Scientists say the world has reached a precarious point in the Covid-19 pandemic, where conditions are ripe for the emergence of new coronavirus variants that could complicate efforts to control the disease.
The virus continues to spread rapidly to many parts of the world, even as segments of the population have gained some degree of immunity as a result of being infected or vaccinated.
Scientists say the combination — high rates of viral transmission and a partially immunized population — favors the emergence of potentially more transmissible or more lethal variants. They say more transmission means more opportunities for the virus to evolve.
“If everyone has immunity, you have almost no virus circulating and the virus cannot adapt,” said University of Bern molecular epidemiologist Emma Hodcroft, who added that if no one in a population has immunity, there will be no pressure on the virus. evolve. “This middle part, where you have a partially vaccinated population or a partially immune population with a lot of viruses circulating, is your point of danger,” he said.
The new variants could also reduce the effectiveness of Covid-19 vaccines and treatments and lead to reinfections among people who have already recovered from Covid-19, scientists say. They say the key to minimizing these problems lies in social distancing and other measures to reduce the contagion, as well as in increasing vaccination efforts, which have been left behind in many places.