The head of the World Health Organization (WHO) on Wednesday warned that unless the situation drastically changes for the better, the world will pass 300 million COVID-19 cases by early next year.
WHO Director-General Tedros Adhanom Ghebreyesus said the number of recorded COVID-19 infections surpassed 200 million last week, just six months after passing 100 million. He added that the numbers are almost certainly an undercount.
"At the current trajectory, we could pass 300 million reported cases early next year, but we can change that," Tedros said. "We’re all in this together, but the world is not acting like it."
Tedros noted that while there are no vaccines for Marburg, a deadly hemorrhagic fever similar to Ebola that was recently confirmed in a patient from West Africa, "we have several effective vaccines for COVID-19, and yet cases and deaths continue to rise."
WHO officials during a media briefing also addressed concerns about how the delta variant will impact herd immunity.
Katherine O'Brien, director of the WHO's immunization department, said there is no "magic number" that needs to be achieved.
"It is really related to how transmissible the virus is," she said.
Measles, for example, would need about 95 percent of the population immune or vaccinated because it is so contagious.
"What’s been happening with coronavirus … is that as variants are emerging and are more transmissible. It does mean that a higher fraction of people need to be vaccinated in order to likely achieve some level of herd immunity," O’Brien said.
"This is an area of scientific uncertainty," she said, so the studies that evaluate the degree to which the vaccines protect against transmission are important.
U.S. health officials have been trying to disabuse the public for months of the notion that there is a "herd immunity" target. Instead, they've been focusing the message on getting as many people vaccinated as quickly as possible.