On Monday, Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention (CDC), warned that the seven-day average of COVID-19 cases reached 67,440 cases a day. This was a significant increase from a month ago – when, as Walensky noted, the seven-day average was “just over 53,000 a day.
“Unfortunately, the seven-day average of daily deaths is now rising, with six consecutive days of growth, to about 695 deaths a day,” Walensky said.
The slow rise in COVID-19 cases across the country may seem inconsistent with another basic public health fact: in the same time, tens of millions of Americans have been completely vaccinated against the new coronavirus, which causes COVID-19. According to the CDC, more than 50 percent of American adults over the age of 18 in the United States have received at least the first dose of vaccine; almost 25% of the population is completely vaccinated. As Walensky noted Monday, that means more than 84 million are fully vaccinated; and of those vaccinated, the United States had fewer than 6,000 “revolutionary infections” in which fully vaccinated people tested positive for COVID-19.
Given the rapid launch of vaccinations, the news of the increase in cases may seem very strange. Indeed, shouldn’t cases start to go down as more people get vaccinated?
Dr Amesh Adalja, a senior scientist at the Johns Hopkins Center, said the reasons for this were related to demographics – in particular, who was vaccinated and who was not.
“If you look at the demographic data of the cases that occur, they are often in that age group between the 20s and 30s, which has not been largely vaccinated,” Adalja said. “I think it will take some time for the cases to go down as the vaccine gets into that population.”
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Indeed, up to this week, availability in all states has been based primarily on age groups; COVID-19 vaccines are only now available for people in their 20s and 30s. And indeed, younger adults seem to be infected. Last week, Conway Daily Sun of New Hampshire reported that young people accounted for nearly half of the state’s new COVID-19 cases. It is also believed that young people are growing up in states like Michigan, where young people are hospitalized.
Adalja said he believes the US will see cases decline when more people are vaccinated – maybe around 40%, which he says could be a turning point.
“All you have to do is look at a country like Israel, where they managed to vaccinate a huge proportion of their population, and once they reached about 40%, you started to see the cases fall,” Adalja said. It is difficult to know exactly when we will cross this threshold, as the threshold will be crossed by a combination of natural infection and vaccine-induced immunity.
Adalja mentioned that “one of the biggest obstacles now will be the hesitation of the vaccine”.
According to a survey conducted by Axios-Ipsos last week, 30% of those surveyed said they were “not at all likely” or “very unlikely” to get vaccinated when possible. 20 percent of respondents said “I will not receive the vaccine” after the vaccine becomes available to them.
Monica Gandhi, a doctor of infectious diseases and a professor of medicine at the University of California – San Francisco, told Salon that it is difficult to make comprehensive generalizations about this trend across the country because of the way the pandemic varies across the country. “It’s like almost 50 different pandemics across the country,” Gandhi meditated.
Gandhi noted that 50% of new cases come from several states: Minnesota, Michigan, New York, Florida and Pennsylvania. One metric that Gandhi follows is what he refers to as the “hospitalization rate per case,” which tracks the number of cases leading to hospitalizations.
“They are starting to erupt and what I mean by delink is that the same number of cases does not lead to the same number of hospitalizations that we had before,” said Gandhi. “I think it’s about vaccinating the elderly first.” In other words, fewer cases of COVID-19 lead to hospitalization, which is a good sign.
Gandhi said, however, that a large number of infected young people will lead to an increase in hospitalizations. Gandhi also pointed to Israel as an example of how the US could wait to reach a turning point.
The spread of highly transmissible variants could play a role in increasing the number of cases across the country, but Gandhi said that’s probably not the only reason. The COVID-19 strain known in B.1.1.7., Which was first identified in the United Kingdom, is thought to be 40 to 70 percent more transmissible.
“I am sure that in the places where B.1.1.7 circulates and this was also true in Israel, it seems to have an increased transmissibility and I am sure that it contributes,” Gandhi said. “However, this cannot be the only reason, because there are places that have equally high percentages of variants and do not have overvoltages.”
Gandhi said another contributing factor to growth in the United States could be the tendency of people to gather, along with the degree of natural immunity of a state’s population. However, she said she hoped it could get closer to the “turning point” where cases began to decline nationwide.
“I think we are very, very close,” Gandhi said.