Taguig, Philippines - Seated on his mother's lap, one-year old Jeon Tyler Ancheta gets vaccinated for measles and rubella. Jeon Tyler lets out a short cry after the needle is pulled out of his arm, but he's comforted by his mother while a doctor enthusiastically says "good."

There's a line of parents who brought their kids to get vaccinated at this local health clinic. It's a positive sign in a country that has a large number of unvaccinated children.

The Philippines has about one-million children who have not received a single routine vaccination according to the United Nations Children's Fund (UNICEF). The country is ranked in the top five globally for the highest number of zero-dose children. In addition, there are many kids who are only partially vaccinated for diseases that require multiple shots including measles.

So, health departments across the country have teamed up with UNICEF and the World Health Organization for a nationwide vaccine campaign.

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Robert Pascual Jr. came to this clinic with his two-year old daughter Zafeerah. "When she grows up, I want her to be protected and safe," Pascual said although he acknowledged having some vaccine hesitancy until recently.

The reasons behind the high number of unvaccinated children in the Philippines include strict lockdowns during the pandemic that kept families from routine medical appointments.

67 Million Children Missed Vaccines During Pandemic, UNICEF Says

Many Filipinos also have lingering mistrust of vaccines after more than 800,000 Filipino children received a dengue vaccine, Dengvaxia, which was later shown to increase the risk of a severe form of the disease in some people.

Several studies show the Dengvaxia debacle caused a drop in Filipino parents' trust of vaccines, even with vaccines that have been routine for children for decades. Health officials in the Philippines say this led to measles outbreaks.

"There are myths that these particular vaccines give you the disease itself. So, there's a lot of controversies," says Dr. Jennifer Lou Lorico-De Guzman, medical coordinator for the national immunization program for the city of Taguig.

"We are trying to educate the public about the importance of vaccines," she adds.

Health advocates such as Ma. Nieves Bulalacao are hitting the streets to talk to parents. On a recent morning, Bulalacao walked through Taguig's side streets and alleyways alongside nurse Gigi Quintero who carried a cooler stocked with ice packs and vaccines for measles as well as rubella.

In Taguig, Philippines, May 18, 2023, health workers including Ma. Nieves Bulalacao hit the streets going door to door to educate parents on the importance of routine vaccines for children.

"We're trying to find parents with children who need to be vaccinated," Bulalacao said.

Together they went door to door telling parents how contagious diseases like measles are and that vaccines are the best way to protect their children.

They came across Stephanie Opider whose three children need to be vaccinated. "It's dangerous because measles can spread quickly," Bulalacao told Opider.

The children's father, Joeson Dalanon, is afraid vaccinations could harm their kids. "I hear there are lots of kids who die so I didn't want them to get vaccinated," Dalanon said.

In Taguig, Philippines, May 18, 2023, parent Joeson Dalanon holds his one-year-old son Nick Maron. Dalanon told VOA "I hear there are lots of kids who die" from vaccines.

These parents are especially concerned about their middle child, three-year-old King Andrei, who they say gets convulsions whenever he gets a fever.

Eventually the parents agree, seemingly reluctantly, to let Quintero vaccinate all three of their children. Bulalacao acknowledges that more work needs to be done so that parents can feel confident that vaccination is the right decision. "We have to keep reassuring them that these routine vaccines will not harm their kids," she said.

At a clinic in Taguig's Maharlika neighborhood, Suhaira Bago lines up with her two-year-old daughter Alicia for a measles and rubella vaccination. They're part of this neighborhood's Muslim community and Bago says some families refuse to let their children get inoculated.

Two-year-old Alicia Musa gets vaccinated for measles and rubella at a public health clinic in Taguig, Philippines, May 18, 2023.

"Many of the [grandparents] have a lot of influence over these decisions in their family," Bago says. "They say they didn't get the vaccine so their [grandchildren] don't need it either. The issue with the [Dengvaxia] vaccine only added to this feeling for many."

Cristina Rakim, a city health worker in this neighborhood who's also Muslim, says outreach teams are investing significant time in this community. "We're trying to convince parents and grandparents how much safer their children and grandchildren will be if they're vaccinated," Rakim said.

Two-year-old Alicia didn't even flinch when the needle went in and out of her arm. Her mother smiled when she later said, "I know this measles and rubella vaccine will protect my child."