Table of Con­tents | Arti­cle doi: 10.17742/IMAGE.IN.11.2.5 | PDF

Vac­cine Hes­i­tan­cy Holst/Koski

Conversations on Art-Science Collaboration and Vaccine Hesitancy

Johan Holst and Kaisu Koski

Kaisu Kos­ki, a Finnish artist-researcher based in the UK and the Nether­lands, and Johan Holst, a lead­ing vac­ci­nol­o­gist in Nor­way, dis­cuss their col­lab­o­ra­tive work explor­ing vac­cine hes­i­tan­cy in par­ents. The col­lab­o­ra­tion was ini­ti­at­ed as part of Koski’s ongo­ing research in cre­at­ing films for med­ical edu­ca­tion. Togeth­er, the authors devel­oped col­lab­o­ra­tive exchanges on vac­cine-crit­i­cal par­ents’ health beliefs and visu­al­ized them in a mul­ti­modal art­work series. Due to the authors’ dif­fer­ent view­points on vac­cines, this project rais­es ques­tions about posi­tion­al­i­ty in inter­dis­ci­pli­nary research and the pow­er of visu­al­iza­tion in health communication.

Kaisu Kos­ki, un artiste-chercheur fin­landais basé au Roy­aume-Uni et aux Pays-Bas, et Johan Holst, un vac­ci­no­logue de pre­mier plan en Norvège, dis­cu­tent de leur tra­vail de col­lab­o­ra­tion explo­rant l’hésitation au vac­cin chez les par­ents. La col­lab­o­ra­tion a été lancée dans le cadre des recherch­es en cours de Kos­ki en vue de créer des films pour l’enseignement médi­cal. Ensem­ble, les auteurs ont dévelop­pé des échanges col­lab­o­rat­ifs sur les croy­ances en matière de san­té des par­ents cri­tiques de la vac­ci­na­tion et les ont visu­al­isés dans une série d’œuvres mul­ti­modales. En rai­son des dif­férents points de vue des auteurs sur les vac­cins, ce pro­jet soulève des ques­tions sur la posi­tion­nal­ité dans la recherche inter­dis­ci­plinaire et le pou­voir de la visu­al­i­sa­tion dans la com­mu­ni­ca­tion sur la santé.

Fig­ure 1: Kaisu Kos­ki, in col­lab­o­ra­tion with Johan Holst, Con­ver­sa­tions with Vac­cine-Crit­i­cal Par­ents, The­o­ry of Ill­ness #1–4, and Syringe Sequence #1–2, 2015-2017. Instal­la­tion view, UNAIDS, Gene­va, 2017. Pho­to by Annik Wetter.

Overview of the Collaboration

This col­lab­o­ra­tion on vac­cine hes­i­tan­cy emerged as part of artist-researcher Kaisu Koski’s exist­ing arts-based research project in cre­at­ing edu­ca­tion­al films on dif­fer­ent clin­i­cal top­ics for med­ical students.

When vac­cine hes­i­tan­cy was intro­duced as one of the pos­si­ble top­ics to tack­le in the <Immune Nations> project’s first work­shop in Ottawa in August 2015, it seemed like an inter­est­ing aspect to under­take for Kos­ki, con­sid­er­ing her ambiva­lent feel­ings regard­ing vac­cines. While she was ini­tial­ly unsure whether col­lab­o­rat­ing with Holst would be a good idea giv­en the expec­ta­tion for dif­fer­ences of opin­ion, she ulti­mate­ly decid­ed that explo­ration of ten­sions between the con­trast­ing view­points would be fruit­ful. Kos­ki approached Johan Holst, a lead­ing vac­cine sci­en­tist in Nor­way, in the months fol­low­ing the work­shop, after he dis­trib­uted pub­li­ca­tions to the whole project group about the grow­ing chal­lenge to soci­ety from vac­cine hes­i­tan­cy. Inspired by these arti­cles and the lim­it­ed visu­al­iza­tions they pro­vid­ed, Kos­ki sug­gest­ed that the two work togeth­er to respect­ful­ly explore the rela­tion­ship between vac­cine hes­i­tan­cy and vac­cine science.

While Holst was enthu­si­as­tic about Koski’s sug­ges­tion for col­lab­o­ra­tion, acknowl­edg­ing the need for new and fresh approach­es to this issue, he also felt quite out­side his com­fort zone. Part of his per­son­al moti­va­tion and aim was to com­mu­ni­cate more effec­tive­ly with those out­side the field of vac­cine sci­ence and pol­i­cy. The issue of vac­cine hes­i­tan­cy was not new to him. As a vac­cine devel­op­er for over 30 years, Holst had expe­ri­enced the polit­i­cal­ly and emo­tion­al­ly heat­ed dis­cus­sion around per­tus­sis (whoop­ing cough) in the 1980s, as well as a num­ber of inter­ac­tions with crit­i­cal par­ents and jour­nal­ists in con­nec­tion with an effi­ca­cy tri­al for a Nor­we­gian vac­cine against serogroup B meningo­coc­cal dis­ease (MenB). Most recent­ly, his employ­er, the Nor­we­gian Insti­tute of Pub­lic Health, had to per­form a large epi­demi­o­log­i­cal inves­ti­ga­tion to study if there was any increased risk of myal­gic encephalomyelitis (ME)/chronic fatigue syn­drome (CFS) con­nect­ed to the use of the MenB vac­cine. (The study showed that there was no such neg­a­tive rela­tion­ship between being vac­ci­nat­ed and the seri­ous rare dis­ease.) Such inci­dents led to his con­vic­tion that good com­mu­ni­ca­tion in the area of vac­cine hes­i­tan­cy was cru­cial. Holst’s aim in the col­lab­o­ra­tion was to increase under­stand­ing of vac­cine-hes­i­tant par­ents’ health beliefs and how these influ­ence their vac­cine-crit­i­cal decisions.

Kos­ki began the project by inter­view­ing vac­cine-hes­i­tant or -crit­i­cal par­ents in the Nether­lands and Fin­land. She then iden­ti­fied sev­er­al health beliefs in the inter­view data that seemed rel­e­vant to par­ents’ vac­cine hes­i­tan­cy, and devel­oped artis­tic rep­re­sen­ta­tions of these beliefs with the aim of respect­ful­ly com­mu­ni­cat­ing these bias­es. Drafts of the result­ing art­works, includ­ing dia­gram­mat­ic prints and a short doc­u­men­tary video, were then shared with Holst and became the basis for a num­ber of phone and Skype con­ver­sa­tions between the artist and the sci­en­tist from Novem­ber 2015 to July 2016.1 By devel­op­ing nov­el means of explor­ing the urgent top­ic of vac­cine hes­i­tan­cy, this col­lab­o­ra­tion aimed to pro­vide insights into view­points that are often ignored or maligned, to bet­ter under­stand the beliefs of vac­cine-hes­i­tant par­ents, and to improve health communication.

The final work con­sist­ed of a doc­u­men­tary called Con­ver­sa­tions with Vac­cine-Crit­i­cal Par­ents; a series of four dia­gram­mat­ic prints, The­o­ry of Ill­ness #1-4; and a pho­to series, Syringe Sequence #1-2. The dia­grams, which are also includ­ed in the doc­u­men­tary as “ani­ma­tions,” por­tray vac­cine-crit­i­cal par­ents’ main health beliefs, bor­row­ing from the con­ven­tions of sci­en­tif­ic visu­al­iza­tions. The pho­to series, in turn, includes a range of med­i­c­i­nal plants grown in syringes, dis­played in the dif­fer­ent stages of their life cycle. This series was devel­oped as a response to the par­ents’ appre­ci­a­tion of the “nat­ur­al,” visu­al­iz­ing the kinds of vac­cines they would pos­si­bly per­ceive as ben­e­fi­cial and trustworthy.

Fig­ure 2: Kaisu Kos­ki, The­o­ry of Ill­ness #1 (2017), pre­mi­um fine-art print, Forex mount, 40 x 60 cm. Image cour­tesy of the artist.

Reflections on Conversations with Vaccine-Critical Parents, Theory of Illness #1–4, and Syringe Sequence #1–2

What fol­lows is a dia­logue and reflec­tion on the project’s gen­e­sis, meth­ods, and outcomes.

Kaisu Kos­ki: In terms of select­ing this top­ic, though I had expe­ri­enced cer­tain ambiva­lence towards vac­cines myself, I had not thought of it as my top­ic for <Immune Nations>. It was only at the first work­shop in Ottawa, towards the end of the work­shop, when it was pre­sent­ed as one of the pos­si­ble top­ics we could work with, that I start­ed to real­ly think about it.

Johan Holst: Wasn’t it when I sent a quite large chunk of material—articles focussing on vac­cine hes­i­tan­cy that real­ly sparked your interest—that you saw the pos­si­bil­i­ty of our collaboration?

Kos­ki: Yes, you are right! It was espe­cial­ly one of the dia­grams in a par­tic­u­lar arti­cle where the “Accep­tance Con­tin­u­um” cre­at­ed spe­cial reac­tions in you and some of your col­leagues.2 At the time, I had just inter­viewed one par­ent who was quite rad­i­cal in her beliefs, and I thought, there’s a huge con­trast here between this dia­gram and this person’s beliefs. I asked myself, how would she sit­u­ate her­self on this dia­gram? To my mind, it felt like the dia­gram was lack­ing some­thing, some­thing to make it more per­son­al, which led me to think­ing that I need­ed to try and revi­su­al­ize the dia­gram in a way that she might actu­al­ly be able to place her­self on it. But hon­est­ly, in the first work­shop, my con­cern was how I could even con­tribute to this main project giv­en my par­tial vac­cine hes­i­tan­cy. So that became a key fac­tor for why I chose this top­ic: Why not start with what I’m already experiencing?

Holst: I also think I tried to start in that way. I have been very con­cerned with the dif­fi­cul­ty and the chal­lenges of com­mu­ni­cat­ing with vac­cine-skep­ti­cal par­ents, since I’m a strong believ­er in the pow­er­ful ben­e­fits of vac­cines. If you want to com­mu­ni­cate with peo­ple who hold dif­fer­ent beliefs, I know you can’t just use pure log­ic and strong argu­ments; you can’t just use your own belief. You need to under­stand the oth­er person’s belief and per­cep­tion of the world. That’s what moti­vat­ed me. You, in a way, offered a sort of train­ing dia­logue. That’s how I remem­ber it start­ing; and, of course, I was fas­ci­nat­ed by your inter­pre­ta­tion of the dia­logue you had with the par­ents, and then how you trans­formed it into those very pow­er­ful graphics.

I also liked the com­mu­ni­ca­tion we had, and I think you have had that very strong and clear dri­ve to it. In a way—even though I was occu­pied with many oth­er things—we found ways to stay in con­tact and keep the project going for the two years we were active­ly devel­op­ing the works. It was very inspir­ing. This is some­thing rather unique and mul­ti­dis­ci­pli­nary, a col­lab­o­ra­tion between very dif­fer­ent skills that made this pos­si­ble and interesting.

Kos­ki: Were you skep­ti­cal about any­thing in the beginning?

Holst: Yes, of course, a lit­tle bit. This kind of project is not a typ­i­cal thing that would become impor­tant in my career or that I would be rec­og­nized for. So, I was skep­ti­cal if it was real­ly worth­while for me in the start.

Kos­ki: In terms of your career.

Holst: Yeah, a rather nar­row-mind­ed thought, but through the process I also learned that there are so many oth­er things that real­ly count: shared dia­logue, con­tri­bu­tion, and even plea­sure. The project was not only infor­ma­tive, it was fun!

Kos­ki: For me, because I didn’t know you at all, I was won­der­ing how you would respond when you actu­al­ly found out that we think quite dif­fer­ent­ly. I won­dered how far our dia­logue would be able to go, because with some peo­ple dis­agree­ment is the end of the sto­ry. There were moments when, for instance, your col­leagues saw the dia­grams and you said they found them dis­turb­ing. I think it was the parent’s reflec­tions over “Death as a Nat­ur­al Part of Life” that were tak­en as very provoca­tive. And then I thought, “Okay, does this mean you don’t want to be asso­ci­at­ed any­more with this project?”

Holst: So that was your skep­ti­cism? That I would not be able to play ball and fol­low the whole project through?

Kos­ki: Part­ly, because I had ini­ti­at­ed the project and I guess I felt respon­si­bil­i­ty for its con­tin­u­a­tion. But I also doubt­ed myself, because I made up the con­cept of first inter­view­ing, and then trans­lat­ing the find­ings into dia­grams. It’s not like I do that all the time. It was a new idea. Then, when the time came and I had done the inter­views, I was like, “Okay, now I need to come up with those dia­grams, right?”

Holst: I think you did a good job with those, even though they are not always sci­en­tif­i­cal­ly accu­rate. My inten­tion was not to try to “trick” or con­vince peo­ple to change their belief. Our project was not about that at all.

Kos­ki: No, it’s not. But it’s actu­al­ly quite hard to pin­point or explain to oth­er peo­ple what it is about, because peo­ple assume we have a mes­sage. It’s either “you’re for or against.” That is “war rhetorics” actu­al­ly. It’s hard to explain the impor­tance of hav­ing a dia­logue some­where in between, to meet some­where halfway and work to mir­ror each other’s opin­ions. For exam­ple, the film leaves things in the mid­dle. It doesn’t take sides, but presents both sides in some way. Though one par­ent start­ed to doubt me lat­er, after see­ing the film. “Whose side are you on?,” literally.

Holst: Oh dear, I understand.

Kos­ki: I was shocked at first. Nobody else had said that. I had told each par­ent that I would rep­re­sent their mes­sage and the vac­cine researcher’s mes­sage equal­ly. But this shows how dif­fi­cult it is to be on nobody’s side, espe­cial­ly in a “poly­phon­ic” film like Con­ver­sa­tions with Vac­cine-Crit­i­cal Par­ents. While I asso­ciate with their side because I share some of their con­cerns, in ret­ro­spect per­haps it was con­fus­ing for the par­ents that my dia­logue with a vac­cine researcher was con­duct­ed in such a pos­i­tive atmos­phere. Mak­ing the qua­si-sci­en­tif­ic dia­grams in col­lab­o­ra­tion with you, a sci­en­tist, also pre­sent­ed an inter­est­ing dilem­ma because maybe you were hop­ing for the dia­grams to actu­al­ly com­mu­ni­cate some­thing pro-vac­cine to peo­ple, where­as they actu­al­ly are quite scary if you take the time to real­ly read them. But it was real­ly more about the mean­ing of the dia­grams than about chang­ing someone’s mind. The pur­pose was nev­er that I would cre­ate pro- or anti-vac­cine dia­grams. It was to visu­al­ize the health beliefs and, through that, aim for bet­ter understanding.

I had ini­tial­ly thought one aspect of being able to be vac­cine hes­i­tant would come down to one’s tol­er­ance of ambi­gu­i­ty in life in gen­er­al. I thought maybe sci­en­tists wouldn’t tol­er­ate ambi­gu­i­ty very well because they try to under­stand every­thing. But in the vac­cine-hes­i­tant par­ents’ inter­views, it appeared that while they want to live nat­u­ral­ly and let things take their own course, they still have a very strong need to under­stand why things are hap­pen­ing. So they con­struct nar­ra­tives about the rea­sons for ill­ness, for instance. And actu­al­ly, who am I to say that these nar­ra­tives are not true?

Holst: It is very human and under­stand­able to have or cre­ate an over­ar­ch­ing log­ic to life or par­tic­u­lar events. Sci­en­tists have their way of try­ing to over-ratio­nal­ize and explain all things, in a way to try to have con­trol over things hap­pen­ing. Anoth­er ele­ment is that sci­en­tists try to dis­sect and look at just one fac­tor at a time. “Reduc­tion­is­tic,” I think this approach is called in Eng­lish. Some­times, this way to order or con­trol the world and your life is very under­stand­able. But, in real­i­ty, it’s arti­fi­cial or over­sim­pli­fied because a lot of things, events, and fac­tors inter­mix. The real­i­ty is much, much more com­plex than the arti­fi­cial sit­u­a­tion when you study just one para­me­ter at a time. You can, in such a way, end up with a much skewed or very strange pic­ture of real­i­ty. This is in fact a lim­i­ta­tion in many exper­i­ments and often in the ways a num­ber of sci­en­tists are think­ing. I see this project, <Immune Nations>, as an implic­it crit­i­cism of this approach.

Kos­ki: Well, on a cer­tain metaphor­i­cal lev­el that sci­en­tif­ic approach is not so dif­fer­ent from the par­ents who also try to make iso­lat­ed deci­sions: “Okay, I’m tak­ing this vac­cine but not the oth­er one,” based on con­sid­er­ing risks and ben­e­fits, and also think­ing of them­selves as indi­vid­u­als that are not very active­ly con­nect­ed to the oth­er bod­ies. (This, the issue of herd immu­ni­ty, or, rather, herd pro­tec­tion, is some­thing that one of the oth­er projects in <Immune Nations>, Shad­ow­pox, addressed real­ly well.) It seems that nobody has an overview of everything—of course not—so we just deal with the areas we feel we can han­dle, areas we can some­how mon­i­tor and con­trol. But that is part­ly an illusion.

Holst: Regard­ing the visu­al aspects of your dia­grams, through­out the process I have won­dered about and ques­tioned some of your styl­is­tic deci­sions. We have talked about this quite a bit—actually every time you have intro­duced a new dia­gram! For instance, in The­o­ry of Ill­ness #2, the “active body” is most­ly green. Then you have a grey area mark­ing the ini­ti­a­tion. Can you explain why you have cho­sen that colour scheme? Because for me, log­i­cal­ly, it would be that the dark­est part would be the initiation.

Fig­ure 3: Kaisu Kos­ki, The­o­ry of Ill­ness #2 (2017), pre­mi­um fine-art print, Forex mount, 40 x 60 cm. Image cour­tesy of the artist.

Kos­ki: Well, first­ly the ini­ti­a­tion in this per­spec­tive is not some­thing bad, but an ini­ti­a­tion in becom­ing a whole­some per­son. That’s not the same as the bat­tle on the right side of the dia­gram. But, I see what you mean.

Holst: Then you have no eyes on the body on the right-hand side.

Kos­ki: But that has a rea­son: this body on the left side is active­ly search­ing. The eyes are a metaphor for search­ing for the bac­te­ria, and on the right side of the dia­gram the blue body is hap­pi­ly unaware and fac­ing in the oth­er direction.

Over the course of the project, we not only talked about the dia­grams’ visu­al appear­ance, but also the ter­mi­nol­o­gy I used in them. For exam­ple, The­o­ry of Ill­ness #4 is about dif­fer­ent modes of vac­cine admin­is­tra­tion, and ini­tial­ly I didn’t know what to call these modes. I just called them oral admin­is­tra­tion and mus­cle admin­is­tra­tion, and I also used top­i­cal admin­is­tra­tion for skin. You then intro­duced the word “par­enter­al.”

Holst: Par­enter­al is out­side the oral route: actu­al­ly, from Greek; “para-” mean­ing “next to” or “out­side,” and “entero,” mean­ing “inside” or “gut”—literally, “through the intestines.” So that’s through the blood, through the mus­cle, or direct­ly in your veins; all kinds of admin­is­tra­tion that are not through the oral and rec­tal route; or over the mucosa, that is, via the nose. For some sub­stances, it’s not good to use the mus­cle. For a num­ber of vac­cines, how­ev­er, it is good. You then get a “deposit” for the vac­cine com­po­nents. In the mus­cle, there are a lot of immune-com­pe­tent cells, like den­drit­ic cells (which are even more abun­dant in the deep­er parts of our skin), and the macrophages can then find the anti­gen and process it so the body can make an immune response. While the word “par­enter­al” is very com­mon in med­ical jar­gon, peo­ple who see this dia­gram don’t under­stand it. When you say mus­cle admin­is­tra­tion, it’s much more straight­for­ward and eas­i­er to under­stand. One thing is that—maybe it was intentional—but the fig­ure of the mus­cle admin­is­tra­tion looks ominous—maybe that is intentional?

Fig­ure 4: Kaisu Kos­ki, The­o­ry of Ill­ness #4 (2017), pre­mi­um fine-art print, Forex mount, 40 x 60 cm. Image cour­tesy of the artist.

Kos­ki: Well, yes, because accord­ing to this parent’s the­o­ry some­thing bad is hap­pen­ing, and so I used the hand-draw­ing move­ment in a very intense way, fol­low­ing its path­way through the body. And if you look, the draw­ing shows the vac­cine mess­ing up your brain, which was part of a few par­ents’ nar­ra­tives. The vac­cine is kind of stuck in the con­tain­er of your body, because it can’t be released from a mus­cle, you know. That was the rea­son I made it look like that.

This reminds me, in terms of our find­ings in the actu­al inter­view data, that we noticed that the def­i­n­i­tion of “nat­ur­al” is very impor­tant, because the par­ents com­mu­ni­cat­ed a very strong wish to live a nat­ur­al life. To raise their chil­dren “nat­u­ral­ly.” One of the impor­tant things that we talked about was “What if vac­cines were under­stood as natural?”

Holst: As vac­cine providers—giving lec­tures to stu­dents, com­mu­ni­cat­ing with par­ents, or with rel­a­tives in a cof­fee party—we should empha­size bet­ter some of the key prin­ci­ples in vac­ci­nol­o­gy. How vac­cines work is actu­al­ly by stim­u­lat­ing a very nat­ur­al process. We use a trig­ger­ing or start­ing sig­nal that the body inter­prets as dan­ger (from an intrud­er), and then the defence mech­a­nisms start. Also, then the body’s (immune) mem­o­ry gets built up and you are pro­tect­ed against the actu­al dis­ease the next time you encounter it. I think one should empha­size the fact that vac­cines actu­al­ly work in a very nat­ur­al way. Fol­low­ing stim­u­la­tion by a spe­cif­ic microbe, the body is trig­gered to devel­op its nat­ur­al mech­a­nisms of pro­tec­tion in order to get rid of the infec­tion and lat­er to avoid becom­ing sus­cep­ti­ble to the actu­al dis­ease. Vac­cines can tru­ly be regard­ed as col­lab­o­rat­ing with humans and the body itself. I think we—scientists—haven’t done well enough in this area. Peo­ple often have the per­cep­tion that vac­cines and vac­ci­na­tion are unnat­ur­al and harm­ful. Many of these per­cep­tions and claims are not true. Or, at best, just a lit­tle “pin shot” of truth that has been exag­ger­at­ed. We need to be bet­ter and more respect­ful in the way we deal with this type of com­mu­ni­ca­tion than we have been. Art and artists can cer­tain­ly help us with this.


Johan Holst would like to thank Drs. Lis­beth Mey­er Næss and Hanne Nøk­le­by, col­leagues at Nor­we­gian Insti­tute of Pub­lic Health for fruit­ful and con­struc­tive dis­cus­sions of art­works and view­points dur­ing the active col­lab­o­ra­tive exchange-phase with Kaisu Koski.

Kaisu Kos­ki would like to thank all those par­ents who gen­er­ous­ly vol­un­teered to be inter­viewed for this study. She is also grate­ful to Pro­fes­sor Kati Hakkarainen for her feed­back dur­ing the inter­view process from micro­bi­o­log­i­cal, clin­i­cal, and edu­ca­tion­al per­spec­tives. Koski’s par­tic­i­pa­tion in the <Immune Nations> project was finan­cial­ly sup­port­ed by the Acad­e­my of Fin­land and Tam­pere University.

Image Notes

Fig­ure 1: Kaisu Kos­ki, in col­lab­o­ra­tion with Johan Holst, Con­ver­sa­tions with Vac­cine-Crit­i­cal Par­ents, The­o­ry of Ill­ness #1–4, and Syringe Sequence #1–2, 2015-2017. Instal­la­tion view, UNAIDS, Gene­va, 2017. Pho­to by Annik Wetter.

Fig­ure 2: Kaisu Kos­ki, The­o­ry of Ill­ness #1 (2017), pre­mi­um fine-art print, Forex mount, 40 x 60 cm. Image cour­tesy of the artist.

Fig­ure 3: Kaisu Kos­ki, The­o­ry of Ill­ness #2 (2017), pre­mi­um fine-art print, Forex mount, 40 x 60 cm. Image cour­tesy of the artist.

Fig­ure 4: Kaisu Kos­ki, The­o­ry of Ill­ness #4 (2017), pre­mi­um fine-art print, Forex mount, 40 x 60 cm. Image cour­tesy of the artist.


  1. A detailed descrip­tion of their process of col­lab­o­ra­tion is avail­able in Kaisu Kos­ki and Johan Holst, “Explor­ing Vac­cine Hes­i­tan­cy through an Artist-Sci­en­tist Col­lab­o­ra­tion: Visu­al­iz­ing Vac­cine-Crit­i­cal Par­ents’ Health Beliefs,” Jour­nal of Bioeth­i­cal Inquiry, vol. 14, no. 3, 2017, pp. 1–16.

  2. The arti­cle Holst pro­vid­ed Kos­ki was Noni E. Mac­Don­ald, “Vac­cine Hes­i­tan­cy: Def­i­n­i­tion, Scope and Deter­mi­nants,” Vac­cine, vol. 33, no. 34, 2015, pp. 4161–64, https://​doi​.org/​1​0​.​1​0​1​6​/​j​.​v​a​c​c​i​n​e​.​2​0​1​5​.​0​4​.​036.