When do persuasive messages on vaccine safety steer COVID-19 vaccine acceptance and recommendations? Behavioural insights from a randomised controlled experiment in Malaysia

Nicholas Yee Liang Hing, Yuan Liang Woon, Yew Kong Lee, Hyung Joon Kim, Nurhyikmah M Lothfi, Elizabeth Wong, Komathi Perialathan, Nor Haryati Ahmad Sanusi, Affendi Isa, Chin Tho Leong, Joan Costa-Font, Nicholas Yee Liang Hing, Yuan Liang Woon, Yew Kong Lee, Hyung Joon Kim, Nurhyikmah M Lothfi, Elizabeth Wong, Komathi Perialathan, Nor Haryati Ahmad Sanusi, Affendi Isa, Chin Tho Leong, Joan Costa-Font

Abstract

Introduction: Vaccine safety is a primary concern among vaccine-hesitant individuals. We examined how seven persuasive messages with different frames, all focusing on vaccine safety, influenced Malaysians to accept the COVID-19 vaccine, and recommend it to individuals with different health and age profiles; that is, healthy adults, the elderly, and people with pre-existing health conditions.

Methods: A randomised controlled experiment was conducted from 29 April to 7 June 2021, which coincided with the early phases of the national vaccination programme when vaccine uptake data were largely unavailable. 5784 Malaysians were randomly allocated into 14 experimental arms and exposed to one or two messages that promoted COVID-19 vaccination. Interventional messages were applied alone or in combination and compared against a control message. Outcome measures were assessed as intent to both take the vaccine and recommend it to healthy adults, the elderly, and people with pre-existing health conditions, before and after message exposure. Changes in intent were modelled and we estimated the average marginal effects based on changes in the predicted probability of responding with a positive intent for each of the four outcomes.

Results: We found that persuasive communication via several of the experimented messages improved recommendation intentions to people with pre-existing health conditions, with improvements ranging from 4 to 8 percentage points. In contrast, none of the messages neither significantly improved vaccination intentions, nor recommendations to healthy adults and the elderly. Instead, we found evidence suggestive of backfiring among certain outcomes with messages using negative attribute frames, risky choice frames, and priming descriptive norms.

Conclusion: Message frames that briefly communicate verbatim facts and stimulate rational thinking regarding vaccine safety may be ineffective at positively influencing vaccine-hesitant individuals. Messages intended to promote recommendations of novel health interventions to people with pre-existing health conditions should incorporate safety dimensions.

Trial registration number: NCT05244356.

Keywords: COVID-19; Health education and promotion; Public Health; Randomised control trial; Vaccines.

Conflict of interest statement

Competing interests: HJK and EW are employees of UNICEF Malaysia and assisted with administrating the funds that supported the work reported in this paper. Funding was channelled from the funder to UNICEF Malaysia under a cooperation agreement.

© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.

Figures

Figure 1
Figure 1
Experimental design flow chart presenting sample size, arm allocations, and item wordings for outcomes.
Figure 2
Figure 2
Average marginal effects for each interventional arm relative to the control arm based on changes in the predicted probability of responding with a positive intent for each primary outcome measure: (1) intention to vaccinate, (2) recommend to healthy adults (Healthy adults), (3) recommend to the elderly (Elderly), (4) recommend to people with pre-existing health conditions (Health condition). Forest plots present point estimates, 95% CIs, and the line of indifference.
Figure 3
Figure 3
Sociodemographic determinants of average marginal effects with respect to age, sex, and education level, for each interventional arm relative to the control arm based on changes in the predicted probability of responding with a positive intent for each primary outcome measure: (1) intention to vaccinate, (2) recommend to healthy adults (Healthy adults), (3) recommend to the elderly (Elderly), (4) recommend to people with pre-existing health conditions (Health condition). Forest plots present point estimates, 95% CIs, and the line of indifference.

References

    1. Cohen J. Shots of hope. Science 2020;370:1392–4. 10.1126/science.370.6523.1392
    1. Randolph HE, Barreiro LB. Herd immunity: understanding COVID-19. Immunity 2020;52:737–41. 10.1016/j.immuni.2020.04.012
    1. Polack FP, Thomas SJ, Kitchin N, et al. . Safety and efficacy of the BNT162b2 mRNA Covid-19 vaccine. N Engl J Med 2020;383:2603–15. 10.1056/NEJMoa2034577
    1. Lopez Bernal J, Andrews N, Gower C, et al. . Effectiveness of the Pfizer-BioNTech and Oxford-AstraZeneca vaccines on covid-19 related symptoms, hospital admissions, and mortality in older adults in England: test negative case-control study. BMJ 2021;373:n1088. 10.1136/bmj.n1088
    1. China Sinovac Shot Seen Highly Effective in Real World Study. Bloomberg News, 2021. Available: [Accessed 21 Feb 2022].
    1. Jara A, Undurraga EA, González C, et al. . Effectiveness of an inactivated SARS-CoV-2 vaccine in Chile. N Engl J Med 2021;385:875–84. 10.1056/NEJMoa2107715
    1. Sallam M. COVID-19 vaccine Hesitancy worldwide: a Concise systematic review of vaccine acceptance rates. Vaccines 2021;9:160. 10.3390/vaccines9020160
    1. The World Health Organization . Report of the SAGE working group on vaccine hesitancy; 2014.
    1. Global attitudes on a COVID-19 vaccine. Ipsos; 2020. [Accessed 21 Dec 2021].
    1. Wong LP, Alias H, Wong P-F, et al. . The use of the health belief model to assess predictors of intent to receive the COVID-19 vaccine and willingness to pay. Hum Vaccin Immunother 2020;16:2204–14. 10.1080/21645515.2020.1790279
    1. Syed Alwi SAR, Rafidah E, Zurraini A, et al. . A survey on COVID-19 vaccine acceptance and concern among Malaysians. BMC Public Health 2021;21:1129:1–12. 10.1186/s12889-021-11071-6
    1. Zahiid SJ. Health Ministry survey shows a third of Malaysians still fear, doubt Covid-19 vaccine. Malay Mail, 2020. Available: [Accessed 20 Feb 2021].
    1. Neely SR, Eldredge C, Ersing R, et al. . Vaccine hesitancy and exposure to misinformation: a survey analysis. J Gen Intern Med 2022;37:179–87. 10.1007/s11606-021-07171-z
    1. Thaler R, Sunstein CR. Nudge: Improving Decisions about Health, Wealth and Happiness. Yale University Press, 2008.
    1. Bálint KE, Bilandzic H. Health communication through media narratives: factors, processes and effects. Int J Commun 2017;11:4858–64.
    1. Reñosa MDC, Landicho J, Wachinger J. Nudging toward vaccination : a systematic review. BMJ Glob Heal 2021;6:1–20. 10.1136/bmjgh-2021-006237
    1. Motta M, Sylvester S, Callaghan T, et al. . Encouraging COVID-19 vaccine uptake through effective health communication. Front Polit Sci 2021;3:1–12. 10.3389/fpos.2021.630133
    1. Huang Y, Liu W. Promoting COVID-19 vaccination: the interplay of message framing, psychological uncertainty, and public agency as a message source. Sci Commun 2022;44:3–29. 10.1177/10755470211048192
    1. Ohtake F. Can nudges save lives? Jpn Econ Rev 2022;73:245-268. 10.1007/s42973-021-00095-7
    1. Sasaki S, Saito T, Ohtake F. Nudges for COVID-19 voluntary vaccination: how to explain peer information? Soc Sci Med 2022;292:114561. 10.1016/j.socscimed.2021.114561
    1. James EK, Bokemper SE, Gerber AS, et al. . Persuasive messaging to increase COVID-19 vaccine uptake intentions. Vaccine 2021;39:7158–65. 10.1016/j.vaccine.2021.10.039
    1. Chang T, Jacobson M, Shah M, Pramanik R, Shah SB. Financial incentives and other nudges do not increase COVID-19 vaccinations among the vaccine hesitant. NBER; 2021. [Accessed 25 Feb 2022]. 10.3386/w29403
    1. Ye W, Li Q, Yu S. Persuasive effects of message framing and narrative format on promoting COVID-19 vaccination: a study on Chinese college students. Int J Environ Res Public Health 2021;18:9485. 10.3390/ijerph18189485
    1. Borah P. Message framing and COVID-19 vaccination intention: moderating roles of partisan media use and pre-attitudes about vaccination. Curr Psychol 2022:1-10. 10.1007/s12144-022-02851-3
    1. Dai H, Saccardo S, Han MA, et al. . Behavioural nudges increase COVID-19 vaccinations. Nature 2021;597:404–9. 10.1038/s41586-021-03843-2
    1. Freeman D, Loe BS, Yu L-M, et al. . Effects of different types of written vaccination information on COVID-19 vaccine hesitancy in the UK (OCEANS-III): a single-blind, parallel-group, randomised controlled trial. Lancet Public Health 2021;6:416–27. 10.1016/S2468-2667(21)00096-7
    1. Sinclair S, Agerström J, Sinclair S. Do social norms influence young people's willingness to take the COVID-19 vaccine? Health Commun 2021:1–8. 10.1080/10410236.2021.1937832
    1. Kachurka R, Krawczyk M, Rachubik J. Persuasive messages will not increase COVID-19 vaccine acceptance: evidence from a nationwide online experiment. Vaccines 2021;9:1113–13. 10.3390/vaccines9101113
    1. Santos HC, Goren A, Chabris CF, et al. . Effect of targeted behavioral science messages on COVID-19 vaccination registration among employees of a large health system: a randomized trial. JAMA Netw Open 2021;4:2–5. 10.1001/jamanetworkopen.2021.18702
    1. Barnes K, Colagiuri B. Positive attribute framing increases COVID-19 booster vaccine intention for unfamiliar vaccines. Vaccines 2022;10:962. 10.3390/vaccines10060962
    1. Levin IP, Schneider SL, Gaeth GJ. All frames are not created equal: a typology and critical analysis of framing effects. Organ Behav Hum Decis Process 1998;76:149–88. 10.1006/obhd.1998.2804
    1. Krishnamurthy P, Carter P, Blair E. Attribute framing and goal framing effects in health decisions. Organ Behav Hum Decis Process 2001;85:382–99. 10.1006/obhd.2001.2962
    1. Kuvaas B, Selart M. Effects of attribute framing on cognitive processing and evaluation. Organ Behav Hum Decis Process 2004;95:198–207. 10.1016/j.obhdp.2004.08.001
    1. Bigman CA, Cappella JN, Hornik RC. Effective or ineffective: attribute framing and the human papillomavirus (HPV) vaccine. Patient Educ Couns 2010;81 Suppl:S70–6. 10.1016/j.pec.2010.08.014
    1. Akl EA, Oxman AD, Herrin J, et al. . Framing of health information messages. Cochrane Database Syst Rev 2011;(12):CD00677710.1002/14651858.CD006777.pub2
    1. Tversky A, Kahneman D. The framing of decisions and the psychology of choice. Science 1981;211:453–8. 10.1126/science.7455683
    1. Cialdini RB, Kallgren CA, Reno RR. A focus theory of normative conduct: a theoretical refinement and reevaluation of the role of norms in human behavior. Adv Exp Soc Psychol 1991;24:201–34. 10.1016/S0065-2601(08)60330-5
    1. Van Woensel L. A bias radar for responsible policy-making. Springer Nature, 2020. ISBN: 978-3-030-32126-0. 10.1007/978-3-030-32126-0
    1. van der Linden SL, Clarke CE, Maibach EW. Highlighting consensus among medical scientists increases public support for vaccines: evidence from a randomized experiment. BMC Public Health 2015;15:1207:1–5. 10.1186/s12889-015-2541-4
    1. Nam Y, Park HG, Kim Y-H. Do you favor positive information or dislike negative information? cultural variations in the derivation of the framing effect. Curr Psychol 2021;28. 10.1007/s12144-020-01234-w
    1. Cheon JE, Nam Y, Kim KJ, et al. . Cultural variability in the attribute framing effect. Front Psychol 2021;12:754265. 10.3389/fpsyg.2021.754265
    1. Pattison AB, Reinfelde M, Chang H, et al. . Finding the facts in an infodemic: framing effective COVID-19 messages to connect people to authoritative content. BMJ Glob Health 2022;7:e007582. 10.1136/bmjgh-2021-007582
    1. Kasting ML, Head KJ, Cox D, et al. . The effects of message framing and healthcare provider recommendation on adult hepatitis B vaccination: a randomized controlled trial. Prev Med 2019;127:105798. 10.1016/j.ypmed.2019.105798
    1. Nyhan B, Reifler J, Richey S, et al. . Effective messages in vaccine promotion: a randomized trial. Pediatrics 2014;133:e835–42. 10.1542/peds.2013-2365
    1. Kumari A, Ranjan P, Chopra S, et al. . Knowledge, barriers and facilitators regarding COVID-19 vaccine and vaccination programme among the general population: a cross-sectional survey from one thousand two hundred and forty-nine participants. Diabetes Metab Syndr 2021;15:987–92. 10.1016/j.dsx.2021.04.015
    1. Ratcliff CL, Jensen JD, Scherr CL, et al. . Loss/Gain framing, dose, and Reactance: a message experiment. Risk Anal 2019;39:2640–52. 10.1111/risa.13379
    1. Ahmad R, Pfordten D, Koh W. INTERACTIVE: How is Malaysia’s Covid-19 vaccination plan progressing? Find out here. The Star, 2021. Available: [Accessed 3 Feb 2022].
    1. JFW L, Woon YL, Leong CT, et al. . Factors influencing acceptance of the COVID-19 vaccine in Malaysia : a web-based survey. Osong Public Heal Res Perspect 2021;12:361–73. 10.24171/j.phrp.2021.0085
    1. Teh HS, Woon YL, Leong CT, et al. . Malaysian public preferences and decision making for COVID-19 vaccination: a discrete choice experiment. SSRN 2022:1–20. 10.2139/ssrn.4057234
    1. Loomba S, de Figueiredo A, Piatek SJ, et al. . Author correction: measuring the impact of COVID-19 vaccine misinformation on vaccination intent in the UK and USA. Nat Hum Behav 2021;5:960–14. 10.1038/s41562-021-01172-y
    1. Anderson ML. Multiple inference and gender differences in the effects of early intervention: a reevaluation of the Abecedarian, Perry preschool, and early training projects. J Am Stat Assoc 2008;103:1481–95. 10.1198/016214508000000841
    1. Department of Statistics Malaysia . Current population estimates, Malaysia, 2020, 2020.
    1. Household Income & Basic Amenities Survey Report 2019. Department of Statistics, Malaysia, 2020. Available: [Accessed 27 Feb 2021].
    1. Bonami B, Muchena C, Rogobete E, et al. . COVID-19 youth survey: report. Global Shapers community, IFMSA, HILA alliance; 2020. Available: [Accessed 5 Dec 2021].
    1. Centers for Disease Control and Prevention . Risk for COVID-19 Infection, Hospitalization, and Death By Age Group, 2022. Available: [Accessed 20 Feb 2022].
    1. Mohamed NA, Solehan HM, Mohd Rani MD, et al. . Knowledge, acceptance and perception on COVID-19 vaccine among Malaysians: a web-based survey. PLoS One 2021;16:e0256110–7. 10.1371/journal.pone.0256110
    1. Ashworth M, Thunström L, Cherry TL, et al. . Emphasize personal health benefits to boost COVID-19 vaccination rates. Proc Natl Acad Sci U S A 2021;118:1–3. 10.1073/pnas.2108225118
    1. Civis Analytics . The remaining mile : How do you persuade uncertain Americans to get vaccinated against COVID-19 ? 2021. Available: [Accessed 10 Mar 2022].
    1. Diament SM, Kaya A, Magenheim EB. Frames that matter: increasing the willingness to get the Covid-19 vaccines. Soc Sci Med 2022;292:1–10. 10.1016/j.socscimed.2021.114562
    1. Reyna VF, Broniatowski DA, Edelson SM. Viruses, vaccines, and COVID-19: explaining and improving risky decision-making. J Appl Res Mem Cogn 2021;10:491–509. 10.1016/j.jarmac.2021.08.004
    1. Lazarević LB, Purić D, et al. . What drives us to be (ir)responsible for our health during the COVID-19 pandemic? The role of personality, thinking styles, and conspiracy mentality. Pers Individ Dif 2020;176:1–7. 10.1016/j.paid.2021.110771
    1. Lindeman M, Svedholm-Häkkinen AM, Riekki TJJ. Searching for the cognitive basis of anti-vaccination attitudes. Think Reason 2022;11:1–26. 10.1080/13546783.2022.2046158
    1. Elling JM, De Vries H. Influence of Animation- versus Text-Based delivery of a web-based Computer-Tailored smoking cessation intervention on user perceptions. EJHC 2021;2:1–23. 10.47368/ejhc.2021.301
    1. Jensen UT, Ayers S, Koskan AM. Video-based messages to reduce COVID-19 vaccine hesitancy and nudge vaccination intentions. PLoS One 2022;17:e0265736. 10.1371/journal.pone.0265736
    1. Sumari M, Baharudin DF, Khalid NM, et al. . Family functioning in a Collectivist culture of Malaysia: a qualitative study. The Family Journal 2020;28:396–402. 10.1177/1066480719844334
    1. Helfinstein SM, Mumford JA, Poldrack RA. If all your friends jumped off a bridge: the effect of others' actions on engagement in and recommendation of risky behaviors. J Exp Psychol Gen 2015;144:12–17. 10.1037/xge0000043
    1. Schmid KL, Rivers SE, Latimer AE, et al. . Targeting or tailoring? maximizing resources to create effective health communications. Mark Health Serv 2008;28:32–7.
    1. Zainul E. PM: Malaysia to meet target of vaccinating 80% of population by 1Q22. The Edge Markets, 2021. Available: [Accessed 5 Jan 2022].
    1. Ferguson E, Gallagher L. Message framing with respect to decisions about vaccination: the roles of frame valence, frame method and perceived risk. Br J Psychol 2007;98:667–80. 10.1348/000712607X190692
    1. Loo K-Y, Letchumanan V. COVID-19: Malaysia’s fight against this deadly virus. Prog Micobes Mol Biol 2021;4:1–11. 10.36877/pmmb.a0000204
    1. Malaysia approves Sinovac, AstraZeneca COVID-19 vaccines for use. Channel News Asia, 2021. Available: [Accessed 28 Dec 2021].
    1. Leong LM, McKenzie CRM, Sher S, et al. . The role of inference in attribute framing effects. J Behav Decis Mak 2017;30:1147–56. 10.1002/bdm.2030
    1. O'Connor AM, Pennie RA, Dales RE. Framing effects on expectations, decisions, and side effects experienced: the case of influenza immunization. J Clin Epidemiol 1996;49:1271–6. 10.1016/s0895-4356(96)00177-1
    1. Enticott J, Gill JS, Bacon SL, et al. . Attitudes towards vaccines and intention to vaccinate against COVID- 19: a cross- sectional analysis— implications for public health communications in Australia. BMJ Open 2021;12:1–13. 10.1136/bmjopen-2021-057127
    1. Nguyen KH, Yankey D, Lu P-J, et al. . Report of Health Care Provider Recommendation for COVID-19 Vaccination Among Adults, by Recipient COVID-19 Vaccination Status and Attitudes - United States, April-September 2021. MMWR Morb Mortal Wkly Rep 2021;70:1723–30. 10.15585/mmwr.mm7050a1
    1. McKernan B, Saraçoğlu G. Covid ‘vaccination persuasion’ teams reap rewards in Turkey, 2021. The Guardian. Available: [Accessed 3 Feb 2022].
    1. Honora A, Wang K-Y, Chih W-H. How does information overload about COVID-19 vaccines influence individuals’ vaccination intentions? The roles of cyberchondria, perceived risk, and vaccine skepticism. Comput Human Behav 2022;130:107176–13. 10.1016/j.chb.2021.107176
    1. Habib R, White K, Hoegg J. Everybody thinks we should but Nobody does: how combined Injunctive and descriptive norms Motivate organ donor registration. J Consum Psychol 2021;31:621–30. 10.1002/jcpy.1220
    1. Sanyaolu A, Okorie C, Marinkovic A, et al. . Comorbidity and its impact on patients with COVID-19. SN Compr Clin Med 2020;2:1069–76. 10.1007/s42399-020-00363-4
    1. Bonem EM, Ellsworth PC, Gonzalez R. Age differences in risk: perceptions, intentions and domains. J Behav Decis Mak 2015;28:317–30. 10.1002/bdm.1848
    1. Alsharawy A, Spoon R, Smith A, et al. . Gender differences in fear and risk perception during the COVID-19 pandemic. Front Psychol 2021;12:1–9. 10.3389/fpsyg.2021.689467
    1. Lewis A, Duch R. Gender differences in perceived risk of COVID-19. Soc Sci Q 2021;102:2124–33. 10.1111/ssqu.13079
    1. Zintel S, Flock C, Arbogast AL, et al. . Gender differences in the intention to get vaccinated against COVID-19: a systematic review and meta-analysis. Z Gesundh Wiss 2022:1-25. 10.1007/s10389-021-01677-w
    1. Robins RW, Trzesniewski KH, Tracy JL, et al. . Global self-esteem across the life span. Psychol Aging 2002;17:423–34.
    1. Ogihara Y, Kusumi T. The developmental trajectory of self-esteem across the life span in Japan: age differences in scores on the Rosenberg self-esteem scale from adolescence to old age. Front Public Health 2020;8:1–18. 10.3389/fpubh.2020.00132
    1. Charness G, Gneezy U. Strong evidence for gender differences in risk taking. J Econ Behav Organ 2012;83:50–8. 10.1016/j.jebo.2011.06.007
    1. Gerosa T, Gui M, Hargittai E, et al. . (Mis)informed During COVID-19 : How Education Level and Information Sources Contribute to Knowledge Gaps. Int J Commun 2021;15:2196–217.
    1. Rattay P, Michalski N, Domanska OM, et al. . Differences in risk perception, knowledge and protective behaviour regarding COVID-19 by education level among women and men in Germany. results from the COVID-19 snapshot monitoring (COSMO) study. PLoS One 2021;16:e0251694–26. 10.1371/journal.pone.0251694
    1. Lehmann BA, Ruiter RAC, Chapman G, et al. . The intention to get vaccinated against influenza and actual vaccination uptake of Dutch healthcare personnel. Vaccine 2014;32:6986–91. 10.1016/j.vaccine.2014.10.034
    1. Ye L, Fang T, Cui J, et al. . The intentions to get vaccinated against influenza and actual vaccine uptake among diabetic patients in Ningbo, China: identifying motivators and barriers. Hum Vaccin Immunother 2021;17:106–18. 10.1080/21645515.2020.1761201
    1. Lim I. Khairy: Malaysia can use Pfizer’s Covid-19 vaccine now as conditional registration granted. Malay Mail, 2021. Available: [Accessed 16 Mar 2022].
    1. Kyriakidis NC, López-Cortés A, González EV, et al. . SARS-CoV-2 vaccines strategies: a comprehensive review of phase 3 candidates. NPJ Vaccines 2021;6:28. 10.1038/s41541-021-00292-w
    1. Johns Hopkins Coronavirus Resource Center . Vaccines. Johns Hopkins University, 2021. Available: [Accessed 2 Mar 2021].
    1. Harun HN, Arumugam T. Covid-19: PM, Health DG receive vaccine. New Straits Times, 2021. Available: [Accessed 2 Apr 2021].
    1. Covid-19 vaccination: 90% of healthcare personnel got first dose, says Khairy. The Star, 2021. Available: [Accessed 1 Apr 2021].
    1. Health minister: 3.5pc vaccine recipients experience mild to serious side effects. Malay Mail, 2021. Available: [Accessed 6 Apr 2021].
    1. Kaos JJ. Health Ministry confirms that nurse’s death not related to Covid-19 vaccine. The Star, 2021. Available: [Accessed 2 Apr 2021].
    1. CovidNow . COVID-19 deaths in Malaysia, 2022. Available: [Accessed 23 Apr 2021].
    1. Torjesen I. Covid-19: risk of cerebral blood clots from disease is 10 times that from vaccination, study finds. BMJ 2021;373:n1005. 10.1136/bmj.n1005
    1. Malas MB, Naazie IN, Elsayed N, et al. . Thromboembolism risk of COVID-19 is high and associated with a higher risk of mortality: a systematic review and meta-analysis. EClinicalMedicine 2020;29:100639. 10.1016/j.eclinm.2020.100639

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