Twenty million children around the world missed out on potentially lifesaving vaccinations last year, Unicef and the World Health Organisation (WHO) have warned.

New data published today shows how progress on vaccinating children against diseases such as measles, diphtheria and tetanus has stalled.

Although more than 100 million children were vaccinated in 2018, rates worldwide still stand at 86 per cent, a long way short of the 95 per cent needed to guarantee protection for the whole population from potentially fatal conditions.

“Vaccines are one of our most important tools for preventing outbreaks and keeping the world safe,” said Dr Tedros Adhanom Ghebreyesus, director-general of WHO.

“While most children today are being vaccinated, far too many are left behind.

“Unacceptably, it’s often those who are most at risk – the poorest, the most marginalised, those touched by conflict or forced from their homes – who are persistently missed.”

The famous faces of the anti-vaccine movement Show all 7 1 /7 The famous faces of the anti-vaccine movement The famous faces of the anti-vaccine movement Charlie Sheen Sheen fought a legal battle against ex-wife Denise Richards to try and block her from vaccinating their children. Richards of course won and Sheen was reportedly so bitter that he paid the paediatrician bill entirely in nickels Getty The famous faces of the anti-vaccine movement Gwyneth Paltrow Paltrow's "health and wellness" company Goop hosted a notorious anti-vaccine speaker at their 2018 Goop Summit Getty The famous faces of the anti-vaccine movement Rob Schneider Schneider demanded the freedom to decline vaccination Getty The famous faces of the anti-vaccine movement Jenny McCarthy McCarthy has claimed that "people are dying from vaccinations", believes that her son caught autism from a vaccine and has pushed her opinions on the topic publicly for many years AFP/Getty The famous faces of the anti-vaccine movement Bill Maher Maher has long spoken against vaccines sating on Larry King live that "a flu shot is the worst thing you can do." His stance appears to stem from a distrust of government AFP/Getty The famous faces of the anti-vaccine movement Alicia Silverstone In Silverstone's book The Kind Mama, she wrote that "there is increasing anecdotal evidence from doctors who have gotten distressed phone calls from parents claiming their child was ‘never the same’ after receiving a vaccine." Getty The famous faces of the anti-vaccine movement Andrew Wakefield Godfather of the anti-vax movement, disgraced doctor Andrew Wakefield famously published a report in the medical journal Lancet claiming a link between the MMR vaccine and autism in 1998. The Lancet retracted the report in 2010 and Wakefield was struck off the medical register PA

Most unvaccinated children live in the developing world, with more than half coming from just 16 countries wracked by conflict and poverty – including Afghanistan, Iraq, South Sudan, Yemen, Syria and Somalia.

Measles, one of the diseases Unicef uses to measure vaccination rates, has seen repeated outbreaks in recent years.

In 2018 more than 350,000 cases were reported, double the 2017 figure. “Measles is a real-time indicator of where we have more work to do to fight preventable diseases,” said Henrietta Fore, Unicef’s executive director.

“Because measles is so contagious, an outbreak points to communities that are missing out on vaccines due to access, costs or, in some places, complacency.

“We have to exhaust every effort to immunise every child.”

Measles outbreaks are not limited to poorer countries, or even those with high vaccination rates overall, Unicef also warned.

Last month, the US saw its highest number of measles cases since 1992, even though the disease – which can in rare cases cause hepatitis, meningitis or even death – was declared eradicated in 2000.

Several of the outbreaks of the disease are connected to Orthodox Jewish communities in New York and Michigan, where anti-vaccine conspiracy theories have become popular.

Several other outbreaks are clustered around the mostly liberal West Coast where unfounded suspicion of vaccination has also become commonplace. Children under five account for half of the cases.

Anti-vaccine misinformation has also spread beyond wealthy, western nations as well.

One Unicef vaccinator in Mali, Dalle Kante, said during a recent measles drive one father refused to have his children vaccinated.

However, once one of them caught measles he “realised that the existence of measles is a reality”, she said. “He then brought all his children to be vaccinated.”

The main factors worldwide which are hindering the spread of vaccination, however, are war and under-investment in national immunisation programmes, Unicef said.

The cost of fully vaccinating a child continues to fall, and in 2017 cost just £14, down from £20 just five years earlier. Every pound spent on immunisations for children produced £44 return on investment for low and middle income countries.