What are the dangers of unvaccinated children?

On Tuesday, a New York county announced that it had banned unvaccinated children from all public spaces following the largest measles outbreak in the county in decades.

According to the Centres for Disease Control and Prevention (CDC), more than 180 cases of measles have recently been confirmed in New York City.

Officials in Rockland County have emphasised the importance of having children vaccinated, saying that they will "not sit idly by while children in our community are at risk".

So how do vaccines work and what are the dangers of unvaccinated children? Here's everything you need to know:

The aim of vaccines is to help the body produce antibodies that can fight off disease, the NHS explains.

When a person comes into contact with a disease, if they've been vaccinated against it, their immune system should be able to recognise it and produce the antibodies it needs to cause it to dissipate quickly.

Some vaccines are more effective than others.

For example, the MMR vaccine, which protects against measles, mumps and rubella, provides patients with 90 per cent protection against the diseases after one dose.

However, the typhoid vaccine, which individuals get when travelling to countries with high risk of typhoid and hepatitis A, provides around 70 per cent protection for about three years.

Several diseases have been eliminated thanks to vaccines, with some gradually on their way to becoming completely eradicated.

In the 20th century, an estimated 300 million people died from smallpox.

In 1980, it was declared that smallpox had been completely wiped out, with the last known case occurring in Somalia in 1977.

Other conditions on their way to becoming eliminated due to the prevalence of vaccines include polio, whooping cough and meningitis C.

The first main danger of a child not being vaccinated is that they'll be at higher risk of being diagnosed with a harmful disease.

As their body may be unable to produce the antibodies necessary to fight the disease, this could put their life at risk, states Vaxopedia, an online resource created by paediatrician Dr Vincent Iannelli.

However, it's not just their own health that's a cause of concern, but also the wellbeing of others.

If an unvaccinated child catches an illness, they could be at risk of spreading it to someone else who hasn't been vaccinated.

This may include individuals who can't be vaccinated due to health issues, or those too young for the injections.

There is also still a small possibility that those who have been vaccinated can still catch a disease when exposed to it.

Approximately one in seven children around the world do not receive vaccinations that could prove life-saving, charity Save the Children states.

Vaccination currently prevents between two and three million deaths on an annual basis, the World Health Organisation (WHO) outlines.

However, a further 1.5 million deaths could be prevented if vaccination was improved on a global scale, the organisation adds.

Vaccine hesitancy, as described by WHO, is the "reluctance or refusal to vaccinate despite the availability of vaccines".

The organisation explains that the reasons why people choose not to vaccinate are "complex", pinpointing the two main reasons as "complacency" and "lack of confidence".

In January, a report released by the Royal Society for Public Health (RSPH) warned that social media is acting as a "breeding ground" for false and harmful information about the safety of vaccines.

The charity stated that groups looking to spread "misleading and dangerous information" about vaccines tend to be more prominent on social media platforms such as Facebook than in other forms of media.

WHO recently described the anti-vaccine movement as one of the worst threats facing humanity in 2019.

The warning came following a 30 per cent increase in the number of cases of measles worldwide, including in several countries where the disease had almost been completely eradicated.