The outbreak, like those in other regions, has been fuelled by a rise in vaccine hesitancy since the Covid-19 pandemic, leaving many US communities vulnerable to outbreaks of measles and other vaccine-preventable diseases.
The number of measles, mumps and rubella (MMR) vaccine doses administered in Spartanburg County, near the North Carolina border and the epicenter of the latest outbreak, has increased 102% over the past four months compared with the same period a year earlier, according to state data shared with Reuters. More than 1,000 additional shots were delivered in January.
Statewide, MMR immunisations were up 28% during the same four-month period.
“These monthly totals are some of the highest we’ve seen in years,” Dr Linda Bell, South Carolina’s state epidemiologist, said in emailed comments to Reuters.
She said 1,178 doses of MMR vaccines were given to infants aged six to 11 months across the state. Of those, 55% were in Spartanburg County and neighbouring Greenville County.
“These early doses are essential to protecting young children from measles,” she said.
Bell said there are likely a few thousand children and adults, however, who remain unvaccinated against measles in Spartanburg County.
Herd immunity requires 95% coverage
Measles, among the most infectious of pathogens, requires that 95% of the population be vaccinated in order to prevent its spread. In Spartanburg County, 89% of school children have received the required vaccinations, state data show.
Three pediatricians in the Spartanburg area told Reuters the increase in vaccinations likely reflected a variety of patients and motives.
Many parents have sought early MMR shots for children who are six to 11 months old rather than waiting for the first dose normally given at 12 months, doctors said. Parents also have moved up the second dose, which is normally given at age four. The MMR vaccine is 97% effective after two doses.
They added that some families are catching up on routine shots that were missed prior to the outbreak, while other patients may be seeking vaccination after exposure, which can exempt them from quarantine if administered within 72 hours.
Louis Eubank, deputy incident commander for South Carolina’s measles response, said in an email that mobile health units have primarily vaccinated adults, while increases reported by clinics and pharmacies have predominantly been among children under the age of four.
Reaching people who are hesitant about all vaccines, however, and persuading them to come in for the MMR shot has proven difficult, the pediatricians said.
Stuart Simko, a pediatrician at Prisma Health in Greer, South Carolina, in the state’s northwest corner, said the escalation in cases and increased exposure at schools and in the community had recently encouraged more parents to get their children immunised.
“We are getting people who weren’t vaccinated calling. I think we’ve reached that level of, ‘Oh wow. This looks like it’s more than just a smolder. This is starting to catch fire,'” Simko said.
“That fear is starting to pick up among people of going out and understanding you can go to Walmart and be exposed.”