Measles was eradicated in the US: How did it make a comeback?

Thanks to the introduction of a vaccine in 1963, measles was considered eliminated in the US in 2000. Yet the highly contagious disease has re-emerged as a threat as declining vaccination rates have fuelled outbreaks around the country.

In Texas, an unvaccinated child died on Feb 26 in the first reported US death from the disease in a decade. Other clusters of cases have occurred in recent years, including a large outbreak in New York State in 2019.

In recent years, the virus has ignited outbreaks in the US when infected travellers – both American and international – introduced it into communities with low immunity.

The phenomenon has become more common as the number of Americans who are unvaccinated against childhood illnesses has increased because of persistent and incorrect beliefs that immunisations are dangerous and unnecessary. 

The Texas outbreak

is the worst in the state in three decades. There have been 124 cases and 18 hospitalisations as of Feb 25, and nine cases in neighbouring New Mexico.   

How did measles make a comeback?

Globally, measles deaths dropped sharply from 2000 to 2021 due to vaccination campaigns and rapid outbreak responses.

However, progress stalled in recent years as declining immunisation rates and pandemic-related disruptions fuelled a resurgence.

Since 2020, global measles cases have surged more than threefold, while rubella infections have more than doubled.

Less than three-quarters of children worldwide have received the recommended second dose of the measles-mumps-rubella vaccine, the World Health Organisation (WHO) warned in November 2024.

An immunisation rate of about 95 per cent is needed to prevent community transmission of measles.

Where have the US outbreaks been concentrated?

The virus has spread in rural West Texas and New Mexico, where there are relatively high rates of unvaccinated children. In Texas’ Gaines County, nearly 14 per cent of school-age children skipped a required dose of measles vaccine in 2024. 

How have authorities responded?

Health officials in both states have encouraged residents to stay up to date on measles immunisations.

US Health Secretary Robert Kennedy Jr, a vaccine critic, downplayed the threat, saying during a meeting with President Donald Trump’s Cabinet on Feb 26 that outbreaks in the US were commonplace.

He also suggested that hospitalisations tied to the latest outbreak were “mainly for quarantine”, a claim sharply disputed by a hospital official in West Texas.

Globally, public health authorities fear they will not be able to adequately monitor and respond to the measles threat.

The WHO warned that its largest global laboratory network would collapse unless new funding was secured to replace the support lost after an order by Mr Trump to withdraw the US from the United Nations agency.

How dangerous is measles?

Measles is one of the world’s most contagious viruses, infecting the respiratory tract before spreading throughout the body.

Nine out of 10 unvaccinated people will get the virus if they have interacted with a positive case.

Measles causes fever and a rash, and in severe cases, can lead to complications such as deafness, blindness, pneumonia, and encephalitis – swelling of the brain that can be fatal.

About one in five unvaccinated people infected with measles will require hospitalisation.

In 2024, however, the hospitalisation rate reached 40 per cent in the US, according to the Johns Hopkins Bloomberg School of Public Health.

In 2023, there were an estimated 10.3 million cases worldwide and 107,500 deaths, according to the WHO, mostly among unvaccinated or under-vaccinated children under the age of five. 

Measles is especially dangerous for babies and older people or those with suppressed immune systems, such as cancer patients receiving radiation or chemotherapy.

Measles during pregnancy can lead to miscarriage, early delivery and low birth weight. It can also weaken the immune system for years by attacking B cells, which are crucial for remembering past infections and helping the body fight off diseases.

In rare cases, the infection can linger in the brain, causing a fatal disease years after the initial exposure.

How is measles transmitted?

People can catch measles just by being in the same room where an infected person has breathed, coughed or sneezed within two hours.

An individual can spread the disease unknowingly before showing any signs or symptoms. 

Does measles vaccination cause autism?

No. Some parents might believe that the vaccine causes autism because signs of the developmental disorder typically appear around the same time that children are recommended to receive the first dose of measles vaccine, at roughly one year of age.

But the idea that the vaccine is linked to autism is based on a 1998 study that turned out to be fraudulent.

It was retracted and its author, Mr Andrew Wakefield, was stripped of his UK medical licence for “dishonest” and “irresponsible” work. Repeated studies have debunked any connection between autism and vaccines.

What are the measles vaccine’s actual risks?

The vaccine, which is combined with immunisations against mumps and rubella into a shot called the MMR, is extraordinarily safe.

The vaccine is 93 per cent effective against the virus after one dose and 97 per cent effective after two doses, making it one of the most effective vaccines on the market.

Potential side effects include a sore arm from the shot, fever, mild rash and temporary joint pain and stiffness, mostly among teenage or adult women not already immune to rubella.

The MMR vaccine has been linked with a very small risk (four cases in every 10,000) of seizures caused by a spike in temperature that have no long-term effects.

Serious allergic reactions are extremely rare but have been experienced by patients allergic to the antibiotic neomycin. They should avoid the vaccine, according to the US Centres for Disease Control and Prevention.

What is the treatment for measles?

There is no specific treatment for measles.

Medical care is aimed at addressing symptoms while the virus runs its course, which typically takes seven to 10 days.

Acetaminophen may relieve fever and muscle aches. Rest will boost the immune system. Six to eight cups of water a day will help with hydration. A humidifier can ease a sore throat and cough.

After contracting measles, a person is almost always immune for life. BLOOMBERG