Sweden, one of the few European countries to not institute widespread stay-at-home orders to control the coronavirus pandemic, will likely reach herd immunity in its capital and other major regions in a matter of weeks, CNBC reports.

"In major parts of Sweden, around Stockholm, we have reached a plateau [in new cases] and we're already seeing the effect of herd immunity and in a few weeks' time we'll see even more of the effects of that. And in the rest of the country, the situation is stable," the country's chief epidemiologist, Dr. Anders Tegnell of Sweden's Public Health Agency, told the network.

Herd immunity is when 60% of a population is immune to a disease or virus, which is usually achieved through vaccination. Tegnell said that sampling data and models indicate that about 20% of the population in Stockholm, Sweden's capital and the location of most of the country's 15,000 confirmed cases, is already immune to the coronavirus.

Tegnell added, "in a few weeks' time we might reach herd immunity and we believe that is why we're seeing a slow decline in cases, in spite of sampling (testing for the coronavirus) more and more."

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