Even the tightly controlled system for handling precious COVID-19 vaccines can’t avoid it completely, at the end of the day: wasting some doses.

Quebec, a week into its mass vaccination campaign, is trying to cut down on instances where appointment no-shows or other problems mean unused doses get thrown out.

One solution? Have a backup list at the ready, a provincial spokesperson told CTV News on Tuesday.

“Some establishments operate with waiting lists, in particular of healthcare workers,” said Marie-Hélène Émond from Quebec’s health ministry.

“Different means can be used to administer the few remaining doses at the end of the day,” she explained, mentioning that “staff” or “attendants” can be the lucky recipients.

In Quebec, “attendant” can refer to orderlies who work in health-care settings.

One of the largest Montreal health districts keeps a list of people ready for last-minute vaccinations on hand, too.

"We have a backup list of health care workers and vulnerable residents of our territory who we call if we have extra vaccines at the end of the day due to cancellations or no-shows," said Barry Morgan, spokesperson for the West-Central Montreal health authority.

"We are determined not to waste a dose."

Only a few days into the drastic ramping-up of vaccination numbers, there are only a few anecdotal reports of vaccine doses getting wasted, health authorities say.

It can happen for various reasons, and not just no-shows. But the province’s account of its process meant to avoid spoilage also underscores why showing up to appointments as scheduled is so crucial.

“The entire operation of transport, storage and administration of doses is a highly strategic and delicate operation,” said Émond. “Many means are in place to avoid wasting doses.”

Before the vials go out for delivery, they’re prepared according to the exact number of people scheduled to get shots on a certain day at a certain site, she said. The number of staff on hand is also calibrated accordingly, to make sure there will be enough people to handle the vaccines.

“Deliveries are then planned and supervised,” she wrote. “The doses are stored frozen. They only came out of the freezer on an as-needed basis.”

There’s great pressure to make use of every dose, and not just for cost reasons. This week, for example, cancer doctors were in the news, pleading with the province to vaccinate their patients at the same time as the elderly because of their fragile health.

The province is contending with a raft of other difficult decisions about who to move slightly up or down in the priority list, including people with Down syndrome, teachers, and people who work frequently with the public, like cashiers.

Aside from no-shows, there have been other reasons for wasted doses so far, said the province, though it’s rare. That can include dropped vials, said Émond.

“Obviously, we are never completely safe from human error…it is an inevitable reality,” she said.

But “it should be noted that nearly 440,000 doses of vaccine have been administered to date and some exceptional cases [of wasted doses] that have been reported to us remain anecdotal,” she said.

When doses are lost, the incident may not be mentioned publicly, but it’s reported internally, said a local health authority.

“Loss of doses turns out to be extremely rare, and the few times it has occurred, the event has been documented and reported to pharmaceuticals,” said a spokesperson for the West Island health authority.

The West Island system “ensures very tight management of vaccination doses in order to ensure that as many people as possible are vaccinated. We use the same management protocols as for narcotics,” she said.

One other potential reason for wasted doses falls into a different category: the use of the infamous five-dose syringes with the six-dose Pfizer vials, which end up wasting the sixth dose of every vial.

One Montreal man said he was told last Thursday that he could be vaccinated as an “extra” at Maimonides care home in Cote-St-Luc after arriving with a large group of elderly care-home residents—only to be called just before the appointment and told the extra dose was no longer there.

Those who did get their vaccines later told him it was because the five-dose syringes were being used, and they saw the extra doses thrown out.

But the West-Central health authority, which oversees that vaccination centre, said that wasn't the case. If the predicted extra dose didn't materialize, it was for other reasons.

"There is no shortage of vials and no doses were wasted," said Morgan, the CIUSSS spokesperson. He said there's been no problem with six-dose syringe procurement.

Canada had struggled earlier this winter to procure enough of the six-dose syringes, but Émond, speaking for the Quebec government, also said the province has enough on hand now.

“There is no issue regarding the availability of low-dead-space syringes,” she said.

“The [ministry] is receiving sufficient quantities since the changes in the way doses are counted.”