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tweet with 4 photos of Tim's card and nursing staff

May 6, 2021 - Dr. Archer's Update on COVID-19 response from the DOM and Medicine Program


Starting with a big Thank You to our nursing colleagues!

On behalf of the doctors and staff in the Department of Medicine Dr Chris Smith, Michelle Matthews and I have begun visiting the wards at KHSC and dropping of Tim Horton gift cards to the staff and nurses on medical wards and in the ICU (more visits coming next week). This small token is our way of saying thank you for your flexibility and professionalism and for the superb patient care you are providing under challenging conditions. There is no problem so big that it cannot be improved by a cup of coffee and a doughnut! 

tweet with photo of Tim's card and nurses

Helping India The Department of Medicine has collaborated with the Red Cross and set up a fundraising page to help support the Red Cross efforts on the ground in India. These efforts consist of providing awareness (COVID-19 education), hygiene items and handwashing stations as well as supporting the health care system and quarantine centres.

tweet for donation to India and a small photo of a boy getting a care pkg from the Red Cross


  • Provincial stay at home order (click here) in effect until the May 20th
  • All patients admitted to KHSC will undergo Covid-19 testing and all people entering the hospital will be required to wear medical grade masks.
  • Ontario Website now open to book vaccines for people over age 40 for all people and is now open for people ages 18-44 in hot spots (click here). 
screenshot of vaccine registration page
  • Universal masking: All patients and visitors to KHSC will be provided with medical masks at the doors of KHSC (to replace their cloth masks upon entry). Please wear your mask beginning on the front steps Do not enter the building without your mask on. Please be polite to the screeners-they are there to keep us all safe!

1) Transfer of patients with COVID-19 to KHSC from Toronto slows.

2) KFL&A update: New outbreak at construction site results in 34 new cases in Kingston (see update from KFL& A Public Health) (click here).

3) Health Canada approves Pfizer vaccine for adolescents (age 12-15 years) (click here).

4) Why you should take AstraZeneca Vaccine if offered-almost complete protection from COVID-19 death and 99.999% freedom from Vaccine induced thrombosis and thrombocytopenia (VITT) (click here).

5) World vaccine roll-out tops 1.21 billion people (click here)! The pandemic explodes in India and the Department of Medicine launches a Red Cross donation site (you can help-click here).

6) Ontario infection rates fall with 3424 new cases and a fall in positive test rates (6.8%); but hospital capacity remains saturated in Toronto (click here(click here): 

7) Canada’s COVID-19 epidemic shows a plateau in new and active cases (down -1 and -2%, respectively) and hospitalizations have plateaued (click here) (click here): 

8) The global pandemic continues to escalate: ~155 million cases to date and new case rates on the rise, particularly in India (click here): Up 5 million cases since last week!

9) COVID-19 Vaccines FAQ: New FAQ 1: Can I take a different second vaccine for COVID-19? (click here).

10) Continued Improvement in COVID-19 in Ontario’s Long Term Care facilities (LTC)…2 deaths in past week-evidence vaccines working:(click here).


1) Transfer of patients with COVID-19 from Toronto slows: As wave 3 begins to decline in Ontario we are seeing a decrease in the rate of transfer of patients with COVID-19 from the Toronto area. KHSC now has 31 patients with active COVID-19 in hospital (red bar-graph on left below). We are also caring for 21 individuals from Toronto who have recovered from COVID-19 (see green bar on graph below). We have adequate bed capacity (157 beds) and ventilator capacity (23 ventilators) to continue to support local care of patients. The Medicine program remains busy with 182 patients in hospital. Our new Johnson 3 ward at Hotel Dieu hospital is very active. I am extremely grateful to the faculty members and resident physicians who have stepped up and provided their support for this expanded bed capacity at a new site.

various colour graphs showing bed availability at KHSC

KHSC is busy but remains a safe place to receive non-COVID care with adequate bed capacity for local patients

2) KFL&A update: New outbreak at construction site results in 34 new cases in Kingston (see update from KFL& A Public Health) (click here).

There has been a new outbreak of COVID-19 amongst construction workers in Kingston. This is a reminder that until we are all vaccinated we remain as vulnerable to COVID-19 as we were last spring.

apartment building under construction

Currently 44.2% of the local population has received at least 1 dose of a COVID-19 vaccine (see below). KFL&A is prioritizing vaccination of construction workers, who are considered essential workers. The local goal is that everyone over age 18 in the KFL&A region should be vaccinated by the end of May!

table showing current KFLA data for phase two of vaccination roll out

Vaccination rates rising steadily in KFL&A

The total number of cases in KFL&A since the pandemic began is 1388, not counting the resolved prison outbreak or people from other regions. This is up 121 cases in the past week! There are now 128 active cases in KFL&A (see below). If you are not vaccinated you are not immune! Our test positivity rate is 1.47%. There have only been two deaths of KFL&A resident since the pandemic began but we have had several additional deaths at KHSC of non-resident patients. In Leeds Lanark Grenville county there have been 58 deaths with 8 deaths in Hastings-Prince Edward County. 

table showing current covid cases data for KFLA

The large number of local active cases is a reminder we are seeing active community spread.

line, bar and pie graphs showing variants strains in kfla

Most cases in KFL&A are due to variant strains of the SARS-CoV-2 virus (see above)

3) Health Canada approves Pfizer vaccine for adolescents (age 12-15 years) (click here)

two gloved hands holding a vaccine bottle

Young people are the age-group most often infected with COVID-19 (see below), even though they usually are asymptomatic or recover with only a minor illness. Until this week vaccination was only approved to people 16 years of age or older. This has now changed-which is a game changer for school re-openings.

blue and purple bar and line graphs showing counts and rates of covid cases by age group

Adolescents are often infected and develop COVID-19

Adolescents often spread the disease to older adults, who more often suffer severe health consequences, such as hospitalization (see below). Note the lack of hospitalization in people under age 19 years vs the high rates of hospitalization in people over age 40 years (graph below).

blue and purple bar and line graphs showing hospitalizations by age group

Vaccination of adolescents is critical to protect older adults, as well as the adolescents themselves, and is needed for stable opening of schools. There is now strong evidence that vaccinating young people is safe and effective. The first vaccine to satisfy Health Canada’s high standards is the Pfizer vaccine. Pfizer enrolled 2,000 adolescents between the ages of 12 to 15 in its U.S.-based trial, giving half that group a placebo and the other cohort the same vaccine that is used in adults. No vaccinated child in this study developed symptomatic COVID-19 whereas there were 18 cases of COVID-19 in the unvaccinated group. So when your adolescent has the opportunity they should get vaccinated. This will both quell community spread and allow sustained reopening of our schools!

4) Why you should take AstraZeneca Vaccine if offered-almost complete protection from COVID-19 death and 99.999% freedom from Vaccine induced thrombosis and thrombocytopenia (VITT) (click here)

The third wave in Canada is not yet controlled, we do not have adequate vaccine and quite frankly we do not have the luxury of not using the Astra Zeneca vaccine. If people make this choice there will be many unnecessary deaths and hospitalizations. The risks of the AstraZeneca vaccine causing VITT are rare…very rare! In contrast the benefits of the Astra Zeneca vaccine, which include an almost complete protection from COVID death and severe COVID disease, are substantial. The key point you need to know is that this rare complication occurs in 4/1 million vaccinated. Thus, 99.999% of vaccinated people will NOT develop VITT with the AstraZeneca vaccine.

The very rare cases where VITT occurs usually manifest 4 days - 1 month post vaccine. Symptoms include: persistent and severe headache, difficulty moving parts of your body, seizures, blurred or double vision, shortness of breath, or back, chest or abdominal pain or swelling/pain in a limb (click here). VITT is treatable and most patients affected have survived.

All drugs and vaccines have side effects that can cause harm or even death. Whenever a treatment is administered a doctor and a patient are essentially agreeing that the benefits outweigh the risks. In this regard, one needs to understand the magnitude of the risk vs the benefit. To provide some perspective on the low risk of developing this rare blood clot after the A-Z vaccine there have been five cases of VITT in Canada out of more than 1.1 million shots administered(two in Ontario, and one each in Alberta, Quebec and New Brunswick). 

The risk of developing a blood clot simply from being female far outweighs risk of developing a clot from taking a COVID vaccine. Women age 15-45 are more at risk for blood clots just based on their sex (1 in 3,300 risk of a clot). Many women choose to use birth control pills and this doubles their risk of clot to 1/1600. In contrast the risk of a clot after the Astra Zeneca vaccine is 1-4/million risk. Moreover, the vaccine will completely protect you from the much higher risk of contracting or dying from COVID-19. In the United Kingdom, where 20 million doses of AstraZeneca have been administered as of April 1st, there have only been 79 cases of blood clots likely linked to vaccination and <10% of these people have died (click here). The math clearly favours taking the vaccine. The Astra Zeneca vaccine has been reviewed again by Health Canada and its strong safety record has been confirmed. Health Canada once again recommends its use to stem wave 3 of COVID-19.

However, for those that are interested in how the vaccine might cause clots and whether the problem is the antigen or the vector-read on! There are 2 papers exploring the clotting disease that is associated in rare cases with the adenoviral vaccines (A-Z and J&J). 

Thrombotic Thrombocytopenia after ChAdOx1 nCov-19 Vaccination.Andreas Greinacher, al and Sabine Eichinger, M.D. New England Journal of Medicine, April 9, 2021. DOI: 10.1056/NEJMoa2104840 (click here). 

Thrombosis and Thrombocytopenia after ChAdOx1 nCoV-19 Vaccination. Nina H. Schultz, MD,PhD et al. and Pål A. Holme, M.D., Ph.D New England Journal of Medicine, April 9, 2021. DOI: 10.1056/NEJMoa2104882 (click here)

Both articles conclude that the unusual clotting events post vaccine are accompanied by thrombocytopenia (low platelet counts) caused by the unintended production of antibodies against a normal protein in the body (platelet factor 4 , PF4). These unwanted antibodies cause platelets to stick together and create blood clots in unusual places, like the brain, and they also reduce platelet counts which paradoxically promotes bleeding. The German study (see above) reported 28 cases of VITT, with a detailed description of the first 11 patients. They were aged 22-49 years and presented with serious thrombotic complications including cerebral venous sinus thrombosis (CVST), splanchnic vein thrombosis, disseminated intravascular coagulation (DIC), and pulmonary embolism. These problems occurred within 5-16 days of receiving the AstraZeneca vaccine. Six patients died. This group have now analyzed 40-50 cases, all of which show the presence of the PF4 antibodies. 

This combination of severe thrombosis and severe bleeding resembles another syndrome which is itself a complication of a widely used drug: heparin-induced thrombocytopenia (HIT). The new vaccine syndrome, named vaccine-induced immune thrombotic thrombocytopenia (VITT), and HIT are both diagnosed and treated in the same way, with the administration of intravenous immunoglobulins (IVIG) and anticoagulants. It is noteworthy we rely on heparin every day in the care of millions of patients; we did not discard it because of its ability to cause rare cases of HIT!

What about the Johnson & Johnson vaccine? The J&J vaccine resembles the AstraZeneca vaccine in that it uses an adenoviral vector to deliver the spike protein antigen. As with the Astra Zeneca vaccine the clot events with the J&J vaccine are also rare. We have not begun to use this vaccine in Canada but in the USA there have only been 17 cases of VITT out of more than eight-million doses of Johnson & Johnson's viral vector vaccine (click here). It is likely that VITT relates more to the vaccine vector than the spike protein antibodies since the 2 implicated vaccines use an adenoviral vector whereas all 4 vaccines generate antibodies to the spike protein and VITT has not occurred with Pfizer and Moderna vaccines, to my knowledge.

Updates: Canada has had 2 deaths attributed to VITT reported in a previously healthy 54 year woman, Ms Francine Boyer, in Quebec (click hereFollowing her vaccination, Ms Boyer suffered from severe fatigue and headaches. She was hospitalized locally and then transferred to the Montreal Neurological Institute but died two weeks post vaccination. Despite this tragic death the benefits of this vaccine, and all other COVID-19 vaccines, clearly outweigh the risks (discussed below). Since my last note a woman in her 50s died in Alberta (click here). Alberta has had 2 cases out of 253,000 vaccines administered.

The bottom line: It would be dangerous policy and poor personal decision making to avoid taking the AstraZeneca vaccine (which results in ~4 chances/million of causing a clot) while COVID-19 itself confers a 2% risk of death, a 5-10 % risk of hospitalization and both these bad outcomes are prevented by the Astra Zeneca Vaccine. The numbers clearly give clear guidance: Take the first vaccine you are offered! This advice is supported by Federal and provincial guidelines.

5) World vaccine roll-out tops 1.21 billion people (click here)! The pandemic explodes in India

colourful horizontal bar graphs showing overall world vaccine doses administered and then ranking by country

World vaccine roll-out tops 1.21 billion people (click here)! 

Vaccines are they key to ending COVID-19 and the graph above shows some vaccine champs (China in the lead). Canada’s vaccine roll out is slowly accelerating with >14.6 million doses administered. We are still paying a high price for our slow rollout in the form of an aggressive 3rd wave of COVID-19; but things are improving. There is real world evidence that the vaccines work. The graph below shows that in countries that have an effective vaccine roll out, like the UK and USA, rates of infection fall rapidly. In contrast, rates in India (where vaccinations are manufactured for export but few are delivered to Indian people) are skyrocketing (see below).The per cent of Indian people vaccinated remains low and the country is paying a high price with people dying rapidly. Suffering is intensified by shortages of basic supplies like oxygen.

colourful line graphs

The epidemic in India is a national and global crisis-note the low vaccination rate (left) and the rapidly rising rate of new cases (purple line on right).

The cause of the pandemic in India, as in most countries, is multifactorial. The epidemic reflects political dithering and ideology by leaders who deny the diseases’ magnitude and fails to plan for it. In addition India faces the stark economic realities of a country where poverty is common. Moreover, the emergence of SARS-COV-2 mutants, which are more infectious and probably more lethal. In addition, while vaccine nationalism is not in general viewed in a positive light; India has the opposite problem, massive export of vaccines to rich countries (like Canada) while the task of vaccinating their own population lags. India, has the world's largest vaccine-making capacity, and has donated or exported more than 66 million vaccine doses -it’s time to pay them back (click here).

The death rate in India (and this is likely an underestimate) is rising rapidly (see below).

line graph showing huge spike in covid 19 deaths in India

In light of this tragedy, the DOM has launched a fund raising site using Red Cross. If wish to join us in making a donation click here (tax receipt issued to you personally by the Red Cross.) I did it and it made me feel better!

Red Cross worker providing a care package to a young boy on his bicycle

India foreshadows what will likely happen in Africa. Very little vaccination has occurred in the African continent. We cannot end this pandemic without effective and equitable global vaccination. We need to turn our attention to international vaccine distribution as soon as possible.

6 text boxes with numbers and text

There is “made in Canada”, evidence that the vaccines are safe. Above are the Canadian vaccine safety data for all vaccines as of April 23rd (click here). After > 11.5 million vaccinations in Canada there have been 3,511 individual reports of vaccine side effects (0.03%). Only 617 side effects were serious (0.005% ) and there has been ~8 cases of VITT (estimated), of whom 2 people died. Among vaccinated Canadians adverse events was highest among those aged 18 to 49 (47.0%), and usually occurred in females (85.4%).

horizontal bar graph showing frequently reported side effects from vaccines

The common adverse effects of COVID-19 vaccination

The bottom line: If you get vaccinated you have less than a 5/100,000 risk of a serious allergic reaction and only one person has died from a COVID-19 vaccine in Canada. In return you get >90% protection from a serious COVID-19 infection and almost complete protection from a COVID-19 death. 

6) Ontario infection rates fall with 3424 new cases and a fall in positive test rates (6.8%); but hospital capacity remains saturated in Toronto (click here(click here): 

green number graphics with case trends in Ontario

COVID-19 in Ontario May 6th 2021: We are experiencing an encouraging drop in the 7-day rolling average of new cases, active cases and hospitalizations (see below).

salmon coloured bar graphs showing increase then decline of ontario cases

7) Canada’s COVID-19 epidemic shows a plateau in new and active cases (down -1 and -2%, respectively) and hospitalizations have plateaued (click here) (click here): 

map of Canada and surrounding bodies of watersalmon coloured bar graph showing increase and decline in cases for Canada

Stay home orders and vaccines work. Thus, it is no surprise that with stay home orders and rising vaccine rates in Canada we are seeing new and active case rates fall and hospitalizations plateau (above). We are not out of wave 3 yet but hospitalization rates are slowly starting to decline (see below). This will only be sustained if we follow public health rules while we await vaccination!

bar and line graphs showing covid data in Canada

COVID-19 in Canada May 6th, 2021

Canadians need to be aware that adherence to public health measures and acceptance of vaccines is critical. To date we have had 1,261,876 cases of COVID-19 since the pandemic began. The case mortality rate is 1.51% with 24,484 deaths. The current hospitalization numbers are much higher than in the 2ndwave of COVID-19 in late 2020 (with 4,154 people in hospital today). Most infections are being spread by close contact. We have done ~33 million COVID-19 tests with a cumulative positive test rate of 3.82%. We all need to do our part to keep the health care system afloat so that people who do not have COVID-19 can continue to receive essential health care. The state of hospitals is worse than at any point in the pandemic. 

Rates of infection are high in most Canadian provinces, although rates are most sharply increasing in Nova Scotia (see below).Alberta’s high rates have yet to plateau. Both Nova Scotia and Alberta have ordered much tighter public health rules and are enforcing them; this is the only defense to community spread until the vast majority of Canadians are vaccinated.

orange and green bar and line graphs showing increase in Nova Scotia covid cases

COVID-19 cases rise at unprecedented rates in Nova Scotia.

Canada’s vaccination roll-out: 14.8 million vaccines administered thus far (35.88% of population have received at least 1 dose) (click here)-see below: To date, 17 million doses of COVID-19 vaccines (including Moderna, Pfizer-BioNTech and Astra-Zeneca) have been delivered and 86.6% of delivered doses have been administered. Thus, Canada’s vaccine gap has narrowed compared with last week. This vaccine gap is most pronounced in Ontario. The gap reflects recent arrival of vaccines but also our relative inability to quickly administer the vaccine to patients. 1,191,359 Canadians are fully vaccinated (click here).

8) The global pandemic continues to escalate: ~155 million cases to date and new case rates on the rise, particularly in India (click here): Up 5 million cases since last week!

satellite image of earth from space

There have been almost 155.5 million cases of COVID-19 since the pandemic began, up almost 3 million cases since Monday! There have been 3,247,198 COVID-19 deaths since the pandemic began. Death rates are once again on the rise, as are new cases (orange graph below right). 

world map with yellow dots and ranking of countries with most global cases and deaths

New cases surge globally-orange graph bottom right, May 6th, 2021

This is a reminder of the need for global vaccination. We will not end this pandemic until the entire world has access to vaccines. Until then we will continue to have the development of mutant viruses that not only hurt the unvaccinated people but threaten to defeat the protection conferred by vaccination. 

The USA is a success story: The pandemic is improving in the USA largely due to an effective vaccine program, with over ~244,000,000 vaccinations completed and a promise to have all Americans vaccinated by the end of April, 2021. America now has a 3.6% positive test rate, the lowest rate since data collection began! (click here; see below). The American turnaround should offer hope to Canadians-this should be us in 2-3 months!

The UK is also a success (and they are embracing the AstraZeneca vaccine to achieve this success). Here is one of their rewards-safe mass assembly! (click here).

photo of maskless group of people in Liverpool attending a concert

Let’s get vaccinated so that Canada can safely party too!

8) FAQs-answers to common questions about the COVID-19 vaccines:

grey faceless human image holding hands up to head with orange questions marks swirling around head

New FAQ 1: Can I take a different second vaccine for COVID-19 (click here)

Chances are you can mix and match (i.e. one shot Pfizer; one shot AstraZeneca); but the science is not in yet. Researchers in Britain have launched a study to determine if it’s safe and effective to mix different vaccines (Pfizer and A-Z) that protect against SARS-CoV-2, the coronavirus that causes COVID-19. Participants will be allocated, at random, (rather like a flip of a coin) to receive one dose of one approved vaccine and a second dose of either the same approved vaccine, or a dose of a different approved vaccine. Participants will also be allocated at random to the timing of receiving these doses – some will get a boost dose four weeks after the first dose and some will get a booster at twelve weeks. Some believe that one vaccine type (mRNA vs adenoviral) may be better than the other in triggering the various aspects of the immune response. While we await the research results I would suggest taking the two doses of the same vaccine brand (but stay tuned for updates).

FAQ 2: I’m pregnant, should I get the vaccine? 

Vaccination is recommended for all women who are pregnant or breast feeding at any time in pregnancy unless there is some specific reason not to be vaccinated. The reason for this advice is that the mRNA vaccines for COVID-19 appear to be safe in pregnant women (click here) whereas COVID-19 has higher morbidity (is more severe) when contracted during pregnancy.

pregnant woman getting vaccine from health care workertweet of graphs showing safety for pregnant women getting vaccine

FAQ 3: New FAQ: Does one dose of vaccine provide protection from COVID-19? Short answer: yes (within 2 weeks). Pfizer vaccine confers 80% immunity within 2 weeks of first shot (click hereA real world study by the U.S. Centers for Disease Control and Prevention (CDC) evaluated the vaccines’ ability to protect against infection, including infections that did not cause symptoms. The study looked at the effectiveness of the mRNA vaccines among 3,950 participants in six states over a 13-week period. About 74 % of people had at least one shot, and tests were conducted weekly to catch any infections without symptoms. BothCOVID-19 vaccines developed by Pfizer-BioNTech and Moderna reduced risk of infection by 80% two weeks or more after the first shot. Immunity rises to >90% 2 weeks after the booster shot. This is reassuring, since Canada has spread out the interval from 1 month to 4 months, due to limited vaccine supply, as we try to get more people their 1st shot.

FAQ 4: If I have a solid organ transplant or I am a cancer patient should I have my second vaccine dose at the original interval? 

The short answer is yes (although it is not based on clinical trial data). Emerging “real world” data (aka experience) suggests that transplant recipients and active cancer chemotherapy patients (with specific treatment and timing considerations) are now eligible to have their 2nd dose of COVID-19 vaccine at the original interval (<30 days from dose 1); rather than the revised 16-week interval. KHSC is currently in the process of operationalizing this new recommendation (which was issued at noon today).

FAQ 5: Which vaccine will/should I get? The short answer is that all vaccines effectively prevent COVID-19 death and severe adverse outcomes-so take the one that you are offered. They are all safe. That said, the vaccine someone receives will depend on your age, where you live and where you are vaccinated. The AstraZeneca-Oxford vaccine, which has an overall effectiveness of 62%-vs >90% for Moderna and Pfizer, will be administered mostly through pharmacies and primary care clinics, as will the Johnson & Johnson vaccine (I suspect). This is the case because they both can be stored safely in a regular freezer (click here). The AstraZeneca vaccine is recommended for people between 18-64 years of age. The mRNA viruses (Pfizer/Moderna) are recommended for people over age 64 years. The advantages of getting a vaccine earlier (even if it’s a little less effective) outweigh waiting longer for a more effective vaccine. This is especially true since all vaccines seem to prevent death and severe COVID-19 complications. Emerging data show that the Astra-Zeneca vaccine is safe and effective in people over age 70 years (based on real-world data emerging from its use in the UK) (click here). In the recent US study it was over 90% effective in preventing severe COVID-19 and prevented death with 100% effectiveness!

FAQ 6: Which COVID-19 Vaccines have been approved by Health Canada? Currently Canada has 3 approved vaccines: Pfizer, Moderna, and Astra-Zeneca (as of last week). The Astra Zeneca vaccine was approved on Friday and may arrive as soon as Wednesday (click here). Canada is expecting 445,000 doses of this vaccine this week. The vaccine appears to prevent COVID-19 spread and severe COVID-19 pneumonia and death; however, it has the lowest effectiveness overall (62% protection).The J&J vaccine was just approved by the FDA in the USA (click here). It has not been approved in Canada yet but this is expected to occur in the next 2-3 weeks. The J&J vaccine has several advantages. In a study with people in 3 continents one dose of J&J was 85 per cent protective against the most severe COVID-19 illness and the safety profile was as good as other vaccines. The J&J vaccine is a single shot vaccine (unlike two shots for Pfizer and Moderna). In addition it can be stored in a simple office refrigerator, allowing it to be rapidly deployed in the community. The bottom line: All approved vaccines are protective against severe adverse outcomes and I would advise you to take the first vaccine you are offered!

FAQ 7: Does the vaccine work against new variants (mutations) in the SARS-CoV2 virus? Short answer is a qualified YES. The vaccines work albeit not quite as well for the variants. In the 144,000 participants in all randomized clinical trials of vaccines to date, those receiving any active vaccine had only 3 cases of severe COVID-19 (vs 37 in the control group). There were no deaths in people who were vaccinated with any of the vaccines versus 5 deaths in the control group. Even though absolute protection is slightly less for UK and South African variants the vaccines (including the AstraZeneca vaccine and J&J) prevent serious adverse outcomes (like hospitalization and death). Thus, despite variant viruses the vaccines are lifesavers!

FAQ 8: I’m on a blood thinner, can I be vaccinated for COVID-19? Short answer YES. Here is a more detailed answer from an Canadian agency with expertise on the use of blood thinners, Thrombosis Canada

memo from thrombosis canada re vaccine safety

FAQ 9: I have a history of allergic reactions, can I be vaccinated for COVID-19? Short answer YES. Out of ~1.8 million vaccinations there have only been 21 reported episodes of anaphylaxis (the most serious type of allergic reaction). Most (70%) of these events occurred within 15 minutes of the vaccine (which is why you will be monitored for this period of time post vaccine). There were also 83 cases of non-anaphylaxis allergic reaction after Pfizer-BioNTech COVID-19 vaccination with symptom onset within a 0–1-day risk window. Most (87%) of these allergic reactions were classified as nonserious. Thus, the risk of severe allergic reactions to the Pfizer vaccine are low and manageable. Allergy testing is NOTnecessary prior to COVID-19 vaccination even in people with history of allergies. It is important note that none of the people who developed anaphylaxis after vaccination died and most did not have a prior history of anaphylaxis (see table below). The incidence of anaphylaxis is lower still with the Moderna vaccine. The Canadian Society of Allergy and Clinical Immunology has recently updated and reinforced this advice (see Tweet below):

tweet outlining vaccine and allergies

The adverse effects of the COVID-19 vaccines in clinical trials are similar in vaccinated people vs people who got a placebo-saline injection except for: local pain at the vaccine site and increased muscle ache and headache, all of which were more common with the vaccine but were short-term (see below). This is a very good safety profile relative to other vaccines.

table comparing Pfizer vaccine side effects to placebo

The CDC does advise against the use of the two mRNA vaccines for a very select group of people with the following allergy histories (click here):

  • Severe allergic reaction (e.g., anaphylaxis) after a previous dose of an mRNA COVID-19 vaccine or any of its components
  • Immediate allergic reaction of any severity to a previous dose of an mRNA COVID-19 vaccine or any of its components (including polyethylene glycol [PEG])*
  • Immediate allergic reaction of any severity to polysorbate (due to potential cross-reactive hypersensitivity with the vaccine ingredient PEG)*

FAQ 10: I’m immunosuppressed, should I get vaccinated? This question has a less clear answer. First, be reassured is no virus (dead or alive) in the Pfizer or Moderna vaccines so it is not possible for a person to get infected from the vaccine. However immunosuppressed people were not included in the initial clinical trials. That said, they probably are safe to be vaccinated but this is more a matter of expert opinion. In Canada the National Advisory Committee on Immunization (NACI) currently advises that the COVID-19 vaccine should not be offered to populations excluded from clinical trials “until further evidence is available.” However, they also say “an immunosuppressed person or those with an autoimmune disorder can still be vaccinated if a risk assessment deems that the benefits of vaccine outweigh the potential risks for the individual.” (click here).

The British Society for Immunology recently issued a statement indicating that vaccination is safe in immunosuppressed people (click here), albeit the resulting immune response may be weaker. They remind us that because there is no virus in the vaccine there is absolutely no risk of acquiring COVID-19 from the vaccine. Dr. Mike Beyak (gastroenterology) nicely summarized evidence from a registry of ~4500 patients who were immunosuppressed for their inflammatory bowel diseases (Crohn’s disease and ulcerative colitis). There was no increased risk of contracting COVID-19 in these 4500 patients. Apart for patients on prednisone, there was also no increased complications from COVID-19 when it occurred. Interestingly, some biologic therapies (antibody treatments for IBD) actually appear to reduce adverse outcomes in IBD patients who contracted COVID-19. This is not surprising since the truly bad outcomes in COVID-19 seem to occur in people who mount a hyper-aggressive immune response. Overall these data are good news for our many patients with rheumatoid arthritis, asthma and IBD who are on immunosuppressive therapies. However, since these people were not included in the vaccine clinical trials, it is advised they consult the physicians/clinic that is managing their care to inform their vaccine decision.

FAQ 11: How long can I wait after my first dose to get a second vaccine dose? It appears a second dose at day 42 is as effective in producing a neutralizing antibody response as when the dose is given at day 21 (the normal interval from dose 1). This more lenient 42-day interval is necessitated by our vaccine shortage and has been approved by Health Canada. 

syringe with needle drawing vaccine from bottle

FAQ 12: Can I contract a COVID-19 infection from the vaccines? This answer is simple-NO! None of the approved vaccines in Canada contain the virus itself. They do not contain live virus; they do not contain dead virus. Canada’s approved vaccines (from Pfizer and Moderna) contain only the messenger RNA (genetic code) to allow you cells to make the viral spike protein which then triggers your immune cells to build anti-spike antibodies which protect you. The Astra Zeneca vaccine is much the same but delivers the SARS-CoV-2 spike protein gene via a chimpanzee adenovirus-vector. The J&J vaccine also uses an adenoviral vector but again, there is no SARS-CoV-2 virus (not dead; not alive) in this vaccine (click here). So, while you might get a sore arm or a fever from vaccination this is just your immune system responding as it should; there is no chance of getting COVID-19. Obviously one could contract COVID-19 around the time of vaccination the normal way, before the vaccination’s protection develops (i.e. in the first 2 weeks after vaccination). 

FAQ 13: Are vaccines safe? Yes, serious adverse effects of vaccines are rare (occurring in only 167 of 1.4 million Canadians vaccinated). Most people get (at worst) sore arm at the injection site, fatigue, or fever, all signs the immune system is being activated. Based on the clinical trials and experience in millions of people who have been vaccinated world-wide we can be reassured of vaccine safety and efficacy. All the side effects (called adverse events and abbreviated AEFI) are tracked and reported by the government of Canada (see below). (click here) (last updated April 16th).

FAQ 14: Is it safe to increase the time span between dose 1 and 2 of the COVID-19 vaccine? Most vaccines are given with an initial dose and a booster dose 3 months later. The reason the COVID-19 vaccine regimen initially specified a shorter interval was simply the rapid pace of the clinical trials which compressed the vaccination interval. Regulators approved the vaccine based on the information that came from these trials. With time it is now clear that spacing out the interval up to 4 months is safe and effective. This longer interval between vaccines allows more people to get the first dose asap and as the data have shown, the first dose yields substantial immunity within 1-2 weeks. That said, once vaccines become more available it would be prudent to return to the initial interval between vaccine doses. My second dose of Pfizer vaccine will occur 4 months after the first dose I received.

9) Sustained improvement in COVID-19 in Ontario’s Long Term Care facilities (LTC)…evidence vaccines working: click here.

three senior citizens all wearing masks sitting around a table

Most COVID-19 deaths occur in people who are not only old but who are also frail and live in nursing homes and LTC facilities. While LTC residents account for only 5.3% of all cases in Ontario, they account for 51.8% of all 8029 deaths in Ontario. As of today, the 3,762 deaths in nursing homes account for ~46% of all deaths. There were 5 new deaths in LTCs due to COVID-19 in the past week. There are 62 active COVID-19 cases in LTC residents and 163 active cases in LTC staff, the lowest numbers in months. These numbers remain low and stable, which is testimony to the effectiveness of mass vaccination in a high risk population! For example a month ago we were seeing death rates of >100/week; now it is 0-5/week. The graph below shows the beneficial impact of the province’s decision to prioritize its limited initial vaccine supply of health care workers and residents of Ontario’s LTCs. Note the rapid decline in both staff (yellow) and resident (orange) COVID-19 case numbers coincident with vaccination!

line graphs showing decline in cases in LTC after vaccines were given

Now this to friends and family who are vaccine hesitant: Vaccines crush COVID-19 in LTCs: an awesome testimonial to the power of vaccines in vulnerable people

Regular reminders-On hiatus 


Stay calm, Stay informed, Stay Home, Stay Well! …. Get Vaccinated!!!

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