The coronavirus vaccine candidate being developed by Pfizer (PFE -2.80%) and BioNTech (BNTX -2.09%) is now undergoing its first regulatory review in North America. The two companies announced that their BNT162b2 has been accepted for a rolling review by Health Canada, that country's healthcare regulatory authority.

A rolling review is one undertaken while a candidate is still in development; this is done in cases of urgent need, as with the current global pandemic.

A coronavirus cluster.

Image source: Getty Images.

No estimate was provided as to when Health Canada might complete its review; the two companies wrote that the regulator "will not make a decision on whether to authorize any vaccine being considered under rolling review until it has received the necessary evidence to support its safety, efficacy and quality."

BNT162b2 is currently in phase 3 clinical trials, having reached that stage relatively quickly. As such, it is considered by many observers and pundits to be the leading COVID-19 vaccine candidate for approval.

According to Pfizer and BioNTech, around 37,000 participants have been enrolled in more than 120 testing sites around the world in the trials. Twenty-eight thousand of those patients have received the second dose of the two-dose vaccination.

Meanwhile, Pfizer and BioNTech continue to get their ducks in a row regarding the manufacture and distribution of BNT162b2 should it be approved for use. On Monday, the pair said they've signed an agreement to supply 1.5 million doses to New Zealand. The financial terms of the deal were not specified.

In mid-afternoon trading Monday, Pfizer's shares were up by 0.3%, lagging the gains of the S&P 500 index. BioNTech's stock was down marginally.