(CBS4) – The original coronavirus, SARS-CoV-2, has mutated several times, raising concerns about spread, symptoms and the efficacy of vaccines. CBS4 Medical Editor Dr. Dave Hnida spoke about those concerns this week in an interview on CBSN Denver.

One strain, the so-called UK strain, has already been detected in Colorado. There is also the South African strain and scientists are monitoring other changes. It is believed both of those named strains are more contagious.

“They do not induce some severe illness as we would worry that a mutated strain might,” Hnida said. But he pointed out if they are more contagious they do still pose a risk to people who are high risk and predisposed to getting severe COVID. That could overwhelm the hospital system.

“We do know from preliminary testing at least the Pfizer vaccine is effective against one of the mutated strains,” he said. “Most likely the Moderna vaccine is the same situation.”

But he pointed out there are new worries about testing.

“We are concerned that the strains of these mutated viruses may wind up producing a false negative result with certain types of testing,” he explained.

“What we’re hoping is that we can increase what we’re doing in terms of genetic sequencing. Keep an eye on how these strains are spreading through Colorado as well as the rest of the country.”

“In the United States, in one week we typically get about 1.4 million positive tests. We’re only genetically testing about 3,000 — far too little to have any sort of clue about what these strains are doing.”

Hnida said the federal government needs to work with states to provide funding for more genetic testing.

As for the efficacy of vaccines going forward, Hnida said it’s believed coronaviruses in general typically take about three years to mutate to a point where a vaccine would be ineffective.

“This is different than an influenza family of viruses,” he said. “Those mutate within a year. That’s why we need an annual flu shot.”

“In this particular situation, there’s a possibility we may need to have a booster vaccine or something different within the next few years. “That’s too far ahead to even project as we work on the current situation. I think the news, overall, is still good with this situation.”