Gail Adams Batt, one of the children who received the experimental polio vaccine in 1954, looks at her first-grade school portrait at her home in Arlington. (Kate Patterson/For The Washington Post)

Jackie French Lonergan was a second-grader at Franklin Sherman Elementary on April 26, 1954, when her family doctor, Richard Mulvaney, made history with the push of a syringe plunger.

“We were called polio pioneers,” said Lonergan, 68, who was among the first children in the United States to receive the vaccine formulated by Jonas Salk to prevent poliomyelitis. At the time, the virus was afflicting tens of thousands of children each year, causing paralysis and sometimes death.

“It was nice to know that I was part of that leading edge,” said Lonergan, who lives in Carmichael, Calif. “I did know people who had withered legs and had to use braces and things to walk.”

Six decades ago, Lonergan’s elementary school, in McLean, Va., was thrust into the vanguard of a national campaign to eradicate polio, a campaign that answered the pleas of Fairfax County parents — of parents almost everywhere — for a way to protect their children from the disease.

Mulvaney emerged as one of the campaign’s heroes, clad in a white lab coat and armed with sterile needles and lollipops for the first subjects in what became the largest medical experiment in history. In all, nearly 1.4 million American children participated in the trial. Sixty years ago this month, the vaccine was declared safe and effective after nearly a year of evaluation.

Dr. Jonas Salk administers a trial polio vaccine to David Rosenbloom of Pittsburgh in this 1954 photo from the National Foundation March of Dimes. (Associated Press)

On April 12, 1955, the nation rejoiced at the news. Church bells rang. Car horns honked. People wept in the streets. At a hastily arranged White House ceremony, President Dwight D. Eisenhower became emotional as he honored Salk. “I have no words to thank you,” the president said.

In the 1940s and 1950s, about 35,000 people a year were debilitated by polio. At its peak, in 1952, more than 60,000 cases were reported in the United States, resulting in 3,000 deaths, according to the 2005 book “The Death of a Disease: A History of the Eradication of Poliomyelitis.”

Polio cases are now rare, with 359 cases reported worldwide in 2014, according to the Centers for Disease Control and Prevention, but there are worrisome pockets of polio.

Vaccines are now available for many common diseases, such as measles and rubella. The vast majority of children today undergo a routine battery of inoculations before kindergarten against ailments that previously ran rampant in classrooms. But vaccination — two generations ago heralded as a savior — is increasingly a matter of public debate. Some parents refuse to have their children vaccinated because of skepticism about the safety of vaccines, and experts say that has led to recent outbreaks of measles and whooping cough.

“People in the current generation don’t remember that there were plenty of people who died from measles,” said Peter L. Salk, son of the polio vaccine’s discoverer and vice president and scientific director of the Jonas Salk Foundation.

One of the country’s staunchest critics of vaccines, Barbara Loe Fisher, was among those children who decades ago received the polio vaccine at her parents’ behest. Her father had survived a bout of polio, and his right leg was permanently weakened.

Richard Mulvaney, a McLean, Va., family doctor, injects the polio vaccine into the arm of 6-year-old Randall Kerr on April 26, 1954. (Associated Press)

“We were taken into the auditorium and vaccinated. That’s just what was done,” Fisher said, noting that her mother was a nurse. “I know that my mom did what she thought was right.”

Fisher said she believes that it is up to parents to decide whether they want their children to be inoculated, and she began speaking out against vaccination after her 2-year-old son had an adverse reaction to a DPT shot, intended to protect children from diphtheria, pertussis and tetanus.

“Everybody who looks at this issue has got personal experiences,” Fisher said. “It certainly is true that the parents back then were wanting a vaccine that would protect their children.”

In the middle of the 20th century, polio was the most feared disease in the United States. It preyed on the young, killing some children and leaving others incapacitated in iron lungs.

At the time, little was known about polio, other than that the disease came with the warm weather in the spring and summer, breaking out in small towns and major cities. It could afflict anyone, including, perhaps most famously, Franklin D. Roosevelt, the future president, who contracted the disease at 39 in 1921.

When polio appeared, it could shutter an entire community, David M. Oshinsky wrote in his Pulitzer Prize-winning history “Polio: An American Story.” He wrote that after the disease struck a Texas town in 1949, the municipal pool, bowling alleys, bars and churches closed their doors.

So when Salk’s vaccine was ready for trials, the nation mobilized. Funded by tens of millions of private dollars raised through its March of Dimes campaign, the National Foundation for Infantile Paralysis organized 14,000 school principals, 50,000 classroom teachers, 20,000 physicians and 40,000 nurses, according to Oshinsky’s book.

Although it had shown promise in relatively small tests, Salk’s vaccine was not without risks. The popular and influential radio broadcaster Walter Winchell took to the airwaves to warn parents about the shots. As a result, doctors in the District canceled a first round of inoculations amid expressions of concern by wary parents.

Then Mulvaney stepped in, volunteering to be the first to administer the inoculations — to children at Franklin Sherman, a school near his office in McLean.

Gail Adams Batt was a second-grader at Chesterbrook Elementary, two miles from Franklin Sherman, when the proposal to vaccinate came up at a PTA meeting. Her mother, Marjorie Adams, was aware of parents’ concerns about the vaccine’s safety.

“She was sitting in there, and they needed a few children for the trial, and absolutely no one was raising their hand,” Batt said. So her mother did, and Batt became one of the first children to receive the vaccine.

“When I was an adult, I asked her why’d she do that,” Batt said. “She said, ‘I wanted to do something that would make Eleanor Roosevelt proud of me.’ ”

Batt remembers the day she got the shot at Franklin Sherman and the ice cream sundae that was her reward. She also remembers that being selected to be vaccinated meant that maybe she would be one of the lucky ones. Batt said she never forgot the boy who sat behind her in class who didn’t show up for school one day after he was stricken with polio.

“We used to go and stand outside his house and look up and wonder where he was or how he was,” Batt said. “His desk sat empty from then on.”

Other parents were eager to accept a calculated risk in return for a chance to stave off the disease.

The Washington Post carried news of the first waves of vaccinations on the front page on April 27, 1954:

“The nation yesterday unsheathed its newest weapon against the vaunted crippler polio and the first battleground was the body of a gritty 6 year old Falls Church boy.”

That child was Randy Kerr, who like Batt and Lonergan, lined up at Franklin Sherman for the first round of shots.

Mulvaney had been Lonergan’s family doctor, and a picture of her being vaccinated appeared on a March of Dimes poster.

Mulvaney had served at a forward base in Korea, attending to wounded combat troops, which steeled his nerves after critics openly questioned the vaccine’s potential, said his son, John Mulvaney. The doctor trusted the research behind the vaccine enough to administer it to his children days after it became available.

“No kid likes shots, but we understood from him that it was perfectly safe and that we were getting it whether we wanted to or not,” John Mulvaney said.

Batt credited her mother’s generation with having the courage to let their children receive the unproven vaccine.

“I started thinking, ‘Would I have volunteered my daughter on some clinical trial like this?’ ” Batt said. “I don’t know that I would have.”

Batt said she cringes when she hears of parents who do not have their children vaccinated, especially in light of the experience of families who scrambled in the 1950s to have their kids inoculated against polio.

“It was a different era,” Batt said.

Today, Americans remain overwhelmingly supportive of vaccination. According to the latest figures from the CDC, 91.9 percent of U.S. children are vaccinated for measles, mumps and rubella, and 92.7 percent are immunized against polio.

Kerry Sheehan, Mulvaney’s granddaughter, said she was inspired by his work to pursue a career as a pediatrician.

“He really followed what he felt was right and what he knew would be good for the world,” Sheehan said. “I have seen almost every illness we vaccinate against except for polio. He was always sort of astounded by that. It was so prevalent and so much on his mind as a young physician. He never thought in his lifetime it would be eradicated.”