Anti-vaccination campaigners are preparing to release the sequel to Vaxxed, the highly contentious film that has been used to spread the unfounded claim that vaccines cause autism and other developmental problems.

Vaxxed II: The People’s Truth will be premiered on 6 November in 50 venues across America. Its producers, led by Robert F Kennedy Jr, are keeping locations secret with tickets sold quietly in advance in the hope of foiling efforts to block the movie.

From 7 November, the film will be taken on the road in the same “Vaxxed” bus that was deployed in 2016 to disseminate the original film, traveling more than 50,000 miles from coast to coast of the US. The movie was a powerful propaganda tool for the anti-vaccination movement, which has seen a surge in recent years within certain religious communities and among parents worried about scientifically unproven so-called “vaccine injuries”.

Vaxxed II lands at a particularly anxious time in the US, where several states including California and Washington have been battling against localised outbreaks of measles. The worst affected state, New York, only recently succeeded in bringing the disease under control.

Official figures compiled by the Centers for Disease Control and Prevention (CDC) show that in the first nine months of this year some 1,249 measles cases were reported in the US – the largest incidence of the disease in almost 30 years. Of those, one in 10 were hospitalized.

The explosion of cases of an illness once considered eliminated from the US has alarmed medical experts. They predict children will die unless anti-vaccination fears among parents are assuaged.

“If that level rises to 2,000 or 3,000 cases a year we will start to see children dying of measles once again. That’s the dangerous game that is being played here,” said Dr Paul Offit, a vaccine expert at the Children’s Hospital of Philadelphia.

Running to 92 minutes, Vaxxed II bears many of the hallmarks of the original Vaxxed movie. The film, which the Guardian has previewed, is slickly produced and carries considerable dramatic punch – making its message all the more potent.

Publicity for the film carries the tagline: “The film they can’t let you see”. The slogan is a reference to moves to restrict access to Vaxxed in the wake of public outcry against the spread of anti-vaxxer conspiracy theories. In March, Amazon decided to remove Vaxxed from its streaming service following protest by the Democratic congressman Adam Schiff. Similar moves have been made by social media sites, although NBC News last month found that money was still being raised for the Vaxxed bus through crowdfunding on Facebook.

When the original Vaxxed movie was released in 2016 it become the center of a public firestorm after Robert De Niro booked it for his Tribeca film festival, then pulled it following objections from doctors and scientists. The film’s producers claim the ensuing furore was the best thing that ever happened to the anti-vaccination movement as it drew attention to the cause and attracted hundreds of people to the Vaxxed bus.

Those individuals, who were filmed recounting their experiences on the bus, now form the core of Vaxxed II. The film makes no effort to address the scientific evidence that the parents’ experiences of autism in their children have nothing to do with vaccines, or the coincidence that symptoms of autism often appear between 12 and 24 months of age, exactly when the measles, mumps and rubella (MMR) vaccine is given.

In the absence of such context, the stories told on the bus and aired in Vaxxed II are heartbreaking, harrowing and deeply unnerving. The families’ narratives are accompanied by disturbing footage of non-verbal autistic children. There is a gallery of photographs of babies who died before their second birthdays – the film claims without offering any evidence that their deaths were caused by vaccines.

In a later section of the film, parents who have decided not to vaccinate their children speak to camera. They relate how their kids have never had a day’s illness or needed a course of antibiotics, and the film-makers imply they are also more intelligent than their vaccinated neighbors’ children.

Robert F Kennedy Jr, who is credited as an executive producer of Vaxxed 2, said the aim of the film was to give “vaccine-injured” individuals and their families a voice.

“Their stories are muzzled by the media, and the film in many ways is an effort to allow those families a chance to speak,” he said in an interview with the Guardian.

Kennedy is a son of Robert F Kennedy, the Democratic leader who was assassinated in 1968, and nephew of John F Kennedy. An acclaimed environmentalist who pioneered campaigns to clean up rivers, Kennedy has in recent years channeled his energies through his organization Children’s Health Defense into the anti-vaccination movement.

“I’m not anti-vax,” he insisted. “I am somebody who is skeptical of government and pharma, but I’m not anti-vax.”

Kennedy cited his father, a legendary figure among Democrats, as rationale for his hostility towards vaccines. “My dad told me when I was a little kid, people in power lie and if you want to live in a democracy you have to treat every government pronouncement with skepticism,” he said.

Kennedy described himself as being devoted to scientific truth. Yet many of the claims he makes in Vaxxed II and repeated to the Guardian have been thoroughly disproved over many years. His main allegation that vaccines cause autism has been conclusively countered by 18 studies conducted in seven countries across three continents involving hundreds of thousands of children.

In his Guardian interview, Kennedy said that the current measles outbreaks occurred mainly among patients who had been vaccinated. “Seventy-nine percent of the cases in California this year were in adults where the vaccine had failed.”

In fact, the California department of public health has reviewed the 39 measles cases in the state this year where the vaccination status of the patients was known and found that 69% were partially or wholly unvaccinated. Nationally, CDC has recorded that 89% of measles patients this year were unvaccinated or had an unknown status – only 11% had received MMR.

The other character who appears prominently in Vaxxed II is Andrew Wakefield, the disgraced British former physician who was the first to generate public doubts about MMR. In 1998 Wakefield published a paper in the Lancet based on the histories of a mere eight children that put fear into the hearts of many parents by suggesting a possible link between MMR and autism.

The ripple effect of Wakefield’s study was a dramatic slump in vaccine uptake in the UK and US.

In 2010 the UK’s General Medical Council stripped Wakefield of his license to practice as a doctor on grounds of “dishonesty” in his vaccine work as well as multiple ethical breaches in the way he enlisted children to the study. Wakefield’s Lancet article was retracted a few months later.

Despite having been shunned by the British medical world, Wakefield has rebuilt his life in America as a celebrity figure revered by vaccine skeptics. He directed the first Vaxxed film and appears in Vaxxed II as an authority on the spurious science of “vaccine injuries”.

In the movie, Wakefield presents himself as uncowed and unashamed, David standing up to the Goliath of big pharma. “It can change and it will change, and we will win this battle,” he says.

He argues for a return to the days of herd immunity, in which almost all children got measles by the age of 15. “Herd immunity worked extremely well – exposure to measles protected you,” Wakefield says.

What he does not say was that until the measles vaccine was created in 1963, up to 4 million Americans contracted the illness each year. Of those, 48,000 were hospitalized and 1,000 suffered encephalitis – swelling of the brain.

Some 500 people, many of them children, were recorded to have died from the disease.

For a vaccine scientist like Offit, the idea of returning to the days of herd immunity is horrifying. “The public is sick and tired of the anti-vaccine movement,” he said. “Children are being admitted to intensive care units with severe measles and pneumonia – a clear line in the sand has been crossed.”