HALIFAX -- Several recent COVID-19 cases in Nova Scotia have no clear link to travel or a known COVID case. That has the province’s top doctor concerned about community spread and the fact many people who recently tested positive have been socializing more.

"We have to end up with the conclusion that quite likely we're seeing some early signs of community spread," said Dr. Robert Strang, the province's chief medical officer of health. "Our case numbers are going up, the numbers that we don't have a clear explanation in is growing."

Strang says recent COVID-19 cases have concerned him after learning the individuals have had very active social lives, and tend to go out multiple times per week.   

"We cannot have people going out multiple times in a week, each time with different people. We need to still remain very cautious about our social activity because it's social activities which is the main way that spreads this virus,” said Dr. Robert Strang, the province's chief medical officer of health, in a news conference Wednesday afternoon.

"Each of us needs to look at, who do we have to be in close contact with within our home and work, and we should really be limiting the number of other people to very small numbers right now outside of those essential contacts."

"Every single person's actions make a difference here and I am genuinely concerned this week,” said Infectious Disease Specialist Dr. Lisa Barrett.

She says it’s critical to keep testing rates high in Nova Scotia so we can keep our case numbers low.

"Getting tested every week or two, depending on what your risk is, or once a month if you really and truly see no other people is very reasonable. But please consider, especially with some new cases in the community and the chance of community spread, please consider regularly getting tested,” said Barrett.

"There's many people who just don't seem to be getting the fact that we're still in a pandemic and we still have to be very careful about the number, and people, and how we get together with other folks outside of our families," said Strang.   

While health officials work to curb the spread of the virus, the Canadian National Vaccine Safety Network has started a web-based survey to track any potential adverse reactions to COVID vaccines.

"This is really going to provide us with detailed data, information about what common, uncommon and rare side effects or health issues we can see following the vaccination. It's a rapid way to gather information to identify any safety concerns that might arrive as we roll out these vaccines to millions of Canadians," said Dr. Karina Top, associate professor of pediatrics and community health and epidemiology at Dalhousie University.

Investigators aim to enroll 300,000 participants per vaccine across Canada. Participants will be asked to complete online surveys eight days after they receive the first COVID-19 vaccine, another eight days after the second dose, if they receive one, and then a final survey six months after that. Non-vaccinated participants will need to complete up to three surveys. These surveys will estimate how much illness is expected in the community. Once those in the non-vaccinated group receive the vaccine they may fill out the vaccine surveys.

"With every new vaccine program that's rolled out and even with existing vaccine programs, we monitor safety closely and so we're essentially scaling up systems that were already in place to better monitor the COVID vaccines,” said Top.

Those interested in learning more about the survey can go to canvas-covid.ca