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In Maryland, every person who died of Covid-19 in June was unvaccinated. That's not an aberration, experts say

(CNN) Last month, 130 people died of Covid-19 in Maryland. None of them were vaccinated, according to Maryland Gov. Larry Hogan.

In addition, unvaccinated people made up 95% of new Covid-19 cases in the state and 93% of new Covid-19 hospitalizations, Hogan said at a news conference Wednesday.

The connection between vaccination status and Covid-19 is not specific to Maryland and is not limited to last month, medical experts have said.

Dr. Peter Hotez, dean of the National School of Tropical Medicine at the Baylor College of Medicine, said Maryland's data is a trend that will be seen in states across the country.

"No question that almost all of the deaths and hospitalizations will be in unvaccinated individuals, and therefore we should expect most of severe illnesses, hospitalizations and deaths will occur predominantly in areas of low vaccination and high Delta," such as in the South and Mountain West, he said.

"So far it's confirming what we saw with Phase 3 clinical trials: That all of the vaccines authorized for emergency use give extra protection against hospitalizations and deaths, so this has been confirmed now in very practical settings over the past year," Hotez added. "It's a reminder that you have every reason to get vaccinated."

Maryland National Guard Sgt. Jason Grant administers a Moderna coronavirus vaccine at CASA de Maryland's Wheaton Welcome Center on May 21, 2021 in Wheaton, Maryland.

Dr. Paul Sax, an infectious disease doctor at Brigham and Women's Hospital in Boston, similarly highlighted the Maryland data as evidence of the continued effectiveness of the Covid-19 vaccines.

"We're finding that 99% of the people with severe disease are unvaccinated, so the vaccines are preventing severe disease, even from Delta," he told CNN on Wednesday.

Dr. Rochelle Walensky, director of the US Centers for Disease Control and Prevention, gave similar numbers during a White House briefing last week.

In fact, more than 99% of US Covid-19 deaths in June were among unvaccinated people. In addition, early data suggests that over the last six months, nearly all Covid-19 deaths in a number of states have been in unvaccinated people, Walensky said last week during a White House briefing.

"Preliminary data from a collection of states over the last six months suggest 99.5% of deaths from Covid-19 in these states have occurred in unvaccinated people," Walensky said. She did not specify which states.

In California, just 8,699 out of 20 million fully vaccinated people have become infected with Covid-19 between January 1 and June 30, according to state data. At least 652 of those were hospitalized, and at least 71 died -- a minuscule percentage out of the 37,180 Californians who died in that same time period, according to data from Johns Hopkins.

The data is further evidence of the effectiveness of the Covid-19 vaccines, which have proven to be remarkably effective at preventing on new Covid-19 infections, hospitalizations and deaths, according to studies featuring tens of thousands of people across the world.

The CDC has tracked so-called breakthrough cases in which a vaccinated person is hospitalized or dies from Covid-19. The CDC has tallied 879 deaths among vaccinated people -- a tiny fraction of the more than 600,000 Americans who have died of the novel coronavirus.

Unvaccinated people remain at risk

Overall, new infections, hospitalizations and deaths have sharply declined for everyone over the past few months as over two-thirds of Americans have had at least one vaccine dose.

Yet, unvaccinated people remain susceptible to infection, particularly in pockets of the country where vaccination rates are low.

"It's really sad and tragic that most all of these are avoidable and preventable," Dr. Anthony Fauci, Director of the National Institute of Allergy and Infectious Disease, told NBC's Meet the Press on Sunday.

Fauci noted that no vaccine provides perfect protection for everyone, but the data shows their clear positive impact.

"Obviously there are going to be some people, because of the variability among people and their response to vaccine, that you'll see some who are vaccinated and still get into trouble and get hospitalized and die," he noted. "But the overwhelming proportion of people who get into trouble are the unvaccinated."

Indeed, states with below-average vaccination rates have almost triple the rate of new Covid-19 cases compared to states with above-average vaccination rates, according to data from Johns Hopkins University. In addition, people who have been vaccinated against coronavirus, if they do become infected, have milder illness than unvaccinated people, a CDC study found.

In a news conference Tuesday, President Joe Biden stressed that the vaccines are highly effective and safe.

"Study after study has shown that since early May, virtually every Covid-19 hospitalization and death in the United States has been among the unvaccinated. So, if you're vaccinated, you're protected, but if you're unvaccinated, you're not," he said. "So please get vaccinated now. It works. It's free. It's never been more important."

Infectious disease experts have also explained that unvaccinated people present an opportunity for the virus to mutate.

"The more unvaccinated people are, the more opportunities for the virus to multiply," said Dr. William Schaffner, a professor in the Division of Infectious Diseases at Vanderbilt University Medical Center. "When it does, it mutates, and it could throw off a variant mutation that is even more serious down the road.

"So unvaccinated people are potential variant factories," he added.

CNN's Jason Hoffman, Virginia Langmaid, Lauren Mascarenhas and Naomi Thomas contributed to this report.