Why the delta variant is causing an explosion of cases among the unvaccinated

Just as millions of people in the United States feel life has returned to normal, the delta variant of the coronavirus became the most prevalent in the country this week, once again raising the stakes in the fight to quell the pandemic.

New data from the Centers for Disease Control and Prevention shows that more than half of all new COVID-19 cases in the United States have been attributed to the delta variant, which is said to be transmitted more easily to others than anyone who preceded him. About a third of Americans are completely unvaccinated and, President Joe Biden said at a press conference Tuesday, vulnerable to the delta variant.

“Our fight against this virus is not over,” Biden said.

In counties where COVID rates are currently the highest, there is a direct correlation with the fact that the vast majority of residents are not vaccinated. More than 99% of people who died from COVID-related causes in June were unvaccinated, Dr Anthony Fauci said on Sunday, and the increase in the delta means “we are seeing an increase in hospitalizations and deaths among unvaccinated people “CDC Director Dr. Rochelle Walensky said Thursday.

Here’s what we know about the delta variant, and why health experts say it’s more important than ever to get the vaccine.

What is different with delta

Since its first identification in October 2020, the delta variant has stood out as the most transmissible known variant of the coronavirus. Without widespread vaccination and without strict adherence to public health measures, such as masking and social distancing, SARS-CoV-2 has been allowed to mutate and evolve over time and will continue to do so.

The data suggests this variant is three times more infectious than the original coronavirus strain, according to Dr Tom Frieden, former director of the CDC who founded Resolve to Save Lives. But it’s still unclear whether this virus is more deadly or leads to more serious illness, said Dr Yvonne Maldonado, head of the pediatric infectious disease division at Stanford University School of Medicine. Some data suggests that the symptoms associated with a delta-variant infection – a runny nose and sore throat – may be slightly different from those at the start of the pandemic. For example, loss of smell is reported less frequently.

The variant devastated India this spring, breaking world records for daily rates of new infections and threatening to collapse parts of that country’s healthcare system. Since then, the World Health Organization has said this variant is on its way to dominating all known infections. And, Frieden added, it shifted the goals from target vaccination rates.

“The collective immunity threshold is higher with delta than before,” Frieden said.

Globally, these efforts “fail” to vaccinate people against the virus and remain “billions” of what is needed to contain the spread of the virus and prevent more mutations and variants, Frieden said. The WHO has set the goal of vaccinating 70% of the world’s population against COVID-19 by next year, but Frieden said current rates are “unacceptable” and millions of people will suffer if more aggressive measures are not taken to speed up vaccination. campaigns.

Some estimates suggest that around 10 percent of the world’s population is currently immune. In most countries, health workers and at-risk populations are still at risk of potential infections, hospitalizations and death from the virus. One scenario that health experts fear is that over time, if transmission continues unhindered in many parts of the world, another variant could emerge that eludes the highly effective vaccines we currently have.

To meet demand, Frieden said companies need to share their intellectual property and technical know-how more widely so more countries around the world can access vaccines, prevent deaths and reduce the spread. virus.

“We have to go a lot faster than what we are doing,” he said.

Risk to the unvaccinated

Vaccine supply is not the problem in the United States Here, 67% of American adults are at least partially vaccinated, which is just short of the Biden administration’s target of having 70% of people aged 18 or over at least partially vaccinated by July 4. a benchmark based on previous estimates of when the United States could achieve collective immunity. Since April 19, the United States has expanded access to vaccines to virtually all adults, later allowing people as young as 12 to get vaccinated. Yet some states with low vaccination rates have returned unused doses to the federal government – an acknowledgment of the surge by public health officials to convince millions of Americans that the coronavirus poses more than an occasional threat.

People forgo vaccination at their own risk, Frieden said.

In the United States, 173 counties have reported high rates of COVID-19 infection of more than 100 cases per 100,000 people, Walensky noted during the White House COVID-19 task force briefing Thursday. In 93 percent of those counties, public health officials say vaccination rates are extremely low – 40 percent or less.

“It’s a very, very dangerous time not to be vaccinated with this circulating variant,” said Dr. Ashish Jha, dean of the Brown School of Public Health.

Hospital staff are running out of ventilators and respiratory therapists in Missouri and in pockets of the country suffering from localized epidemics – conditions the country has already seen at some of the virus’s worst peaks in the past year, before the vaccines are not widely available.

A growing body of data confirms that vaccines, especially Pfizer, Moderna, and Johnson & Johnson, which have been cleared for emergency use in the United States, are widely effective in preventing serious illness and death, even against the delta variant, Fauci said in Thursday’s briefing. Hours later, Pfizer announced that it would ask the FDA to approve a third booster developed to improve immunity against the delta variant. The CDC and the FDA then released a joint statement, saying fully vaccinated people do not need boosters and adding, “We are ready to receive booster doses if and when science shows they are needed. “

Graphic by Megan McGrew and Laura Santhanam / PBS NewsHour

Some adults say they need to be able to take time off work to get vaccinated or recover (something the Biden administration has been working to address through recent tax incentives for employers) and Jha said they will need different policy tools and interventions than those who choose not to be vaccinated for reasons motivated by politics or misinformation about vaccines and the virus.

Those who are dangerously vulnerable to this variant are not limited to those who are not vaccinated by choice or access, but also include those who are not yet old enough to be vaccinated.

Children under 12 should continue to take precautions, such as wearing masks and social distancing, Maldonado said. While communities and households are the main places of transmission, she said children will carry this exhibit with them into the classroom. On Friday, the CDC announced that vaccinated teachers and students could go without masks inside school buildings. Questions were asked about how this policy change could be implemented, including how school administrators could verify the immunization status of students.

And after?

For the weeks and months to come, Frieden warned of a dynamic we are already seeing: “a story of two countries – vaccinated and unvaccinated.” COVID-19 infections will remain low, with occasional increases, in highly vaccinated locations. But in communities where most people aren’t vaccinated, Frieden said, “you’re already seeing much higher rates – five, 10, 20 times higher.” He noted that it is lower “compared to the deadly spring,” but that cases are increasing rapidly.

“What the delta variant does is it shortens the fuse between the start of the spread and the explosive spread,” Frieden said.

“This variation is like tinder sitting in a dry forest” waiting for a spark among the unvaccinated, said Dr. F. Perry Wilson, an epidemiologist who heads the Clinical and Translational Research Accelerator at the Yale School of Medicine.

In this phase of the pandemic, the concept of collective immunity has become hyperlocal, he added. Even though the national numbers look good, it masks how vulnerable some counties remain to devastating epidemics. For people who have been vaccinated but living in areas where most of their neighbors are not, Wilson recommended wearing a face mask when indoors with others.

This can be particularly problematic in rural parts of the country, where the health care system was already on the brink even before the rise of COVID-19. In parts of Missouri or Arkansas, where about a third of people are vaccinated, Wilson said the increased transmissibility of the delta variant, and others that could mutate and rise to take its place, could further overwhelm them. rural hospitals.

Wilson said he doubts a state has the capacity to continue to micromanage epidemics at this level.

“The best choice you can make for yourself is vaccination,” he said.