Thread by @tara_kiran

I want to start by acknowledging the confusion and frustration that the latest NACI statement has caused those who got the AZ vaccine—and the pharmacists and primary care clinicians supporting them

As I write, I know many are on the phone rescheduling appts

A few thoughts 🧵1/

NACI has said that an mRNA vaccine is preferred as the 2nd dose for those who received AZ for their 1st

They also reassure folks who got AZx2 that they have very good protection against severe death and hospitalization 2/

canada.ca/en/public-heal…

Their recommendations are based on emerging data on immunogenicity and safety

@SabiVM does a great job of summarizing the immunogenicity data here. Note we have no data on effectiveness (ie Covid outcomes) 3/

The safety worry is VITT (serious blood clots). The risk seems to be 1 in 600K after 2nd dose AZ (much lower than 1st dose risk). The risk is zero with mRNA 4/

The evidence supporting the NACI statement doesn’t seem to have changed much in the last two weeks.

We laid much of this out in this decision aid we released 10 days ago designed to help patients and providers navigate uncertainty 5/

uwaterloo.ca/pharmacy/sites…

For me, the timing, wording, and communication of the NACI statement is what’s confusing & frustrating

What does NACI mean by “preferred”? How strong a preference?

The sentiment seems easily interchanged with “should” in press conferences which has a different implication 6/

Ideally, the statement NACI issued would be accompanied by patient-facing material that walks people through the evidence and helps providers effectively counsel patients 7/

I realize timing is always tricky in a pandemic but I’m also not clear on the rush to publish the statement given there is no effectiveness data and risks of VITT after second dose are unclear. Evidence continues to evolve and there is a lot of uncertainty 8/

Frustration is of course compounded by Ontario only just opening up 8 wk 2nd doses to those with AZ. Many patients/pharmacists/primary care clinics just rejigged schedules. Now they are rejigging again 9/

I have huge respect for the individuals working with NACI. Now, >15 mo into the pandemic, they really need to be supported by savvier comms. They would also benefit from welcoming more members of the public, pharmacists & primary care clinicians to their deliberations 10/

I’ll end though as I started, acknowledging those who stepped up to take AZ—helping us achieve the highest rate of 1st dose coverage in the world—and the pharmacies and primary care offices answering their calls right now. 🙏🏽🙏🏽🙏🏽