CHICAGO — It was once a simple and largely unquestioned office procedure. Parents took their tots to the doctor to become vaccinated against highly contagious diseases like the measles, mumps, chicken pox and polio.

And families – and the world at large — were better off for it.

Not anymore, apparently.

With everyone from Hollywood celebrities and politicians like Rand Paul perpetuating discredited claims that vaccines increase the risk of autism in children, public anxiety over vaccinations has grown – and so has public resistance.

The new trend has many public health specialists worried – and none more than Leonard Hayflick, the 88-year old biologist at the University of California at San Francisco who first made human vaccines widely available – back in 1962. His development of the normal human cell strain was paramount in the production of vaccines against more than 10 diseases.

Hayflick recently published a study with a colleague at the University of Illinois at Chicago (UIC) to document the millions of lives saved by his pioneering work over a half century ago.

“Given the acknowledged large, positive global health impact of vaccines in general, I was curious what contribution my discovery….had in saving lives and reducing morbidity, since a large number of viral vaccines in use today are made with my cell strain or its derivatives,” Hayflick says in a UIC news release.

At Hayflick’s behest, S. Jay Olshansky, professor of epidemiology in the UIC School of Public Health, reviewed the prevalence and morbidity rates for 10 common viruses in 1960 prior to the development of effective vaccines. He then estimated the number of virus cases that would have developed and the deaths that would have occurred if vaccines had not become available.

According to Olshansky’s calculations, thanks to vaccines, 4.5 billion virus cases were averted and 10.3 million lives saved worldwide – including 2.7 billion and 6.2 million, respectively, in Asia alone. In the United States, about 200 million cases were averted and 450,000 lives saved.

Hayflick’s hoping the sheer weight of the historical evidence might help soothe the public’s growing anxiety.

But to date pro-vaccine public health campaigns have not had much impact – in fact, there’s evidence they’ve actually backfired. A study published in the journal Pediatrics in 2014 found that parents previously unaware of the autism vaccination controversy were becoming more anxious due to the publicity and were less likely to get their children vaccinated.

Opposition to vaccination has already been blamed for a major multi-state outbreak in Anaheim, California in early 2015. And vaccination rates for some of the most dangerous childhood diseases, including whooping cough, may be falling to dangerous levels, studies show.

“If the anti-vaccination movement gains any additional traction, developed and developing nations will have taken a dangerous step backward in protecting public health, especially of children,” Hayflick says.

“There is no medication, lifestyle change, public health innovation, or medical procedure ever developed that has even come close to the life-saving, life-extending, and primary prevention benefits associated with vaccines,” he adds.

Olshansky’s research was supported by a grant from the MacArthur Foundation. The study is published in AIMS Public Health.