over 182 cases from Thursday and almost triple the number from 3 weeks ago (985 cases). 

young female toddler holding an apple

Amongst younger children and toddlers COVID-19 remains relatively rare. In Ontario’s 5,500 licensed child care centres and over 120 licensed home child care agencies there is a very low COVID-19 burden (see table ). The rise in cases has been modest in these young children. 421 toddler age children have now been infected to date, up from 317 cases 2 weeks ago.

Stay well!

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