CNN  — 

As US officials push for more vaccinations amid slowing demand across the country, another state has now crossed an important milestone.

Rhode Island is now the eighth state to have administered at least one Covid-19 shot to 70% of its adult population, according to data from the Centers for Disease Control and Prevention.

The state joins Connecticut, Hawaii, Maine, Massachusetts, New Hampshire, New Jersey and Vermont, which have also vaccinated at least 70% of their adult population.

Twenty five states and Washington, DC, have now fully vaccinated at least half of their adult populations.

The news builds on experts’ optimism about the country’s declining Covid-19 case numbers and where things could stand by summer time as vaccine numbers continue to climb. Earlier this month, President Joe Biden set a goal of administering at least one Covid-19 vaccine dose to 70% of American adults by July 4 – and has said Americans will be able to celebrate Independence Day by then with a true semblance of normalcy.

So far, more than 61% of US adults have gotten at least one Covid-19 shot and more than 49% are fully vaccinated, according to CDC data.

And about 49% of the total US population, including children over the age of 12, has received at least one shot and 39.2 % of the population – about 130 million people – is fully vaccinated, that data shows.

But the demand for a shot is down – and experts worry the slowing vaccinations may mean some communities don’t reach the widespread protection levels that officials hope for and continue to face outbreaks.

“I think we’ll be dealing with Covid-19 for quite a long time unfortunately,” emergency room physician Dr. Rob Davidson told CNN on Saturday, when asked what could happen if the country doesn’t vaccinate enough of the population.

According to CDC data published on Thursday, the average daily pace of Covid-19 vaccinations was down almost 50% from its April peak.

“We just have to keep pushing forward because, thinking about what could happen if we don’t get there, I just think we have to keep using every resource we have to get more people vaccinated,” Davidson said.

A photo of Covid-19 vaccinations in Central Falls, Rhode Island, on February 13, 2021

The barriers to vaccines that persist

There are still several challenges officials are working to overcome in the country’s vaccination efforts.

Experts say many Americans still have questions about the vaccines, haven’t received enough – or the right – information and others have problems with access, including being unable to take off of work to go get a shot.

“Employers not only have an opportunity to increase vaccination rates but… it turns out that they can also help to close the equity gap in vaccinations,” US Surgeon General Dr. Vivek Murthy said during a White House Covid-19 briefing on Friday.

“This is so important because we’ve said from the beginning that success is not just determined by how many people we get vaccinated but by how equitably and fairly we vaccinate our population,” he added. “And workplaces, it turns out, can play a role in that.”

CDC Director Dr. Rochelle Walensky also said last week the agency was asking businesses to support their employees to get vaccinated.

“We are really asking the businesses to work with their workers to make sure that they have the paid time off to get themselves vaccinated so they can be safe,” she told CNN last Sunday.

The next phase of the country’s vaccination is an “all-hands-on-deck” approach, Murthy said Friday – driven by communities themselves.

“Please reach out to your family and friends,” he said. “Remind people the vaccine is free of charge. It’s now easier to get than ever before. And remind people also that the vaccine remains our single best pathway out of the Covid-19 pandemic.”

Track Covid-19 vaccinations in the US

It’s OK if you’re not ready to take off your mask

The ongoing vaccine push also comes as parts of the US are still navigating the recent CDC guidance, which said fully vaccinated Americans can – for the most part – ditch their masks and don’t have to practice social distancing. The guidelines triggered a wave of policy changes across the country, from both state leaders and businesses.

But some vaccinated Americans say despite the new guidance, they don’t feel ready to shed their face masks and go back to crowds.

And that’s okay, Dr. Anthony Fauci said Friday.

“Fears like that are not irrational,” Fauci said during the White House Covid-19 briefing. “You can understand that when people have been following a certain trend for a considerable period of time, that it may take time for them to adjust. So I would not say that that’s irrational, I’d say that’s understandable.”

Walensky, with the CDC, has also previously said that fully vaccinated immuno-compromised people – who may still face a higher risk – should consult with their doctor before deciding whether to stop wearing a mask.

As more Americans get vaccinated, it will become “progressively more safe” to be out and about again, Dr. William Schaffner, an infectious diseases professor at Vanderbilt University, told CNN on Saturday.

“If we’re vaccinated, that vaccine is going to provide us very, very good protection,” he said. “But we need these other people to come in and be vaccinated also.”

And that will also help address concerns about whether to mask up or not, Schaffner added.

“We’ll solve this problem, we don’t have to worry about who’s wearing a mask or not, if we’re all vaccinated,” he said.

Vaccine incentive programs appear to work

To help get more shots into arms, some state leaders have rolled out specific incentives for their residents, including road maps to normalcy and cash.

Vermont Gov. Phil Scott said Friday the state will remove all remaining Covid-19 restrictions when 80% of the state’s eligible population has received at least one Covid-19 shot.

“If you are on the fence, or have not gotten around to making your appointment yet, now is the time,” Scott said. “Because we have a chance to get back to normal faster and it has never been easier to get vaccinated.”

Other governors have announced lotteries – and those programs appear to be working, White House senior Covid-19 adviser Andy Slavitt said Friday.

“I think the reason they work is because the vast number of people who are not yet vaccinated are actually not opposed to getting vaccinated, they’re just not prioritizing it very high,” Slavitt said. “So things that draw attention to it, like the lotteries… are – not surprisingly – very effective.”

New York Gov. Andrew Cuomo announced adults who get vaccinated in certain mass vaccination sites this week will be given a lottery ticket with a chance to win as much as $5 million. Maryland Gov. Larry Hogan said starting Tuesday, the state lottery will randomly select a vaccinated resident for a $40,000 prize every single day – and those drawings will continue for 40 days. On July 4, a final drawing will be held to award a vaccinated Marylander a grand prize of $400,000, Hogan said.

In Ohio, where the governor recently announced a weekly drawing for vaccinated residents, health officials said last week the cash incentive is making a difference.

Since its May 13 announcement, the campaign “helped drive an increase in vaccination rates among Ohioans 16 and older by more than 28 percent,” Ohio’s health department said in a news release.

Prior to the announcement, vaccinations in residents 16 and older had seen a decrease, the department said.

CNN’s Virginia Langmaid, Rebekah Riess, Melissa Alonso and Deidre McPhillips contributed to this report.