NACI recommends that the AstraZeneca/COVISHIELD or Janssen/Johnson & Johnson vaccines (once available) may be offered to Canadians 30 years of age and older if:
- The benefits outweigh risks of waiting for an mRNA vaccine.
- The decision to receive the vaccine is informed by risks and consequences of VITT.
- The delay to receive an mRNA vaccine is substantial.
NACI outlines that risk-benefit decisions should be informed by several factors including:
- The local COVID-19 epidemic conditions.
- Local vaccine supply
- An individual’s risk of severe illness and death if they develop COVID-19.
- And their risk of exposure to the SARS-CoV-2 virus.
Let’s look at what was behind the statements to understand the reasons for these statements. Maybe then we can give the Chair and Vice Chair of NACI a bit of a break.
I have said this before, the world of COVID-19 is an ever - changing landscape. Decisions by physicians, (on the delivery of care to COVID-19 patients), advisory agencies, and government agencies on a recommended course of action, are made with the data available at that time. That data changes and evolves. The ground shifts under our feet. Recommendations are made weighing Risk and Benefit.
March, 2021 NACI recommendations:
When the original NACI recommendations on vaccination using AZ vaccine were made, we were in the worst of wave 3. Vaccine supply in Canada was low..
3 % of Canadians were fully vaccinated, and 12% of Ontarians had received one dose of vaccine.
The pandemic was raging. Infection rates were climbing, hospital admissions were on the rise, Hospital ICUs were overflowing, the average age in the hospital and ICU (Intensive Care Units) was under 50. Unless emergent, the treatment of most other health conditions was on hold. There was simply no ability to provide additional care. The primary concern was to vaccinate as many people as possible to slow the rate of infection, reduce variant evolution, decrease the number of hospitalizations, ICU admissions and deaths. Pfizer ’s vaccine production was delayed, as was Moderna’s. The available vaccine was AZ. The protection against hospitalization, ICU admission, and death was comparable between vaccines (Pfizer, Moderna and AZ). At that time, (March 2021) VITT (or vaccine-induced thrombotic thrombocytopenia) was emerging as a risk, and the suspected numbers quoted varied between 1/200,000- 1/500,000, even 1/million. The consequences of this (as yet not clarified) event were however catastrophic. The overarching message to the public was - "we are actively monitoring to this serious issue" (recall from previous Help Me Rhonda that adverse reactions to vaccines are continually monitored and vaccine safety- “safety signal” is the highest level of concern) but “we need to get vaccine into lots of people”.
Fast forward to beginning of May 2021:
Many of the systemic issues remain- hospitals and ICU’s are strained with COVID patients.
1. 40 % of the population of Ontario has had one dose of vaccine. (now it’s 50%).
2. Safety signal.
800,000 Canadians have received the AZ vaccine to date. The “safety signal” on VITT is triggering more frequently in Canada, and over the world.
“Over last few days, there have been increased reports of VITT, with a rate of 1.7 per 100,000 doses administered," said Dr. Williams (Chief Medical Officer in Ontario). 12 Canadians have been reported to have VITT to date,, three of whom died. As more real-world data was shared, the VITT numbers continued to rise. Within a few weeks VITT numbers in the world were 1/26,000- 1/100,000. (this is case data ‘catching up') In Canada the VITT risk is now estimated at 1/50,000 (with some cases still being evaluated). The risk of dying from VITT is 1 in 5= 20%!
3. While many younger patients are very sick from COVID-19, their risk of death remains low, read here. Close to 25,000 people in Canada have died from COVID-19. 1.6% (375) are under age 50, and 3% (712) are people in their 50s, read here. Compare the risk of dying from VITT. It is 1 in 5-= 20%!
4. The risk -benefit of the AZ vaccine has changed. A personal risk for getting infected with COVID-19 has to be evaluated against the increasingly frequent, very serious risk of VTT and possible death (1 out of five).
5. COVID-19 "Hot spots” persist. “Hot spots” are both geographic and population based. Peel, Toronto, Durham, regions have high COVID-19 case counts. Furthermore, unvaccinated individuals employed in high risk environments, for example teachers, personal care workers, store employees, workers in the food / meat packing industries, etc, transportation industries, and youth are at high risk for exposure to COVID-19. If you are in these groups (page 11-13) and still unprotected you need vaccination. Your risk for infection with COVID-19 remains high.
6. AZ vaccine is NOT the only vaccine available. More Pfizer vaccine is arriving weekly. In fact, 2 million doses of Pfizer vaccine will arrive weekly now until mid-July. That is 20 million doses of Pfizer vaccine alone! True - distribution of the COVID-19 vaccine remains a challenge. To combat this and get at hotspots, Increased numbers of “pop up” clinics are dotting the landscape.
Dr. Andrew Morris (Infectious Disease physician, Professor Department of Medicine Faculty of Medicine University of Toronto, and Medical Director, Antimicrobial Stewardship Program Sinai Health System/University Health Network) paraphrases NACI and asks…"why would you take the additional blood clot risk when there are safer alternatives with the Pfizer and Moderna vaccines? And they are right. The caveat is if you have a really high risk of infection (see some of my reasons above) and you cannot access the mRNA vaccine (Pfizer or Moderna) get AZ vaccine”.
The belief that those individuals that received the AZ vaccine were given an inferior product or somehow hoodwinked into not getting a “lousy” vaccine is simply not true. To quote Dr. Andrew Morris. again, “In a raging pandemic, getting much, much, much safer with a vaccine that has a proven research and real life (Hello UK!) experience of protecting incredibly well from death or severe illness from COVID-19, when you had no other vaccine access, was the right thing to do. Rest assured. You are very well protected. So, up until several weeks ago, the aphorism "any first shot is your best shot” was correct".
What about the risk of VITT after a Second dose of AZ vaccine?
Does the second dose with AZ vaccine carry a different risk of VITT? I don’t’ know. Some reports have quoted 2 per million. Are these numbers accurate.? Remember VITT was not picked up in sufficient numbers to raise concerns about a connection to AZ vaccine until millions of doses were administered. There have not been enough second doses administered to evaluate this risk… NACI is tracking this data and will advise on it as well.
Expert opinion on further use of the AZ vaccine in Canada varies. Evaluating Risk/benefit data is complex. Dr. Morris believes that AZ vaccine should no longer be used in Canada, now that mRNA vaccines are in good supply. Dr. Rakowsky's (cardiologist UHN) comments are included here. NACI has stated mRNA are preferred vaccines, but left room for AZ vaccine use in specific circumstances. Each of us vaccinated with AZ vaccine, will now have to figure out where we stand on the second dose.
If you are 30+y, and belong to the high-risk group of individuals that are not yet vaccinated, you need to be vaccinated. iIt is now your choice which vaccine to take. You have heard the risks for VITT. You know the COVID-19 infection numbers. If you have a high risk of infection and you cannot get the mRNA vaccine, consider get the AZ vaccine. However, there is ample mRNA vaccine coming to Canada every week. If you are 18-29 y or less you are able to get the mRNA vaccine. At present, the AZ vaccine remains available to Canadians ages 30 and older.
It is only after the second dose of vaccine in all 3 vaccines (Pfizer, Moderna and AZ vaccine) that enhanced long lasting Immunity occurs (in all 3 vaccines).
This Study is looking at the following dosing schedules:
British study Com-COV - first study to look at vaccine combinations - is expected in June 2021.
- First and second dose of Pfizer-vaccine.
- First and Second dose of AZ vaccine.
- First dose of AstraZeneca-Oxford vaccine, second dose of Pfizer vaccine.
- First dose of Pfizer vaccine, and Second dose of AstraZeneca-Oxford vaccine.
On May 12 2021, the Lancet (a prestigious peer reviewed medical journal) reviewed some of the findings of combined vaccines in a preliminary communication (but not peer reviewed) of the data. This data is focused only on side effects from 4 weeks post vaccination and 12 weeks post vaccination in the above groups.Side effects such as feverishness, chills, fatigue, headache, joint pain, feeling unwell, and muscle aches were increased in the vaccine combinations compared to same vaccine dosing.There were no serious adverse reactions, no hospitalizations and most of the symptoms occurred within 48 hours of immunization and were short-lived. Paracetamol (like our Tylenol) use was more common.Further evaluation of side effects and effectiveness of "Mix and Match" vaccination is pending.