Outbreak of world’s most infectious disease grows in US… as health officials launch mass vaccinations

Another American state is on red alert after eight new cases of measles have emerged, potentially exposing millions more to the deadly disease.

The patients are located in Spartanburg County in South Carolina and it brings the total number of cases in the state this year to 33. 

The South Carolina Department of Public Health (DPH) reported that all eight new cases were linked to close contacts of known cases who had been quarantining at home. It is unclear if the patients were vaccinated and their ages have not been revealed.

In response to the ongoing measles outbreak across South Carolina, a mobile health unit has been deployed in the region offering measles-mumps-rubella (MMR) vaccines to unvaccinated individuals at no cost.

So far, health officials revealed that it has administered 21 MMR vaccines to 18 adults and children. 

In terms of its vaccination rate, South Carolina is on par with the rest of the country, with the two-dose MMR coverage among kindergarteners at about 92.7 percent. It is, like many states and communities, below the 95 percent threshold.

The uptick of measles cases in South Carolina, which has a population of 5.4 million, comes as the country continues to battle one of its worst measles situations in decades. 

The US has recorded more than 1,618 cases of measles in 2025, more than 60 percent of which are in children and teens, and there have been three deaths with two of these being children.

This far surpasses the 285 cases reported in 2024 and it is the highest annual total since 1992, when there were 2,126 confirmed cases.

About 95 percent of cases have been in unvaccinated people or those who have not completed the recommended two-dose regimen.

Since widespread measles-mumps-rubella (MMR) vaccinations began in 1971, US measles cases had nearly vanished by 2000. 

But infections have now surged to their highest level as vaccination rates slip.

New clusters of measles infections have become increasingly common every year as nationwide vaccination coverage has declined to 91 percent, below the 95 percent threshold needed to achieve population-wide protection.

Outbreaks are particularly common in more insular communities, such as Mennonites in West Texas, the epicenter of an outbreak earlier this year.

In Gaines County, where the outbreak had its genesis, kindergarten vaccination rates were as low as 46 percent in some districts, while rates in some neighboring Lubbock school districts are as low as 77 percent. 

Recent modeling by Stanford University researchers cautioned that, at current vaccination levels and with continuous, uncontrolled spread, the US will lose its measles elimination status within the year.

Measles is among the most infectious diseases on earth. Just one infected person can transmit the virus to an average of 12 to 18 susceptible people, including anyone who has not had two doses of the MMR vaccine, or has not previously contracted measles.

Babies cannot receive the first dose until a year to 15 months and generally get the second when they reach four to six years old, typically right before entering school.

Their protection against measles depends on vaccinated older children creating herd immunity. 

The MMR vaccine is mandatory for school attendance in all 50 states. 

But a growing number of parents are using their states’ exemptions for moral or religious reasons to opt out of mandated vaccines.

This means they can send their children to school unprotected and more likely to spread the virus to a child who cannot be vaccinated for medical reasons or because of age.

In 2014, the exemption rate was about 1.7 percent, before a 2015 measles outbreak at Disneyland drew national attention to falling vaccination rates.

By 2016, exemptions rose to two percent, even as states like California eliminated personal belief exemptions. 

The upward trend continued, hitting 2.5 percent in 2019, the year the US saw its highest measles case count since 1992 before this year’s outbreak, driven by under-vaccinated communities.

The Covid pandemic disrupted vaccination efforts further, pushing exemptions to 2.8 percent in 2021. 

By 2023, rates reached 3.5 percent, with MMR coverage in kindergarteners falling below the 95 percent threshold for herd immunity.

Dr William Schaffner, an infectious disease expert at Vanderbilt University Medical Center, previously told Daily Mail that yearly vaccination declines are ‘sobering.’

‘Vaccine hesitancy and skepticism is alive and well and vaccines,’ he said. 

‘We have considered vaccine hesitancy as a public health and a clinical medicine problem. Of course it is, however, at root, I have come to believe it is an educational problem.’

Many on the anti-vax side cite the now-debunked science put forth in a retracted paper linking vaccines to autism written by Andrew Wakefield, a doctor who has had his medical license revoked.

And the Department of Health and Human Services is currently under the leadership of Robert F Kennedy, Jr, a vaccine skeptic. Since the current outbreak began in West Texas, he has offered mixed messages.

He has said that vaccination is the best way to prevent measles while also casting doubt on whether the children who died really died of measles

Before ever reaching the public, vaccines must clear rigorous clinical trials involving tens of thousands of participants, with ongoing safety monitoring long after approval.

Public health leaders universally agree: immunization remains medicine’s most powerful shield against preventable disease, backed by decades of evidence on safety and efficacy.

HHS provided the following statement to DailyMail.com: ‘HHS continues to support community efforts in dealing with the measles outbreaks. 

‘CDC continues to provide technical assistance, laboratory support, and vaccines as requested. 

‘The risk of measles infection is low for the overall US population, with a case rate of less than 0.4 per 100,000 people, lower than peer developed countries including Canada, the United Kingdom, France, Spain, and Italy. 

‘Measles risk is higher in US communities with low vaccination rates in areas with active measles outbreaks or with close social and/or geographic linkages to areas with active measles outbreaks. 

‘CDC continues to recommend MMR vaccines as the best way to protect against measles. The decision to vaccinate is a personal one. 

‘People should consult with their healthcare provider to understand their options to get inoculated and should be informed about the potential risks and benefits associated with vaccines.’