Dr. Theresa Tam has warned that a vaccine for COVID-19 will not be an instant "silver bullet" against the virus. 

The country's chief public health officer has said that safety measures such as physical distancing, mask-wearing and limiting crowd sizes could remain in place for the next several years. 

Tam used her briefing on Tuesday to send a clear message to people who believe that the creation of a vaccine will allow life to go back to normal straight away.

"We can't, at this stage, just put all of our focus [on a vaccine] in the hopes that this is the silver bullet solution," she said. 

"We're going to have to manage this pandemic certainly over the next year, but certainly [we are] planning for the longer term of the next two to three years during which the vaccine may play a role but we don't know yet."

Canada's top doc also discussed the potential distribution issues the country could face once a vaccine does become available. 

"It's likely that there won't be enough vaccines for the population, so there'll be prioritization and we're looking at that," she explained. 

Although Tam is "cautiously optimistic" that a vaccine will be available by the end of the year, she noted that public health officials are preparing for safety measures such as masks and social distancing to be kept in place for at least the next several years.

"[A vaccine] is one important layer of protection," added Tam. "It is a very important solution if we get a safe and effective vaccine, but I would say that the public health measures that we have in place — the sort of personal, daily measures that we take — is going to have to continue."