What’s in a number? Let’s discuss vaccine efficacy.

What exactly is vaccine efficacy? Efficacy is a measure of how well a vaccine works in clinical trials – specifically, the percent reduction of disease by comparing two groups – one that receives the vaccine and one that doesn’t, under favourable and tightly controlled settings. However, how one measures efficacy can vary significantly. Within the

NACI AstraZeneca Guidance – Suspend Use in Younger Than Age 55

Small increased risk of rare types of blood clots accompanied with thrombocytopenia (low platelets). Called ‘vaccine-induced prothrombotic immune thrombocytopenia’ or VIPIT. VIPIT is very rare. Initial estimates from Germany were 4 per million. Subsequent Norwegian estimates are 42 per million. Per Science Table estimates: occurring in anywhere from 1 in every 125,000 to 1 in

AstraZeneca Infographic

I have been getting a lot of questions on the AstraZeneca Oxford vaccine, and while data is evolving, here is some information Dr Elisabeth Marnik and I put together on its efficacy and safety. So far, it is very effective in preventing severe illness, hospitalization and death – both from clinical trial data as well

NACI – 4 month dosing delay

I’ve received many questions on NACI’s most recent recommendations on delaying second doses up to 4 months. This is a complex topic, but I think important to discuss for transparency. The only absolute in science is that there are no absolutes. Throughout the pandemic, evidence has evolved and recommendations have changed based on new data.

J&J – Approved by Health Canada

Johnson and Johnson’s COVID-19 vaccines becomes the 4th to receive Health Canada approval!  85% effective in preventing severe illness, 100% effective in preventing hospitalizations. Single dose, with data on efficacy in variants as well as preliminary data against asymptomatic disease. Best part – storage 2-8C. Will be a very valuable tool in our arsenal against

Variants of Concern

Here is an infographic showing the current variants of concern and the subsequent data on the vaccines. We currently have lab based data available, but expecting to see human trial data shortly. We do not expect to see as drastic a decrease (eg 6 fold) in efficacy given that neutralizing antibodies are only one component