- CDC data shows 70% of U.S. adults have had at least one shot of a Covid-19 vaccine.
- The milestone is about a month behind President Joe Biden's Fourth of July goal.
- While the milestone is a significant achievement for the nation, it should be seen as a floor, rather than a ceiling, health experts say.
Seventy percent of U.S. adults have had at least one shot of a Covid vaccine, according to data published Monday by the CDC, about a month behind President Joe Biden's Fourth of July goal.
The 70% goal set by Biden in May is seen by federal health officials as a crucial step toward reaching so-called herd immunity — when enough people in a given community have antibodies against a specific disease.
While the milestone is a significant achievement for the nation, it should be seen as a floor, rather than a ceiling, especially as the highly contagious delta variant spreads, health experts say.
"We need to have at least 80% of the population vaccinated to truly have some form of herd immunity," Dr. Paul Offit, a voting member of the Food and Drug Administration's Vaccines and Related Biological Products Advisory Committee, said in a recent interview. "This is a fairly contagious virus."
Dr. Natasha Bhuyan, a family physician with One Medical in Phoenix, said that while the 70% nationwide mark is noteworthy, local communities with lower vaccination rates are still worrisome.
"Even if America reaches 70% or 75%, if we continue to have ZIP codes and neighborhoods at 40 or 50%, they will continue to be at risk of having outbreaks and being hot spots," she said. "Even if we hit the 70% milestone, we can celebrate but we should celebrate it with caution."
The Centers for Disease Control and Prevention's updated data comes almost a week after the agency reversed course on its prior guidance and recommended fully vaccinated Americans who live in areas with high Covid infection rates resume wearing face masks indoors. The guidelines cover about two-thirds of the U.S. population, according to a CNBC analysis.
While the delta variant hits unvaccinated people the hardest, some inoculated people could be carrying higher levels of the virus than previously understood and could transmit it to others, CDC Director Dr. Rochelle Walensky said last week. She added that the variant behaves "uniquely differently from past strains of the virus."
U.S. health officials maintain that the Covid vaccines manufactured by Pfizer-BioNTech, Moderna and Johnson & Johnson are highly protective against the variant, especially against severe disease and death. Still, the pace of vaccinations in the U.S. has slowed in recent months.
The nation is reporting an average of about 660,000 vaccinations per day as of Sunday, according to the CDC, far from peak levels of the more than 3 million daily shots in mid-April but up 14% from one week earlier.
The number of first vaccine doses has climbed more sharply than the overall rate in recent days, representing new people getting their first shots. An average of about 432,000 first doses were reported administered every day over the past seven days as of Sunday, according to the CDC, up 24% from a week earlier. The states with the lowest vaccination rates and worst outbreaks are seeing the biggest increases in first doses, a CNBC analysis found.
Vaccination rates vary widely across the country. Twenty states and the District of Columbia have surpassed the 70% milestone of adults with one shot as of Sunday, CDC data shows, with Vermont, Hawaii, Massachusetts, and Connecticut each across the 80% mark.
Other states lag, and 12 have fewer than 60% of adults with at least one shot. Mississippi, at 50% of adults, has the lowest rate, followed by Wyoming at 52.2% and Louisiana at 53.6%.
In an attempt to boost the number of shots administered, some state and local officials have either offered incentives to getting vaccinated or enforced mandates.
Biden called on state and local officials last week to offer residents $100 cash payments as an incentive to receive a shot, his administration's latest attempt to get more Americans vaccinated.
Biden also called on school districts across the country to host pop-up vaccination clinics in coming weeks, while directing federal pharmacy program partners to work with schools. He also announced that a Covid reimbursement program, which paid back small- and medium-size businesses that offered paid leave for their employees to get vaccinated, would be expanded to include workers' family members and kids, as well.
—CNBC's Kevin Breuninger contributed to this report.