Building Confidence in Routine Immunization in the Philippines
UNICEF Philippines Insights for Impact Project with Data for Good at Meta

Background
The Immunization Agenda 2030 aims to make vaccination available to everyone, everywhere, by 2030.1 The COVID-19 pandemic and associated disruptions have strained health systems in 2020 and 2021. Data from the WHO/UNICEF Estimates of National Immunization Coverage (WUENIC) published in June 2022 showed that 25 million children are under-immunized, 6 million more than in 2019 and the highest number since 2008. The number of children missing out on any vaccination - “zero-dose children”2 increased by 5 million in 2021 from 2019, going from 13 to 18 million worldwide.
Immunization helps protect every child’s right to good health. However, routine immunization coverage among children in the Philippines has not reached the ideal 95% target, with the coverage rate for many vaccines declining from 2010 to 2021.3 This resulted in measles and polio outbreaks in the country in 2019, placing children at risk of these life-threatening diseases.4 5In addition to these challenges, fear of entering health facilities and disruptions in the healthcare system overall during COVID-19 only exacerbated declining routine immunization rates. Between 2019 and 2021, there were estimated declines in the coverage of DTP1, DTP3, measles, and BCG from roughly 75% to 57%.6 In 2021, the Philippines was listed as one of 10 countries with the highest number of zero dose children worldwide.7
Research
To better understand the trends associated with vaccine hesitancy in the Philippines, the Data for Good team at Meta analyzed a combination of public posts about vaccinations on Facebook, as well as insights about trust in health care systems from the global COVID19 Trends and Impact Survey. A qualitative assessment of the public conversation around this topic on Facebook found that there was some distrust toward vaccination programs and concerns about vaccine safety. Though the analysis revealed salient concerns in the Philippines, there were positive feelings towards vaccines overall as well, including people expressing appreciation for healthcare workers and local officials promoting the country’s routine immunization campaign, and many people sharing stories about getting vaccinated. At the time of analysis in April 2021, the most prominent reasons for hesitancy among public posts and in survey data were the politicization of vaccination programs and concerns over side effects.
Campaigns
Using these insights, the Yale Institute for Global Health, UNICEF and Meta developed five campaigns, four in Filipino and one in English, which targeted people aged 18-55 years in the Philippines in order to increase confidence in routine vaccination. With content designed by Public Good Projects, all campaigns linked to a UNICEF resource page which had information about routine immunizations for children.

Campaigns themes:
- Addressing Concerns with Emphasis on Safety and Efficacy (in Filipino language): Since Facebook public posts revealed that vaccine safety was a prominent concern, this campaign focused on providing parents with information about how vaccines are both safe and effective. This campaign included information on vaccine safety. Additionally, the campaign included hashtags found in popular pro-vaccine posts, and surfaced the norm that childhood vaccines are used around the world in a variety of settings.
- Increasing Salience for Self-Efficacy, Response-Efficacy and Self- Agency for Vaccination in threat of Vaccine Preventable Diseases (VPD) (in Filipino): Given that concerns about vaccines are driven by worry about children’s well-being, this campaign emphasized that vaccinating children is a powerful tool for both protecting and caring for them. This message attempted to turn the worry about vaccination side effects on its head by showcasing vaccines as a way to ease worry and give parents peace of mind.
- Values-based Messages [Liberty-Values based] (in Filipino): Given that the analysis of posts suggested that there was some lack of public trust in vaccines, this campaign sought to emphasize liberty and parental agency in the decision to vaccinate their children. Using messaging like “The safety of your child is in your hands,” the campaign attempted to show that parents are free to have their children vaccinated and this is ultimately their choice.
- Testimonials/Storytelling with Health Professionals and Parents (in Filipino/English): This campaign used the common approach of testimonials and storytelling with two unique types of messengers. The testimonials campaign featured messages from healthcare workers on the importance of vaccines and the protection they afford. Trust in healthcare workers has been a consistent finding across Insights for Impact analyses and in the Philippines, both public posts and survey data alike indicated a high level of appreciation and trust for this group. The testimonials also leveraged the concept of social norms and included stories from parents who either plan to or have had their children vaccinated, including a UNICEF Goodwill Ambassador. Social norming approaches have shown to be an effective way of influencing people’s attitude towards vaccination and reducing their hesitancy, especially if the message is coming from people in the same context whom parents are likely to trust. Two versions of this campaign were run, one in English and one in Filipino.
UNICEF, Yale and Meta tested the effectiveness of these four approaches over a three-week period in July-August 2021. Viewers of each ad set were randomly divided into two groups – those that saw the ads and those that did not, and viewers from both groups were randomly surveyed to determine whether the ads successfully influenced attitudes on vaccination. The post-campaign survey for all campaigns tested for three common results, including recall of the campaign itself, the importance of childhood vaccination and the likelihood of recommending childhood vaccination to others. Post-campaign surveys also tested two questions specific to each message type (Table 1).
Results
The four campaigns reached a combined total of over 17.9 million people in the Philippines and achieved high recall among those who saw the various messages, indicating the content was memorable across the board. More importantly, every campaign was successful in achieving a statistically significant lift in post-campaign results about both the importance of childhood vaccines and the likelihood that people would recommend childhood vaccination to others (see Table 1 for results). These questions were used as metrics for measuring relative effectiveness of campaigns as they provided the closest reflection of willingness to vaccinate.
The testimonial campaign in Filipino achieved statistically significant outcomes across all survey questions. The campaign worked well for improving the likelihood that people would advise their close friends to vaccinate their children. While the testimonial content in Filipino earned consistently strong results, the liberty-values based campaign achieved a higher lift on vaccine importance and a comparable lift on likelihood that people would recommend immunization to their friends/family.
Despite not lifting specific attitudes towards vaccine safety and effectiveness, the message addressing vaccine safety and efficacy was successful in increasing both attitudes toward vaccine importance, and willingness to recommend vaccination. The campaign achieved a statistically significant 2.1 percentage point lift on both metrics, which would potentially equate to over 224,000 additional people recommending that friends and family vaccinate their children, and endorsing the importance of vaccinating children. Self-efficacy and liberty-based messages also achieved statistically significant lifts (1.6 and 1.8 percentage points, respectively), which would potentially mean between 144,000 – 160,000 people recommending that friends and family vaccinate their children. The overall success of these campaigns demonstrates the strong potential of these messages which were informed by public post analysis, and co-created with the UNICEF Philippines team.
Study Questions |
Q1. Do you remember seeing a post about routine immunizations/from UNICEF online or on a mobile device over the past 2 days? |
Q2. How important is it for parents to get their children vaccinated? |
Q3. How likely are you to advise a close friend or relative who has a child to get him or her vaccinated? |
Q4. Custom (campaign specific) |
Q5. Custom (campaign specific) |
---|---|---|---|---|---|
Campaign 1 (FIL): Addressing Concerns with Emphasis on Safety and Efficacy | +0.2 | +2.1* | +2.1* | +0.7 | No lift |
Campaign 2 (FIL): Increasing Salience for Self-Efficacy, Response-Efficacy and Self- Agency for Vaccination in threat of VPD | +0.5 | +1.8* | +1.6* | +3.4* | +1.6* |
Campaign 3 (FIL): Values-based Messages [Liberty-Values based] | +1.6* | +2.3* | +1.8* | +2.0* | No lift |
Campaign 4a (FIL) Testimonials/ Storytelling with Messengers | +2.3* | +1.7* | +2.0* | +1.5* | +2.7* |
Campaign 4b (ENG) Testimonials/ Storytelling with Messengers | No lift | +2.4* | +1.6* | No lift | +2.2* |
Campaign performance reflects the chance of *brand lift 90% or greater and ^brand lift 80% or greater
Influencing Vaccine Decision-making Moving Forward
Vaccine decision-making is complex and influenced by individual experiences, knowledge, attitudes, and even values and beliefs. Changing vaccine attitudes and behaviors often requires multiple nudges at several levels to be effective, including programs that target individuals, communities and the policy landscape.
Observing statistically significant outcomes as a result of a digital campaign across all messages tested, is a substantial accomplishment, showcasing how online outreach can influence complex decision-making at a low cost per person reached, as well as providing valuable insights to UNICEF and Yale that can be applied to future vaccine communications.
Learnings that can be applied to future vaccination campaigns include:
- Address prominent concerns surfaced by the community: The message on vaccine efficacy and safety directly addressed the most common concerns about vaccines and was most successful in its potential impact on vaccine uptake, with lift in importance and recommendations to friends and family. Similarly, the effectiveness of the self-efficacy message, with its emphasis on vaccines keeping children safe, suggests that even indirect incorporation of community concerns can increase parents’ likelihood to vaccinate.
- Message in local languages: Campaign results highlight the importance of messaging in local languages. Of the two campaigns that used storytelling and testimonials, the one in Filipino achieved the largest ad recall of all campaigns and reached nearly a million more people than the English version, which did not achieve statistically significant recall. This finding is similar to previous Insights for Impact results that have found content in local languages to achieve higher memorability among the target population.
- Consider value-based messaging, especially when trust is low: Given distrust that parents have about immunization programs, the success of the liberty-based campaign suggests that value-based messaging may be particularly impactful in the Philippines. Liberty-based messaging may be particularly effective in environments where parents’ skepticism towards vaccination programs hinder vaccine uptake.
- Use testimonials and storytelling from trusted messengers: Storytelling campaigns in the Philippines confirmed that authentic testimonials and stories are powerful mechanisms for affecting change, a finding that was also borne out in previous Insights for Impact campaigns. These messaging approaches demonstrate the power of social norming, storytelling, and the importance of sharing information from trusted and relatable sources.
Yale and UNICEF plan to leverage these insights to inform evidence-based vaccine messaging strategies, which aims to help increase vaccine acceptance across the countries in which they work.8 The partnership is currently active in ten countries supporting routine childhood immunization in 2022.
“This partnership with Meta and the Yale Institute for Global Health has provided us with the data that parents and caregivers in the Philippines consider childhood vaccinations important to them. Additionally, this work has also shown us that there is an increased likelihood that people will recommend childhood vaccination to their peers. UNICEF hopes that these positive intentions to vaccinate will now contribute to reduce the number of unvaccinated and under vaccinated children in the Philippines”. Dr. Ephrem Tekle Lemango, Associate Director – Health/Chief of Immunisation, UNICEF HQ
"The collaboration in the Philippines is an incredible opportunity to learn from the power of social media for health promotion. In recent years, my research group and others have found promising leads on how to influence people’s health behavior and these insights provided us the opportunity to evaluate at scale,” said Dr. Saad Omer, Director of the Yale Institute for Global Health. “The major strength of this effort is the collaboration - particularly with Facebook, UNICEF, and other partners - where we bring together all our unique strengths to address one of the most pressing issues facing global health, vaccine confidence.”
"Our collaborations with UNICEF and Yale have been among the most important global partnerships that our team has ever undertaken," said Laura McGorman, Policy Director for Data for Good at Meta. "We value the expertise of these health organizations tremendously and look forward to continuing these efforts to increase adoption of childhood immunizations and protect children from life-threatening illness across the world."
2 Zero dose children are those who lack any dose of DTP (i.e., diphtheria, tetanus, and pertussis vaccine). Under-vaccinated are those who received one dose, but not a third protective dose.
3 Immunization Philippines 2021 country profile (who.int)
4 UNICEF urges parents to get children immunized; calls for collective actions to fight measles
5 WHO, UNICEF and partners support Philippine Department of Health’s polio outbreak response
6 Immunization Philippines 2021 country profile (who.int)
7 Vaccination and Immunization Statistics - UNICEF DATA
8 Vaccine messaging guide | UNICEF