By Allison Lampert and Julie Gordon

(Reuters) - Canadian automation company Promation had been banking on a weaker currency to help it win a new U.S. contract, but a slower pace of vaccinations in Canada could erase that competitive edge, President Darryl Spector said.

Pandemic travel restrictions make it harder for Promation’s technicians to travel across the border to service and repair plant equipment, a drawback when competing against an increasingly vaccinated U.S. workforce.

"With a fully vaccinated U.S. supply base, why buy from Canada if you can't access the labor to support it?," said Spector.

To prevent spread of the coronavirus, the U.S.-Canadian border has been closed for nearly a year to crossings by all but essential workers and a handful of other exceptions. In Canada, manufacturers fear the slower vaccination rollout could delay an easing of those restrictions.

U.S. President Joe Biden told states on Thursday to make all adults eligible for a coronavirus vaccine by May 1. Canadian Prime Minister Justin Trudeau has set a September target for having all Canadian adults vaccinated.

In the United States, some manufacturing workers are already receiving inoculations, such as in Detroit-area auto plants. By contrast, general manufacturing workers like those at Spector's Ontario-based firm, are not eligible in Canada yet.

The lag handicaps Canadian firms, they said, and may threaten Canada's economic rebound in coming months.

While the recovery has picked up pace, the Bank of Canada warned on Wednesday the virus will continue posing a risk to the economy until the population is widely vaccinated.

U.S. health authorities have issued guidelines exempting asymptomatic vaccinated workers from strict COVID-19 protocols in case of exposure, but Canada has not yet considered similar action.

That leaves Canadian firms at greater risk of lost working hours or shutdown for COVID-19 tests and contact tracing if an employee tests positive.

"People can't work as easily together if they are looking over their shoulder in case someone has COVID," said Spector, who recently sent eight workers home and covered the costs of their test results when an employee's wife tested positive.

Matt Poirier, director of trade policy for Canadian Manufacturers & Exporters, said his association has asked provincial governments to prioritize factory workers for vaccination to curb the impact of outbreaks on plants.

As of March 10, Canada had administered 7.20 COVID-19 vaccine doses per 100 people, compared with 29.67 in United States, according to University of Oxford data.