The timing of the end of the coronavirus pandemic will depend on the speed of the supply of vaccines to unvaccinated nations, especially in developing countries, as this will help stop a further COVID-19 mutation that could undermine mass vaccination efforts, US experts told.

“The decrease in the number of antibodies worries me less than the population in the United States and around the world that is not vaccinated,” said Edward Trapido, professor of epidemiology and assistant dean for research at the University of Louisiana School of Public Health.

The expert predicts that the pandemic will last until 2022, and then the disease will become more endemic. He noted that this process can be delayed, as “people travel, others escape from war and dangerous situations, and the virus mutates.”

“When variants arise, they can spread quickly and lead to a large number of cases among unvaccinated people. Many populations around the world don’t have or don’t have enough vaccines,” Trapido says.

Efforts to distribute vaccines should focus on Brazil, India, Pakistan, Nepal, South and Central America, and other developing countries, he said.

Dr. Paulo Verardi, a professor of virology and vaccinology at the University of Connecticut, told that countries need to vaccinate at least two-thirds, if not three-quarters or more of their population, to achieve a level of immunity that will disrupt the cycles of transmission and therefore prevent additional waves of the disease.

The expert also noted that new, more contagious variants of the coronavirus “cause concern.” Verardi stressed the importance of working to make vaccines available to people around the world, including in low-income countries because this is the only way to control the pandemic and avoid an increase in the incidence of the disease in the future.