TORONTO -- A potential COVID-19 vaccine in England offers some “hope for a change,” said infectious disease expert Dr. Abdu Sharkawy on Monday, but he cautioned that it’s still too early to know how successful the shot could be in stamping out the virus.

The experimental coronavirus vaccine out of Oxford University is “extremely promising,” said Sharkawy.

The vaccine candidate effectively produced antibodies that can recognize and kill an infecting organism in people aged 18 to 55, producing a dual immune response that lasted for at least two months after immunization, according to research published Monday in the journal Lancet.

“Usually when we say that there’s light at the end of the tunnel with COVID-19 we think it’s an oncoming train, but this might actually represent a little bit of hope for a change,” said Sharkawy, who spoke to CTV National News and CTV News Channel on Monday.

The vaccine remains in the early trial stages after testing began in April on 1,000 people. The sample size is set to get even larger as the trial expands to patients in Brazil, the United States and South Africa, three of the five nations with the most known COVID-19 infections worldwide. Meanwhile, there are more than 20 vaccines currently in clinical trials around the globe and more than 100 others in earlier stages.

The Oxford vaccine is considered so promising because it was shown to produce both “binding” and “neutralizing” antibodies, said Sharkawy.

“This is really the first time that we've seen a vaccine candidate that has been able to induce an immune response for what's called both binding antibodies that recognize the virus and neutralizing antibodies which can actually kill the virus, and they were able to sustain this effect after a booster dose given at 28 days,” he said.

In addition to the production of binding and neutralizing antibodies, there was no indication that the vaccine produced any harmful effects short of “minor aches and pains” that can be treated with Tylenol.

“A lot of the other vaccine trials had not-negligible side-effect profiles in terms of severe pain, febrile reactions, etcetera,” he said. 

But Sharkawy cautioned there’s still much work to be done before a vaccine is proven to be safe and effective. It has only been a few short months since the trial began and the pool of 1,000 people is too low and too young for full confidence.

“We need thousands more patients to be tested and to go through what’s called surveillance for longer-term safety before we can say that this is going to be readily accessible throughout the world,” he said. “We’re going to need data from that and beyond that we’ll need an infrastructure set up to distribute this if it continues to show the safety and efficacy results that it has. We still have to remain vigilant until that time with our hand washing and distancing and masking where necessary here.” 

What does the Oxford vaccine mean for Canadians? Not much.

“It means nothing just yet. It means absolutely nothing. This is a huge step in the right direction, it absolutely is. It’s terrific. We’re a lot closer than we were before,” said infectious disease expert Isaac Bogoch.

But phases one of two of clinical trials like this don’t provide the answer to the main question of everyone’s mind: “Does this protect me from COVID-19?” Those results likely won’t arrive until the end of the summer, said Bogoch.

Even when that answer comes, and if it is positive with the Oxford vaccine, it’s unclear what this could mean for Canada. The government has ordered enough syringes, alcohol swabs and bandages to immunize every Canadian twice, and Oxford and drugmaker AstraZeneca have committed to making 2 billion doses, it’s still up in the air what this means for Canada. It’s a bit “murky” as to how countries will obtain doses of a successful vaccine candidate.

“It’s not entirely clear which (vaccines) Canada will have access to. It’s not entirely clear what the global availability is,” said Bogoch. “Hopefully we can get our hands on some of them if it is successful.”