As promised, there are now plenty of COVID-19 vaccines available in the U.S. for people who want them. But not everyone is taking what's being offered.
Some states have started to decline their full allotment of vaccine shipments from the federal government due to a drop in demand from residents. Recently released data from the Centers for Disease Control and Prevention found that 8 percent of people who had one dose of an mRNA vaccine through April 9 didn't receive their second shot during the scheduled window. That’s about 5 million people who may have missed their second dose.
The CDC also found the rate of people who are not getting their second dose more than doubled from the 3.4 percent reported in February. (The CDC did say, though, that this was to be expected as more people became eligible for the vaccine.)
Cases of COVID-19 in the U.S. have started to drop again after a jump following spring break, according to CDC data, but they're still on par with levels the country saw in July.
This vaccine news raises questions about what will happen next as the U.S. enters a new phase of the pandemic and whether herd immunity is even possible.
"It's going to take longer to get there," infectious disease expert Dr. Amesh A. Adalja, senior scholar at the Johns Hopkins Center for Health Security, tells Yahoo Life. "Herd immunity is an important threshold, but it's not the only one," he says.
Adalja points to data from Israel, which started to see a big drop in COVID-19 cases when about 40 percent of the population was fully vaccinated. (Currently, CDC data shows that 28.5 percent of the population was fully vaccinated against COVID-19, and 36.5 percent of the population over the age of 18 has received the full course of the vaccine.)
"We've already seen benefits in terms of hospitalizations and, largely, concerns about hospital capacity," Adalja says. "But we'll have much better control when we can get to at least 40 percent."
Dr. John Sellick, an infectious disease expert and professor of medicine at the University at Buffalo/SUNY, tells Yahoo Life that it's "unfortunate" more people haven't been fully vaccinated. "We're always concerned about the usual pandemic fatigue but now as the weather is getting nice, people are starting to say that the pandemic is over or that they just don't care anymore," he says. "We don't know what the magic number is to reach herd immunity, but it's certainly more than what it is right now. We've got a ways to go, no matter what."
There could be a few reasons more people aren't fully vaccinated at this point, Dr. William Schaffner, an infectious disease specialist and professor at the Vanderbilt University School of Medicine, tells Yahoo Life. "Some are concerned about side effects, others are too busy, and some have probably heard that protection is good with the first dose — so why bother with the second?" he says. But Schaffner points out that just getting one dose of an mRNA won't get people near the almost 95 percent protection that the Pfizer and Moderna vaccines can offer. "The second dose really does boost your antibodies," he says. "It extends protection for a longer period of time too. Both of these factors are very important."
What does this mean going forward? Adalja says it's highly unlikely that states will bring back restrictions: "I think we're done with that," he says. But Sellick says that people not getting their full course of vaccination or even a first dose "certainly does raise the possibility that we could see another wave of infections," especially going into the fall when people are indoors more.
Experts stress that more Americans getting the vaccines is necessary to get life back to normal. "The more people who get vaccinated, the quicker this will be over," Dr. Martin J. Blaser, professor of medicine and pathology and laboratory medicine at the Rutgers Robert Wood Johnson Medical School, tells Yahoo Life. "The fact that people aren't going to be fully vaccinated is bad news for society in general, but it's especially bad for the people who aren't being vaccinated. This vaccine is lifesaving. I can't stress that enough."
Schaffner urges people to get the full course of vaccination. "We would like you to be optimally protected, particularly against the variants, for a longer period of time," he says. "Long protection is better protection. Get that second dose. Make the effort."
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