Two cases of infection with the South African strain of coronavirus have been registered in Croatia, Public Health Institute epidemiologist Goranka Petrović told N1 television on Saturday.

“Yesterday we received the sequencing results for the samples we sent to the European Centre for Disease Control. Of the 300 samples whose results arrived, 60 were positive for the British strain, which was 20% of the positive samples. That's a quite high percentage. The South African variant was confirmed in two persons who returned from Africa, from Zanzibar,” Petrović said.

According to existing data, she added, the British variant is spreading faster, “up to 50%.”

She said the British variant was not confirmed to avoid the immunological response, “which is the case with the South African variant.”

According to her, some South African variant mutations increase the likelihood of avoiding the immunological response, including by partly or significantly reducing vaccine efficacy or by making those who recovered from COVID-19 liable for reinfection.

Petrović said vaccine manufacturers were closely following the new variants.

“Research has shown that both the Pfizer and Moderna vaccines, and especially AstraZeneca's, have weaker efficacy against the South African variant, and they are thinking of ways to modify their vaccines,” she said, adding that the adjustment “should be relatively easy.”