A mother holds her child as she receives a measles vaccine at the Department of Health (DOH) headquarters in Manila on January 21, 2014. The DOH announced a nationwide campaign against measles, targeting 13 million children aged up to five years old. AFP PHOTO / NOEL CELIS / AFP PHOTO / NOEL CELIS        (Photo credit should read NOEL CELIS/AFP/Getty Images)
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An outbreak of measles is spreading across the Philippines – with more than 1,500 cases of the disease and 26 deaths reported in recent weeks, authorities said Thursday.

The capital region of Metro Manila has seen 441 cases, with five deaths, CNN Philippines reports, while many other areas across the country have also been affected.

Those include parts of Luzon and Visayas, with some areas seeing staggering increases in the number of cases of the preventable disease.

The Calabarzon region to the south of Manila has seen a jump of 2,538%, with 575 reported cases so far in 2019 – compared with 21 in 2018. The area has seen nine deaths since the beginning of the year.

“We are expanding the outbreak from Metro Manila to other regions as cases have increased in the past weeks and to strengthen surveillance if there are new cases and alert mothers and caregivers to be more vigilant,” Health Secretary Francisco Duque said.

Vaccinations dipped after Dengvaxia program

Department of Health Undersecretary Eric Domingo said the relatively low number of measles vaccinations in the country could be attributed to the aborted Dengvaxia vaccination program that began in 2016.

In 2017, French pharmaceutical giant Sanofi Pasteur published clinical trial data showing that the dengue vaccine could have unintended consequences in patients who had never been infected with the mosquito-borne virus.

“The analysis confirmed that Dengvaxia provides persistent (protective) benefit against dengue fever in those who had prior infection,” Sanofi said in a statement at the time. “For those not previously infected by dengue virus, however, the analysis found that in the longer term, more cases of severe disease could occur following vaccination …”

The country’s Public Attorney’s Office indicted government officials in connection with deaths linked to the vaccine.

Duque has sought to assure parents that the vaccination for measles is not similar to the Dengvaxia vaccine.

He told parents and caregivers Thursday that the measles vaccines “are safe and have been in use worldwide for decades now,” according to the state news agency.

According to the Department of Health, the number of unvaccinated children has risen by over 100,000 in the last year.