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graphs showing vaccine effectiveness

September 10, 2021 - Dr. Archer's Update on COVID-19 response from the DOM and Medicine Program

HEADLINES

1) All about the delta variant: The mRNA vaccines protected against the more infectious delta variant, which is now dominant form of SARS-CoV-2 in Canada 

2) Few reasons justifying medical exemptions to vaccination: Update on allergic reactions (Dr Ellis) and the CPSO guidance indicating that only proven anaphylaxis and myocarditis with 1st vaccine would preclude full vaccination.

3) KFL&A update: 28 local active cases (up from 9 last week), 0 KFL&A residents hospitalized and 78.6% of eligible residents (12-years and older) fully vaccinated (see update from KFL& A Public Health)

4) Ontario’s 4th wave: Despite >10 million people being fully vaccinated case rates are increasing by 4%/week (798 new cases yesterday), hospitalizations have risen 17% as well and there is a concerning 3.1% positive COVID-19 test rate (click here) (click here):

5) Canada’s COVID-19 4th wave: 11% increase in new cases and 27% increase in hospitalizations (driven by Western Canada) (click here) (click here)

6) World vaccine roll-out tops 5.6 billion people and safety record remains excellent (click here)

8) The global pandemic is not yet controlled: ~222 million cases with 4,547,761 deaths to datwith most deaths in the USA, India, UK and Iran (left column below)

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1) All about the delta variant: The COVID-19 vaccines protect against the more infectious delta variant, which is now the dominant form of SARS-CoV-2 in Canada 

There are different versions of the SARS-CoV-2 virus, each with a name from the Greek alphabet. Viruses constantly change (mutate) and these mutations may (or may not) alter their infectious properties or lethality. The dominant version of the novel coronavirus that causes COVID-19 is now the delta variant. It is called a variant because it has had genetic changes (due to evolution as it passes through human hosts). These mutations have changed the structure of one of the viruses 4 structural proteins, the spike protein. It appears that this mutation has made the delta variant more infectious, likely because the spike is better able to fuse with the ACE2 receptor that allows it to more rapidly enter and infect our lung cells. This subtle molecular trick is why this variant spreads so rapidly (in fact it now accounts for 95% of all new infections in Ontario). The graph below (panel C) shows the delta variants accelerated ability to fuse with cells (red line) compared with all other forms of SARS-CoV-2. Score one for the virus!

Colourful bar graphs

A likely explanation for why delta variant virus is more infective: it gets into our cells more rapidly because of a mutation in its spike protein (slide courtesy of Dr. Gerald Evans).

Thus far there is not much clarity as to whether the delta variant causes a more severe illness, although some data suggest it is more likely to doble the risk of hospitalization. In a study of over 43,000 cases in the UK it appears you are one is more likely to need hospitalization if infected with the delta variant (see below). Twohig et al showed “a 2.26-fold higher hospital admission or emergency care attendance risk for patients with COVID-19 infected with the delta variant compared with the alpha variant. Results suggest that outbreaks of the delta variant in unvaccinated populations might lead to a greater burden on health-care services than the alpha variant. Score another one for the virus! 

table of research data

Delta variants double the risk of hospitalization

The good news is that standard public health measures prevent the spread of delta variant (just as they blocked the spread of the original version of the virus). Wearing masks in indoor space, staying home when ill, physical distancing, hand washing all work! More importantly the available vaccines protect against the delta virus almost as well as they do again the original virus. However, this is only true once you are fully vaccinated; with a single shot the vaccines are 20% less effective against delta variant. Score one for humankind (at least for those who are fully vaccinated)!

graph showing vaccine effectiveness against variants

Vaccines protect against the delta variant-courtesy of Dr. Gerald Evans.

FYI UK—ChAdOx1 nCoV-19 is the Oxford–AstraZeneca vaccine and BNT162b2 mRNA BNT162b2 is the Pfizer–BioNTech vaccine

The take home message: Rather than worrying about the delta variant just ensure you and those around you are fully vaccinated and follow normal public health measures and you will be fine!

2) Few reasons justifying medical exemptions to vaccination Update on allergic reactions (Dr. Ellis) and the CPSO guidance indicating that only proven anaphylaxis and myocarditis with 1st vaccine would preclude full vaccination.

My colleague, Dr. Anne Ellis, representing the Canadian Society for Allergy and Clinical Immunology offers a reminder there are only two reasons not to offer a patient full vaccination related to allergy (and in most cases these reasons would only be invoked after a first vaccine): 1) anaphylaxis related to the vaccine first dose and 2) allergy to a vaccine component (see below).

note from allergist

The College of Physicians and Surgeons of Ontario (CPSO) likewise has advised doctors there are few legitimate reasons for medical exemptions, likely only including: 1) an allergist-confirmed severe allergy or anaphylactic reaction to a previous dose of a COVID-19 vaccine or to any of its components, and 2) a diagnosis of myocarditis or pericarditis after receiving an mRNA vaccine. You will note that these reasons for exemptions would preclude a second vaccine; not a first vaccine! 

So, if you are over 12 years of age and do not meeting one of these rare criteria-there is no reason to seek a medical exemption and your doctor should not grant such an exemption.

3) KFL&A update: 28 local active cases (up from 9 last week), 0 KFL&A residents hospitalized and 78.6% of eligible residents (12-years and older) fully vaccinated (see update from KFL& A Public Health). The local situation remains good, but you will see new cases are once again rising. This reflects unvaccinated people in our heavily vaccinated region. Herd immunity does NOT prevent an unvaccinated person from getting infected if they are exposed to the virus and even in vaccinated people, protection is only 90%. However, vaccinated people have extremely good protection (>95%) from death and hospitalization.

table showing current data for KFLA region re cases in step 3

The rate of positive tests in KFL&A remains low (1.08% positive); However, this rate of positive tests is up from 0.34% from the past week. The reality is that we live in Canada, where the 4th wave is rising, and are part of a global society, in which the pandemic continues to rage. I would anticipate that we will see a rise in cases this fall, due to the 20% of people that are unvaccinated, the rise in the delta variant, and the relaxing of mask policies. The good news is that this is a future we can influence and change; we just need to advocate for vaccination, ensure vaccination of younger children (once approved) and continue to use masks in indoor spaces. 

table showing current data in KFLA for vaccinations in phase 3

KFL&A residents have widely adopted vaccination!

The Medicine program at KHSC remains extremely busy with non-COVID-19 care. We are looking after 198 patients at KHSC. Clinics are continuing to ramp up toward pre-pandemic levels (although volumes are still limited by the size of waiting rooms and ongoing masking/physical distancing requirements). All physicians are being asked to see patients in person whenever possible and appropriate.

I can also reassure patients that all trainees, staff and faculty are required to be vaccinated to work at KHSC (see tweet below re new mandatory vaccine policy at KHSC). 

tweet screenshot with text and graph

The very few staff with medical exemptions to vaccination must wear appropriate PPE and are subject to mandatory twice/week testing. Thus, it is safe to come to Hotel Dieu and KGH to receive your health care.

4) Ontario’s 4th wave: Despite >10 million people being fully vaccinated case rates in Ontario are increasing by 4%/week (798 new cases yesterday), hospitalizations have risen 17% as well and there is a concerning 3.1% positive COVID-19 test rate (click here) (click here):

salmon coloured graph showing cases in Ontario for past few months

This data is concerning, especially when based on the trends seen elsewhere in Canada (where cases and hospitalization rates are on a more rapid rise). Most of wave 4 is driven by unvaccinated people, worsened by relaxing of public health policies. To keep our hospitals open for the care of the 99% of people who don’t have COVID-19 we will need ongoing mask policies, ongoing testing, improved rates of vaccination and vaccination of younger children (<12 years of age) as soon as it is approved. The good news is that with high rates of vaccination in Ontario we appear to be seeing a plateau in wave 4-although time will be required to see if this can be sustained (see below). 

line graph showing possible plateau in Ontario's wave 4

Possible plateau in Ontario’s 4th wave? Slide courtesy of Dr Gerald Evans

5) Canada’s COVID-19 4th wave: 11% increase in new cases and 27% increase in hospitalizations (driven by Western Canada) (click here) (click here)

Driven by unvaccinated people (particularly in BC, Alberta, Saskatchewan), the highly infectious delta variant, lack of vaccination approval for young children, and extreme relaxing of public health policy (in some jurisdictions): Canada is experiencing an 11% weekly rise in new cases and 27% rise in hospitalizations despite 67.9 % of the eligible population being fully vaccinated (click here) (click here). 

map of Canadasalmon coloured graph showing cases in Canada over the past few months

4th Wave in Canada Sept 9th 2021

We have had 1.53 million cases of COVID-19 since the pandemic began. The case mortality rate remains ~1.5% with 27,118 deaths. We administered 85,127 vaccines yesterday, bringing total jabs up to >53 million! There are 1690 Canadians in hospital today with COVID-19 (576 in ICU)! Alberta is providing a sad demonstration that this pandemic will not end without vaccination of all eligible people (see below).

various line graphs showing increases in all things covid in Alberta

The situation today in Alberta-rising cases, rising hospitalizations and almost 30% of their adult population unvaccinated!

Alberta has the lowest rate of vaccination amongst provinces and the highest case rate/100,000. These facts are directly connected one to another! The graph below shows that people who are not vaccinated drive poor public health outcomes: 

horizontal bar graphs showing vaccines and cases by province

This is a sober reminder-it’s not over, we are in wave 4 and sadly much of this pain is self-inflicted!

6) World vaccine roll-out tops 5.6 billion people and safety record remains excellent (click here). Canada remains near the top of international pack when it comes to vaccinating its population (see graph below).

dark and light green colours horizontal bar graphs showing populations vaccinated by country

Vaccines are safe: In addition to many clinical trials, the safety record of vaccines has been established in the real world, where we have administered 5.6 (+) billion jabs! The complication rates remain very low. There are also Canadian data showing that vaccines are safe (click here for Canada’s safety data), as well as being effective against all forms of the coronavirus. 

6 boxes with text and numbers

The serious complication rate in Canada remains low (7 serious adverse events/100,000 vaccines administered). Data as of Aug 27th, 2021

8) The global pandemic is not yet controlled: ~222 million cases with 4,547,761 deaths to datwith most deaths in the USA, India, UK and Iran (left column below)

satellite image of earth taken from spaceworld map with red dots, graphs and ranking lists of countries

Global COVID-19, Sept 9th 2021

Here is today’s map of the global pandemic. Daily cases are at a plateau (red graph), as are deaths (white graph). However, these are very high case load plateaus and the pandemic is not yet under control. Vaccine administration is somewhat down, which is concerning (green graph).

Final Thought

Please encourage your friends and family to get vaccinated! Unvaccinated people not only put themselves at risk; but when they fall ill, risk overwhelming our and blocking care for the 99% of people who do not have COVID-19. Unvaccinated people will also be a major pool in which the virus can circulate. This source of virus can potentially infect our children (under age 12 years), who are not protected since they are not yet eligible for vaccination.

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