After months of decline, cases of Covid-19 infection are once again rising around the country. But data shows that the biggest increases are in states that are lagging behind in vaccinations.
Nationwide, the four-week Covid case count has more than doubled as of Monday from the previous four weeks, according to NBC News’ tally. While cases are rising everywhere because of higher transmission levels of the delta variant, the steepest increases have been in the South and Southeast, where Florida, Tennessee, Louisiana, Mississippi and South Carolina are dealing with the biggest outbreaks in the nation.
All five of those states have rates of full vaccinations below the United States’ 49.2 percent, and two of them — Mississippi and Louisiana — are in the bottom five of the entire country.
Health experts say state vaccination rates are the main difference that defines outbreak severity, with Centers for Disease Control and Prevention Director Dr. Rochelle Walensky calling the latest outbreak a “pandemic of the unvaccinated.”
Dr. Brian Strom, chancellor of Rutgers Biomedical and Health Sciences in New Jersey, told NBC News that unvaccinated individuals infected with the delta variant have more than 1,000 times as many viral particles in their respiratory systems as those infected by the original strain.
The available Covid vaccines offer strong protection against becoming severely ill with the delta variant, Strom said, but unvaccinated people are at extreme risk.
“[The delta variant] is dramatically more contagious,” Strom said. “And vaccinations petered out. The net effect is that this would become a disease on the unvaccinated, and that is what happened.”
Missouri, where only 41 percent of the population is fully vaccinated and 47 percent have at least one shot, is dealing with a large increase in cases that is beginning to strain the health care system. Dr. Taylor Nelson, an assistant professor at the University of Missouri’s division of infectious disease, said the university has received more than 20 patients from overburdened hospitals in the state’s southwest corner.
“The spread is just picking up again,” Nelson said. “It's spreading through rural communities where you don't have people packed together like in a city, places that were a bit safer last time.”
A bigger rise in cases could still be on the way, Nelson warned, as Labor Day weekend and back-to-school season will lead to more people gathering indoors. The vaccines are a way to avert further increases, but Nelson said many patients are against getting a shot.
“The main thing and the hardest thing to fight is trying to spread the truth about the vaccines,” Nelson said. “There's so much misinformation out there that a lot of people get those ideas in their heads, and it's really hard to combat that.”
The situation is different in better-vaccinated states like New Jersey, where 58 percent of the population is fully vaccinated and 65 percent have at least one shot. Strom said most new cases in the state are younger unvaccinated people, who tend to have less severe cases. That’s a big difference from spring 2020, Strom said, when most patients were older and very ill.
“The impact on the health care system is much less than it was [last year],” Strom said. “If we didn't have vaccinations, we'd be worse than we were in the beginning of the pandemic.”