Table 3. Illustrative quotes for individual barriers.

Quote ID	Theme	Illustrative quote
I1	Vaccine brand hesitancy and brand preferences	I had concerns with Sinovac. I read about the studies published about vaccines and Sinovac initially did not publish their results. For me, I did not want Sinovac. […] There was even a time when the Department of Health said, “Sinovac is not for health workers”. I still think some vaccines are better than others (A1, 51–60 years old, male, Laguna).
I2	Vaccine brand hesitancy and brand preferences	I had myself registered, then I did not go, then I registered, then did not go. Then when I went through the third registration, they [local government unit] asked in their website, “Why did you not show up the last time you were scheduled”? The choices for refusal were: conflict in schedule, choice of vaccine, and three other reasons. I chose choice of vaccine. After that, they scheduled me to another vaccination site to get my vaccine. When I went, I was still not in any way sure that it was Pfizer. But I knew it would not be Sinovac. So I was open to whatever vaccine it will be, except for Sinovac. So knowing that it was not Sinovac convinced me to go. Well, regardless if it was AstraZeneca or other vaccines, I was okay with it as long as it was not Sinovac. Because I heard that they used the same virus, they cased it in the vaccine, and it was like you will have the virus in your body? So the negativity as well as the news about it. That was really a major reason that I wouldn’t go for Sinovac (A3, 41–50 years old, female, National Capital Region).
I3	Negative experiences with the health system as source of vaccine hesitancy and anti-vaccination sentiments	I self-study medicine because I do not want to depend on doctors. If I did, maybe I died a long time ago. […] Once upon a time in my life, I was admitted in the hospital. I was later diagnosed with UTI [urinary tract infection] but was initially asked for an ultrasound because they thought I was pregnant. Another doctor asked me to drink beer for my UTI. From that [day] on, I just self-studied medicine. With COVID, I don’t really believe [what I read and hear] without validation. A former scientist working at Pfizer insisted that vaccines do not help COVID-19. Because vaccines are not good for our body. […] And even the medical practitioners or doctors themselves cannot help if someone suffers the adverse reaction of the vaccine (A1, 51–60 years old, female, Misamis Oriental).
I4	Negative experiences with the health system as source of vaccine hesitancy and anti-vaccination sentiments	I was working in a school and was looking after a child whose mother was busy. The child was very smart, but was diagnosed with autism. When he had check-ups, I would accompany him and observe. Then I researched about autism, and found that it is caused by vaccines. No wonder there are many children with autism; it is associated with vaccines (A2, 61–70 years old, female, Camarines Norte).
I5	Negative experiences with the health system as source of vaccine hesitancy and anti-vaccination sentiments	When my child was in Grade 5, she was injected with Dengvaxia and had rashes and headaches. I did not know until my child told me because there were children dying from Dengvaxia. My child completed three doses causing her to feel unwell. I did not know it was Dengvaxia; I thought the form I signed was for anti-dengue. My husband and I just prayed because we were afraid. One classmate of hers even died because of Dengvaxia, although there was no proof and autopsy was not done. After that experience, I no longer allow my children to get any of the vaccines. I am also not vaccinated against COVID-19 (B2, 41–50 years old, female, National Capital Region).
I6	Negative experiences with the health system as source of vaccine hesitancy and anti-vaccination sentiments	I am more afraid of vaccines. Once you inject that into your body, you will not be able to reverse its effects or take it out of your system. With COVID, if you are just careful and follow health protocols, and strengthen your immune system, I do not think you will immediately get sick. Compared to the vaccines–we are not sure how safe they are (B2, 41–50 years old, female, National Capital Region).
I7	Vaccines are viewed as unsafe and deadly	So I told my son, “Why do we need a booster”? Because you know, if it’s not really 100% [effective], you need a booster after 6 [months] or 1 year. You know what, my son answered me, "You know mom, if you don’t die from the first dose, they give you a second dose to make sure that you really die. If you don’t die from the second dose, then they give you a booster”. It’s funny, it’s funny (A2, 71–80 years old, female, Misamis Oriental).
I8	Vaccines are viewed as unsafe and deadly	As early as now, we see that after vaccination, people are dying. Although medical professionals do not claim that it is caused by the vaccine. But if we really apply the law of proximate cause… Those individuals who went to the site to get vaccinated are healthy, even though they have comorbidities they were okay prior getting the vaccine. Why is it after the vaccination, a person will just suddenly die? […] But then, the doctors would just say that it was not caused by the vaccine… that it was because of his comorbidity. Before vaccination, he was [alive] and kicking. But after vaccination, this senior citizen in our place just died. So this is what we are saying. If the vaccine is really a guarantee to solve this problem, then it should not cause mortality (A1, 51–60 years old, female, Misamis Oriental).
I9	Vaccines are viewed as unsafe and deadly	I do not want mRNA vaccines. Once you play around with RNA, you just don’t know [what happens after]. The technology is not yet mature (A2, 71–80 years old, male, Laguna).
I10	Vaccines are viewed as unnecessary and insufficient to prevent disease	The elderly are just at home. In other words, they [we] do not go out and interact with people. The vaccine should just be given to the frontliners and those working in the health care sector (A2, 61–70 years old, female, Camarines Norte).
I11	Vaccines are viewed as unnecessary and insufficient to prevent disease	The elderly and those with comorbidities–they need the vaccine more than I do. In my experience of getting COVID, I only had mild disease. I know that my body can survive. But how about them? How will they survive? (A4, 21–30 years old, female, National Capital Region).
I12	Vaccines are viewed as unnecessary and insufficient to prevent disease	Just because you are vaccinated, it does not mean you are safe from COVID-19. So why should you get the vaccine if you are still not safe in the end? My question is, what are the vaccines for then? (B2, 41–50 years old, female, National Capital Region).
I13	Skepticism towards vaccine incentives	If the vaccine is really that good, then people should be fighting each other to get it. But how come the government has to give you an incentive to get the vaccine? […] If it’s really that good, why the incentive? If it’s really that good. That’s why it bothers me. […] If it is for your protection, if it is for your health, we do not need that [incentive] (A2, 71–80 years old, female, Misamis Oriental).
I14	Use of vaccines not fully approved by the Food Drug and Administration	It [the vaccine] needs to under a thorough process or take many years to have enough clinical studies that can validate the results or so we can see the adverse reactions in the human body. I don’t think it’s [the development process] this easy that in just a matter of months, we can already use it, right? I don’t think it’s this easy for them to say that the vaccine is effective to combat the virus (A1, 51–60 years old, female, Misamis Oriental).
I15	Use of vaccines not fully approved by the Food Drug and Administration	I was thinking, maybe this is just an experiment or study. As in the dengue vaccine, they were just studying it and injected it among children, and then found it wasn’t safe. I am thinking the same for COVID-19 vaccines (B2, 41–50 years old, female, National Capital Region).
I16	Low health literacy and lack of critical skills to evaluate health information	I noticed educating people is lacking. For example, the father of our house help does not want to get the vaccine because of Dengvaxia. The people we know who belong to lower income groups always say, Dengvaxia. It is frustrating because people are not well-informed about vaccines (A4, 31–40 years old, male, Rizal).
I17	Low health literacy and lack of critical skills to evaluate health information	What people know is superficial and information is not thoroughly discussed in social media or even in informercials of local governments. So what happens sometimes is, they do get side effects like fever, chills during the first vaccination. Then they do not return for the second, which is a wasted opportunity (A1, 51–60 years old, female, Rizal).
I18	Low health literacy and lack of critical skills to evaluate health information	They say the vaccines change your DNA. I don’t know. Actually, I don’t know what to believe in. If I’m being honest, I don’t know what to believe in (A2, 61–70 years old, female, Camarines Norte).
I19	Religious beliefs do not support vaccines	God created natural antibodies, but these will be replaced by man-made vaccines. Nothing can replace what God has created, which may be the reason for the side effects and deaths (A1, 51–60 years old, female, Misamis Oriental).