Tab. I.
Main characteristics of the included studies.
| Author, year | Study period | Country | Study design | Administration channel | Sample size | Type of vaccine | Type of questions | Validation | Immunization behaviour |
|---|---|---|---|---|---|---|---|---|---|
| Adler A, 2007 | 2007 | Israel | Cross-sectional | Paper-based | 1,474 | Varicella | Closed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Adorador A, 2011 | 2011 | USA | Cross-sectional | Paper-based | 108 | Dtp | Closed | Not | Hesitancy/scepticism/doubt |
| Aharony N, 2017 | 2017 | Israel | Cross-sectional | On-line | 200 | Child vaccines | Likert scale | With statistical methods | Refusal |
| Akis S, 2011 | 2011 | Turkey | Cross-sectional | Paper-based | 611 | Flu | Closed | Not | Acceptance |
| Akmatov MK, 2009 | 2009 | Kyrgyzstan | Cross-sectional | Paper-based | 934 | Child vaccines | Closed | Not | Acceptance |
| Alberts CJ, 2017 | 2017 | Netherlands | Cross-sectional | 1,309 | Hpv | Closed | Statistical methods not reported | Acceptance | |
| Alfredsson R, 2004 | 2004 | Sweden | Cross-sectional | Paper-based | 300 | Mmr | Closed | With statistical methods | Acceptance |
| Allen JD, 2010 | 2010 | USA | Cross-sectional | On-line | 476 | Hpv | Closed | Not | Acceptance |
| Allison MA, 2010 | 2010 | USA | Cross-sectional | Paper-based | 259 | Flu | Likert scale | With statistical methods | Hesitancy/scepticism/doubt |
| Allred NJ, 2005 | 2005 | USA | Cross-sectional | 7,810 | Dt | Closed | With statistical methods | Acceptance | |
| Alshammari TM, 2018 | 2018 | Saudi Arabia | Cross-sectional | Paper-based | 467 | Child vaccines | Closed | Statistical methods not reported | Acceptance |
| Ambe JP, 2001 | 2001 | Nigeria | Cross-sectional | Paper-based | 500 | Measles | Closed | Statistical methods not reported | Refusal |
| Aharon AA, 2017 | 2017 | Israel | Cross-sectional | Paper-based | 731 | Hbv/dtp/mmr | Likert scale | Not | Refusal |
| Arrossi S, 2012 | 2012 | Argentina | Cross-sectional | Paper-based | 1,200 | Hpv | Closed | With statistical methods | Acceptance |
| Azizi FSM, 2017 | 2017 | Malesya | Cross-sectional | Paper-based | 545 | Child vaccines | Closed | With statistical methods | Hesitancy/scepticism/doubt |
| Baglioni A, 2014 | 2014 | Italy | Cross-sectional | Paper-based | 648 | Hpv | Closed | With statistical methods | Acceptance |
| Bakhache P, 2013 | 2013 | Multinational | Cross-sectional | On-line | 2,460 | Menb | Closed | Statistical methods not reported | Acceptance |
| Baldwin AS, 2013 | 2008-2010 | USA | Cross-sectional | Paper-based | 256 | Hpv | Likert scale | With statistical methods | Acceptance |
| Bardenheier B, 2003 | 2000 | USA | Cross-sectional | Paper-based | 648 | Hav | Closed | Not | Acceptance |
| Bardenheier B, 2004 | 2001 | USA | Case-control | Paper-based | 3,586 | Mmr/dtp/hbv | Likert scale | Not | Acceptance |
| Bardenheier BH, 2004 | 1997-1998 | USA | Cross-sectional | Paper-based | 3,552 | Dtp/hib/hbv/polio | Closed | Not | Hesitancy/scepticism/doubt |
| Barnack JL, 2010 | 2006 | USA | Cross-sectional | 200 | Hpv | Likert scale | Not | Acceptance | |
| Barnack-Tavlaris JL, 2016 | 2009 | USA | Cross-sectional | Telephone | 4,666 | Hpv | Closed | Not | Acceptance |
| Bazzano A, 2012 | 2007 | USA | Cross-sectional | Telephone | 197 | Child vaccines | Closed | With statistical methods | Hesitancy/scepticism/doubt |
| Bedford H, 2007 | 2004 | UK | Cross-sectional | Paper-based | 859 | New vaccines | Likert scale | Not | Acceptance |
| Beel ER, 2013 | 2010-2012 | USA | Cross-sectional | Paper-based | 511 | Child vaccines | Closed | With statistical methods | Acceptance |
| Ben Natan M, 2011 | 2008 | Israel | Cross-sectional | Paper-based | 103 | Hpv | Likert scale | With statistical methods | Hesitancy/scepticism/doubt |
| Ben Natan M, 2016 | 2015 | Israel | Cross-sectional | Paper-based | 200 | Flu | Likert scale | With statistical methods | Acceptance |
| Ben Natan M, 2017 | 2016 | Israel | Cross-sectional | Paper-based | 200 | Hpv | Likert scale | With statistical methods | Acceptance |
| Berenson AB, 2014 | 2011-2013 | USA | Cross-sectional | Paper-based | 1,256 | Hpv | Closed | With statistical methods | Acceptance |
| Bettinger JA, 2016 | 2011 | Canada | Cross-sectional | 34 | Flu | Closed | Not | Acceptance | |
| Bham SQ, 2016 | 2015 | Pakistan | Cross-sectional | Paper-based | 210 | Polio | Closed | Not | Acceptance |
| Bianco A, 2014 | 2014 | Italy | Cross-sectional | Paper-based | 566 | Hpv | Likert scale | Not | Acceptance |
| Bigham M, 2006 | 2002-2003 | Canada | Cross-sectional | Telephone | 487 | Hbv | Likert scale | With statistical methods | Hesitancy/scepticism/doubt |
| Alder S, 2015 | 2012 | Argentina | Cross-sectional | Paper-based | 180 | Hpv | Closed | With statistical methods | Acceptance |
| Basu P, 2011 | 2008 | India | Cross-sectional | Paper-based | 522 | Hpv | Closed | Statistical methods not reported | Acceptance |
| Blair A, 1997 | 1997 | Australia | Cross-sectional | Paper-based | 245 | Child vaccines | Open field | Not | Acceptance |
| Blyth CC, 2014 | 2008–2012 | Australia | Cross-sectional | Paper-based | 2,576 | Dtp/hib/hbv | Closed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Bodson J, 2016 | 2013 | USA | Cross-sectional | Paper-based | 119 | Hpv | Closed | With statistical methods | Hesitancy/scepticism/doubt |
| Bonanni P, 2001 | 2001 | Italy | Cross-sectional | Paper-based | 300 | Child vaccines | Closed | Not | Acceptance |
| Borena W, 2016 | 2015 | Austria | Cross-sectional | 439 | Hpv | Closed | Not | Hesitancy/scepticism/doubt | |
| Borras E, 2009 | 2003-2004 | Spain | Cross-sectional | Telephone | 630 | Child vaccines | Closed | Not | Hesitancy/scepticism/doubt |
| Brabin L, 2006 | 2005 | UK | Cross-sectional | 317 | Hpv | Mixed | With statistical methods | Hesitancy/scepticism/doubt | |
| Brambleby P, 1989 | 1988 | UK | Cross-sectional | 977 | Mmr | Mixed | Statistical methods not reported | Refusal | |
| Breitkopf CR, 2009 | 2007 | Vietnam | Cross-sectional | Paper-based | 139 | Hpv | Closed | Not | Hesitancy/scepticism/doubt |
| Brieger D, 2017 | N.A. | Australia | Cross-sectional | Paper-based | 201 | Mmr | Mixed | Not | Hesitancy/scepticism/doubt |
| Brown B, 2017 | 2015-2016 | USA | Cross-sectional | Paper-based | 200 | Hpv | Closed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Brown KF, 2011 | 2009 | UK | Cross-sectional | 535 | Mmr | Mixed | Statistical methods not reported | Hesitancy/scepticism/doubt | |
| Brunson EK, 2013 | 2010 | USA | Cross-sectional | On-line | 196 | Child vaccines | Mixed | With statistical methods | Hesitancy/scepticism/doubt |
| Bults M, 2011 | 2009-2010 | Netherlands | Cross-sectional | Face to face/mail | 1900 | Flu | Open field | With statistical methods | Refusal |
| Burdette AM, 2014 | 2014 | USA | Cross-sectional | Telephone | 20,000 | Hpv | Closed | With statistical methods | Refusal |
| Busse JW, 2011 | 2010 | Canada | Cross-sectional | Paper-based | 95 | Child vaccines | Closed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Buyuktiryaki B, 2014 | 2010 | Turkey | Cross-sectional | Paper-based | 625 | Flu | Likert scale | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Cacciatore MA, 2016 | 2014-2015 | USA | Cross-sectional | On-line | 2,000 | Measles | Mixed | Not | Hesitancy/scepticism/doubt |
| Campbell H, 2017 | 2015 | UK | Cross-sectional | Face to face | 1,792 | Child vaccines | Mixed | Not | Hesitancy/scepticism/doubt |
| Carlos RC, 2011 | N.A. | USA | Cross-sectional | 937 | Hpv | Mixed | Not | Hesitancy/scepticism/doubt | |
| Casiday R, 2006 | 2004 | UK | Cross-sectional | 996 | Mmr | Likert scale | Statistical methods not reported | Hesitancy/scepticism/doubt | |
| Cassell JA, 2006 | 2004 | Uk | Cross-sectional | 452 | Mmr | Mixed | Statistical methods not reported | Hesitancy/scepticism/doubt | |
| Cataldi JR, 2016 | 2015 | USA | Cross-sectional | On-line | 343 | Mmr | Mixed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Chan JY, 2014 | 2012 | Hong Kong | Cross-sectional | Paper-based | 1,285 | Varicella | Mixed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Chaparro RM, 2016 | 2012 | Argentina | Cross-sectional | Paper-based | 77 | Hpv | Likert scale | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Chau JPC, 2017 | 2013 | Hong Kong | Cross-sectional | Paper-based | 623 | Flu | Likert scale | With statistical methods | Hesitancy/scepticism/doubt |
| Chen CH, 2015 | 2011 | Taiwan | Cross-sectional | 1,300 | Flu | Likert scale | With statistical methods | Hesitancy/scepticism/doubt | |
| Chen MF, 2011 | 2009 | Taiwan | Cross-sectional | Paper-based | 2,778 | Flu | Mixed | With statistical methods | Hesitancy/scepticism/doubt |
| Cheruvu VK, 2017 | 2017 | USA | Cross-sectional | Telephone | 21,467 | Hpv | Closed | Not | Refusal |
| Chung YM, 2017 | 2012-2014 | USA | Cross-sectional | On-line | 5,121 | Child vaccines | Mixed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Cipriano JJ, 2018 | 2016 | USA | Cross-sectional | On-line | 75 | Hpv | Mixed | Not | Acceptance |
| Clark SJ, 2016 | 2012 | USA | Cross-sectional | On-line | 1,799 | Hpv | Mixed | With statistical methods | Acceptance |
| Clark SJ, 2016 | 2012 | USA | Cross-sectional | On-line | 1,799 | Hpv | Mixed | Not | Hesitancy/scepticism/doubt |
| Clark SJ, 2016 | 2013 | USA | Cross-sectional | On-line | 1,799 | Hpv | Mixed | Not | Hesitancy/scepticism/doubt |
| Cockcroft A, 2014 | 2011 | Nigeria | Cross-sectional | Paper-based | 5,257 | Measles | Closed | Not | Acceptance |
| Colon-Lopez V, 2016 | 2013 | Puerto Rico | Cross-sectional | Paper-based | 200 | Hpv | Mixed | Not | Acceptance |
| Colon-Lopez V, 2015 | 2013 | Puerto Rico | Cross-sectional | Paper-based | 200 | Hpv | Mixed | Not | Acceptance |
| Coniglio MA,2011 | 2008 | Italy | Cross-sectional | Paper-based | 1,500 | Child vaccines | Closed | Not | Hesitancy/scepticism/doubt |
| Constantine NA, 2007 | 2006 | USA | Cross-sectional | Telephone | 802 | Hpv | Mixed | Not | Acceptance |
| Cooper Robbins SC, 2011 | 2007 | Australia | Cross-sectional | Paper-based | 169 | Flu | Mixed | Not | Acceptance |
| Costa-Pinto JC, 2017 | 2014-2015 | Australia | Cross-sectional | On-line | 612 | Child vaccines | Mixed | Not | Acceptance |
| Coyne-Beasley T, 2013 | 2008 | USA | Cross-sectional | Telephone | 1281 | Mcv | Mixed | Not | Acceptance |
| Cuninghame CJ, 1994 | 1991-1992 | UK | Cross-sectional | Face to face/telephone/mail | 93 | Child vaccines | Mixed | Not | Acceptance |
| Cunningham-Erves J, 2016 | 2012-2013 | USA | Cross-sectional | Paper-based | 242 | Hpv | Likert scale | Not | Acceptance |
| Dahlstrom LA, 2010 | 2007 | Sweden | Cross-sectional | Web /paper based | 13,946 | Hpv | N.A. | With statistical methods | Acceptance |
| Daley MF, 2007 | 2003 | USA | Cross-sectional | Telephone | 472 | Flu | Mixed | Not | Acceptance |
| Danchin MH, 2017 | 2015-2016 | Australia | Cross-sectional | Questionnaire (ipad), follow-up phone surveys | 975 | Child vaccines | Mixed | Not | Acceptance |
| Danis K, 2010 | 2004–2005 | Greece | Cross-sectional | Paper-based | 3,434 | Child vaccines | Mixed | Not | Acceptance |
| Dannetun E, 2007 | 2005 | Sweden | Cross-sectional | Paper-based and online | 1,229 | Hbv | Mixed | Statistical methods not reported | Acceptance |
| Dannetun E, 2005 | 2003 | Sweden | Cross-sectional | Paper-based | 173 | Mmr | Mixed | Not | Refusal |
| Danova J, 2015 | 2013-2014 | Repubblica Ceca | Cross-sectional | Paper-based | 480 | Child vaccines | Closed | Not | Refusal |
| Darden PM, 2013 | 2008–2010 | USA | Cross-sectional | Telephone | Dtp/mcv/hpv | N.A. | Not | Refusal | |
| Davis K, 2004 | 2003 | USA | Cross-sectional | Paper-based | 575 | Hpv | Mixed | Not | Acceptance |
| Dawar M, 2002 | 1999 | Canada | Cross-sectional | Telephone | 191 | Hbv/dtp/hib | Mixed | Not | Acceptance |
| de Courval FP, 2003 | 2000 | Canada | Cross-sectional | Telephone | 663 | Varicella | Mixed | Not | Refusal |
| de Visser R, 2008 | 2008 | UK | Cross-sectional | Paper-based | 353 | Hpv | Likert scale | Not | Acceptance |
| Dempsey AF, 2011 | N.A. | USA | Cross-sectional | 830 | Hpv | Mixed | Not | Acceptance | |
| Dempsey AF, 2015 | 2012-2013 | USA | Cross-sectional | On-line | 54 | Hpv | Mixed | Not | Acceptance |
| Dempsey AF, 2006 | 2009 | USA | Cross-sectional | On-line | 1,178 | Hpv | Likert scale | Not | Acceptance |
| DiAnna Kinder F, 2017 | N.A. | USA | Cross-sectional | Paper-based | 72 | Hpv | Mixed | Not | Refusal |
| Dinh TA, 2007 | 2005 | Vietnam | Cross-sectional | Paper-based | 181 | Hpv | Likert scale | Statistical methods not reported | Acceptance |
| Dorell C, 2014 | 2010 | USA | Cross-sectional | Telephone | 4103 | Hpv | Closed | Not | Hesitancy/scepticism/doubt |
| Dorell C, 2013 | 2010-2011 | USA | Cross-sectional | Telephone | 8,652 | Hpv/dtp/mcv | Closed | Not | Hesitancy/scepticism/doubt |
| Dorell C, 2011 | 2009-2010 | USA | Cross-sectional | Telephone | 20,066 | Hpv/mcv/dtp | Closed | Not | Hesitancy/scepticism/doubt |
| Dube E, 2012 | 2008-2009 | Canada | Cohort | Paper-based | 413 | Rotavirus | Mixed | Not | Acceptance |
| Dube E, 2015 | 2014 | Canada | Cross-sectional | Telephone | 703 | Menb | Likert scale | Statistical methods not reported | Acceptance |
| Dube E, 2017 | 2015 | Canada | Cross-sectional | On-line | 20,13 | Child vaccines | Mixed | Not | Acceptance |
| Dube E, 2016 | 2014 | Canada | Cross-sectional | Telephone | 589 | Child vaccines | Likert scale | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Ezat SW, 2013 | 2012 | Malesya | Cross-sectional | Not reported | 155 | Hpv | N.A. | Not | Acceptance |
| Ezeanochie MC, 2014 | 2009 | Nigeria | Cross-sectional | Paper-based | 201 | Hpv | Closed | Statistical methods not reported | Acceptance |
| Ezenwa BN, 2013 | 2012 | Nigeria | Cross-sectional | Paper-based | 290 | Hpv | N.A. | Not | Acceptance |
| Farias CC, 2016 | 2015 | Brazil | Cross-sectional | Paper-based | 797 | Hpv | Mixed | Not | Acceptance |
| Flood EM, 2010 | 2009 | USA | Cross-sectional | On-line | 500 | Flu | Likert scale | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Flynn M, 2004 | 1999-2000 | UK | Cohort | Paper-based | 511 | Mmr | Likert scale | Not | Hesitancy/scepticism/doubt |
| Freed GL, 2010 | 2009 | USA | Cross-sectional | On-line | 1,552 | Mmr/varicella/mcv/hpv | N.A. | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Freeman VA, 1999 | 1995 | USA | Cross-sectional | 247 | Varicella | Closed | Not | Hesitancy/scepticism/doubt | |
| Frew PM, 2016 | 2012-2014 | USA | Cross-sectional | On-line | 5,121 | Child vaccines | Closed | Not | Acceptance |
| Frew PM, 2011 | 2009 | USA | Cross-sectional | Not reported | 223 | Flu | Likert scale | Not | Refusal |
| Fry AM, 2001 | 1999-2000 | USA | Case-control | Paper-based | 66 | Hib | Open field | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Fuchs EL, 2016 | 2011-2013 | USA | Cross-sectional | Not reported | 350 | Hpv | Likert scale | Not | Hesitancy/scepticism/doubt |
| Garcia DA, 2014 | 2000 | Colombia | Cross-sectional | Paper-based | 4,802 | Child vaccines | Mixed | Not | Hesitancy/scepticism/doubt |
| Gargano LM, 2013 | 2011 | USA | Cross-sectional | Telephone | 114 | Flu/dtp/mcv/hpv | Closed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Gaudino JA, 2012 | 2004-2005 | USA | Cross-sectional | On-line | 1,588 | Child vaccines | Likert scale | Not | Hesitancy/scepticism/doubt |
| Gefenaite G, 2012 | 2009 | Netherlands | Case-control | 469 | Hpv | Closed | Not | Hesitancy/scepticism/doubt | |
| Gellatly J, 2005 | 2003-2004 | UK | Cross-sectional | Paper-based | 110 | Mmr | Likert scale | Not | Hesitancy/scepticism/doubt |
| Gellin BG, 2000 | 1999 | USA | Cross-sectional | Telephone | 1,600 | Child vaccines | Likert scale | Not | Acceptance |
| Gentile A, 2015 | 2013 | Argentina | Cross-sectional | Not reported | 1,350 | Flu | Likert scale | Not | Hesitancy/scepticism/doubt |
| Gerend MA, 2009 | 2008 | USA | Cross-sectional | Paper-based | 82 | Hpv | Closed | Not | Acceptance |
| Gesser-Edelsburg A, 2016 | 2013 | Israel | Cross-sectional | On-line | 197 | Polio | Open field | Not | Refusal |
| Giambi C, 2014 | 2012 | Italy | Cross-sectional | 1,738 | Hpv | Mixed | Not | Refusal | |
| Gilbert NL, 2016 | 2013 | Canada | Cross-sectional | Telephone | 5,720 | Hpv | Likert scale | Not | Hesitancy/scepticism/doubt |
| Gilkey MB, 2017 | 2014-2015 | USA | Cross-sectional | On-line | 1,484 | Hpv | Closed | Not | Hesitancy/scepticism/doubt |
| Glanz JM, 2013 | 2009-2011 | USA | Cross-sectional | 854 | Child vaccines | Closed | Not | Hesitancy/scepticism/doubt | |
| Glenn BA, 2015 | 2009 | USA | Cross-sectional | Telephone | 444 | Hpv | Closed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Gomez Y, 2012 | 2010 | USA | Cross-sectional | Paper-based | 773 | Flu | N.A. | Not | Hesitancy/scepticism/doubt |
| Gottlieb SL, 2009 | 2007 | USA | Cross-sectional | Telephone | 889 | Hpv | Mixed | Not | Hesitancy/scepticism/doubt |
| Gowda C, 2013 | 2011 | USA | Cross-sectional | On-line | 79 | Mmr | Likert scale | Not | Hesitancy/scepticism/doubt |
| Grabiel M, 2013 | 2012 | USA | Cross-sectional | Paper-based | 129 | Hpv | Closed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Grandahl M, 2014 | 2012 | Sweden | Cross-sectional | Face to face | 25 | Hpv | Open field | Statistical methods not reported | Refusal |
| Grandahl M, 2017 | 2012 | Sweden | Cross-sectional | Paper-based | 200 | Hpv | Likert scale | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Greenberg J, 2017 | 2015 | Canada | Cross-sectional | On-line | 1,121 | Mmr | Likert scale | Statistical methods not reported | Acceptance |
| Greenfield LS, 2015 | 2012 | USA | Cross-sectional | Face to face | 157 | Dtp/mcv/hpv | Mixed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Griebeler M, 2012 | 2010 | USA | Cross-sectional | Paper-based | 102 | Hpv | Likert scale | Statistical methods not reported | Acceptance |
| Guerry SL, 2011 | 2007-2008 | USA | Cross-sectional | Telephone | 509 | Hpv | Likert scale | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Gundogdu Z, 2011 | 2009-2010 | Turkey | Cross-sectional | Paper-based | 300 | Varicella | Likert scale | With statistical methods | Acceptance |
| Gunduz S, 2014 | 2011-2012 | Turkey | Cross-sectional | Paper-based | 285 | Flu | Mixed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Gupta R, 2013 | 2009-2010 | USA | Cross-sectional | Paper-based and online | 381 | Flu | Closed | Not | Hesitancy/scepticism/doubt |
| Gust D, 2005 | 2002 | USA | Cross-sectional | 697 | Child vaccines | Likert scale | Statistical methods not reported | Hesitancy/scepticism/doubt | |
| Gust DA, 2006 | 2004-2005 | USA | Cross-sectional | Telephone | 2,286 | Mmr/dtp/hbv | Closed | Not | Hesitancy/scepticism/doubt |
| Gust DA, 2008 | 2003-2004 | USA | Cross-sectional | Telephone | 3,924 | Child vaccines | Closed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Gust DA, 2005 | 2003 | USA | Cross-sectional | 642 | Child vaccines | Likert scale | Statistical methods not reported | Hesitancy/scepticism/doubt | |
| Gust DA, 2004 | 2001 | USA | Case-control | 1,477 | Mmr/dtp/hbv | Likert scale | Statistical methods not reported | Hesitancy/scepticism/doubt | |
| Gust DA, 2003 | 2002 | USA | Cross-sectional | 1,768 | Child vaccines | Likert scale | Statistical methods not reported | Acceptance | |
| Gustafson R, 2005 | 2003 | Canada | Cross-sectional | Telephone | 1,246 | Varicella | Likert scale | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Haesebaert J, 2012 | 2008 | France | Cross-sectional | Face to face | 32 | Hpv | Open field | Statistical methods not reported | Acceptance |
| Hagan D, 2016 | 2013 | Ghana | Cross-sectional | Paper-based | 303 | Child vaccines | Closed | Statistical methods not reported | Acceptance |
| Hagemann C, 2017 | 2009-2011 | Germany | Cross-sectional | Paper-based | 1,998 | Varicella/measles | N.A. | With statistical methods | Hesitancy/scepticism/doubt |
| Hak E, 2005 | N.A. | Netherland | Cross-sectional | Not reported | 283 | Influenza/hbv/bcg | Likert scale | Not | Refusal |
| Hamama-Raz Y, 2016 | 2014 | Israel | Cross-sectional | On-line | 314 | Child vaccines | Likert scale | Not | Acceptance |
| Han K, Zheng H, 2014 | 2010 | China | Cross-sectional | Face to face | 1,530 | Bcg/dtp/polio/mcv/hbv | Closed | With statistical methods | Hesitancy/scepticism/doubt |
| Hanley SJ, 2012 | 2010 | Japan | Cross-sectional | Paper-based | 862 | Hpv | Likert scale | Not | Acceptance |
| Hanley SJ, 2014 | 2010 | Japan | Cross-sectional | Paper-based | 54 | Hpv | Likert scale | Not | Acceptance |
| Harmsen IA, 2012 | 2011 | Netherlands | Cross-sectional | Paper-based | 906 | Hbv | Likert scale | Not | Acceptance |
| He L, 2015 | 2013 | China | Cross-sectional | Face to face | 298 | Flu | Open field | Not | Hesitancy/scepticism/doubt |
| Healy CM, 2014 | N.A. | USA | Cross-sectional | Not reported | 401 | Hib/pcv/mcv/flu/hbv/hav/hpv/rotavirus | Closed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Henrikson NB, 2017 | 2013-2015 | USA | Cohort | Telephone | 237 | Child vaccines | Closed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Hertweck SP, 2013 | N.A. | USA | Cross-sectional | On-line | 68 | Hpv | Likert scale | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Hilyard KM, 2014 | 2010 | USA | Cross-sectional | Not reported | 684 | Flu | Closed | Not | Hesitancy/scepticism/doubt |
| Hofman R, 2014 | 2009-2011 | Netherlands | Cohort | 793 | Hpv | Likert scale | Statistical methods not reported | Hesitancy/scepticism/doubt | |
| Hofstetter AM, 2015 | 2011 | USA | Cross-sectional | Face to face | 128 | Flu | Closed | With statistical methods | Hesitancy/scepticism/doubt |
| Hon KL, 2016 | N.A. | Hong Kong | Cross-sectional | Paper-based | 3,479 | Flu | N.A. | Not | Hesitancy/scepticism/doubt |
| Hontelez JA, 2010 | N.A. | Netherland | Cross-sectional | Paper-based | 198 | Hbv | Likert scale | Not | Hesitancy/scepticism/doubt |
| Horn L, 2010 | 2008 | USA | Cross-sectional | Paper-based | 325 | Hpv | Likert scale | With statistical methods | Acceptance |
| How CH, 2016 | 2014 | Singapore | Cross-sectional | Face to face | 200 | Pcv | Likert scale | Not | Hesitancy/scepticism/doubt |
| Hu Y, 2017 | 2014 | China | Cross-sectional | Face to face | 2,772 | Child vaccines | N.A. | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Hwang JH, 2017 | 2014 | South Korea | Cross-sectional | Face to face | 638 | Flu | Closed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Ilter E, 2010 | 2009 | Turkey | Cross-sectional | Face to face | 525 | Hpv | Likert scale | Not | Hesitancy/scepticism/doubt |
| Imburgia TM, 2017 | 2014 | USA | Cross-sectional | On-line | 2,363 | Flu | Likert scale | Not | Hesitancy/scepticism/doubt |
| Impicciatore P, 2000 | 1997 | Italy | Cross-sectional | Face to face | 1,035 | Mmr | Closed | With statistical methods | Acceptance |
| Jani JV, 2008 | 2001 | Mozambique | Cross-sectional | Face to face | 668 | Child vaccines | N.A. | Statistical methods not reported | Acceptance |
| Jaspers L, 2011 | 2009 | Indonesia | Cross-sectional | Face to face | 746 | Hpv | Closed | Not | Acceptance |
| Jessop LJ, 2010 | 2001-2004 | UK | Cohort | Paper-based | 749 | Mmr | Closed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Jolley D, 2014 | 2012 | UK | Cross-sectional | On-line | 89 | Child vaccines | Likert scale | Statistical methods not reported | N.A. |
| Joseph NP, 2012 | 2008-2009 | USA | Cross-sectional | Face to face | 70 | Hpv | Open field | With statistical methods | Hesitancy/scepticism/doubt |
| Joseph NP, 2015 | N.A. | Cross-sectional | Paper-based | 55 | Hpv | Closed | With statistical methods | N.A. | |
| Jung M, 2013 | N.A. | Cross-sectional | On-line | 639 | Flu | N.A. | Not | Hesitancy/scepticism/doubt | |
| Kadis JA, 2011 | 2009 | USA | Cross-sectional | On-line | 496 | Hpv | Closed | Statistical methods not reported | Acceptance |
| Kahn JA, 2009 | 2006-2007 | USA | Cross-sectional | Paper-based | 7,207 | Hpv | Likert scale | With statistical methods | Hesitancy/scepticism/doubt |
| Kalucka SK, 2016 | N.A. | Poland | Cross-sectional | Paper-based | 140 | Child vaccines | Closed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Katz ML, 2012 | 2009 | USA | Cross-sectional | Paper-based | 111 | Hpv | Likert scale | Not | Hesitancy/scepticism/doubt |
| Haesebaert J, 2014 | 2008 | France | Cross-sectional | Paper-based | 99 | Hpv | Open field | With statistical methods | Hesitancy/scepticism/doubt |
| Kaya A, 2017 | 2016 | Turkey | Cross-sectional | Paper-based | 102 | Flu | Mixed | Not | Acceptance |
| Kelley CA, 2015 | N.A. | Case-control | Paper-based | 229 | Child vaccines | Mixed | Statistical methods not reported | Refusal | |
| Kempe A, 2007 | 2003 | USA | Cross-sectional | Telephone | 472 | Flu | Mixed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Kennedy A, 2011 | 2009 | USA | Cross-sectional | 475 | Child vaccines | Likert scale | Statistical methods not reported | Hesitancy/scepticism/doubt | |
| Kennedy A, 2011 | 2010 | USA | Cross-sectional | 376 | Child vaccines | Likert scale | Statistical methods not reported | Hesitancy/scepticism/doubt | |
| Kennedy AM, 2005 | 2002 | USA | Cross-sectional | 1527 | Child vaccines | Likert scale | Statistical methods not reported | Hesitancy/scepticism/doubt | |
| Kepka D, 2015 | 2013 | USA | Cross-sectional | Paper-based | 118 | Hpv | Closed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Kepka D, 2015 | 2013 | USA | Cross-sectional | Paper-based | 67 | Hpv | Mixed | With statistical methods | Hesitancy/scepticism/doubt |
| Kepka DL, 2012 | 2009 | USA | Cross-sectional | Paper-based | 578 | Hpv | Closed | With statistical methods | Hesitancy/scepticism/doubt |
| Kester LM, 2013 | 2010 | USA | Cross-sectional | On-line | 501 | Hpv | Mixed | Not | Hesitancy/scepticism/doubt |
| Kettunen C, 2017 | N.A. | USA | Cross-sectional | 84 | Child vaccines | Mixed | Statistical methods not reported | Acceptance | |
| Kim KM, 2017 | 2014-2015 | South Korea | Cross-sectional | Paper-based | 200 | Hpv | Mixed | Not | Acceptance |
| Kinder FD. 2016 | N.A. | USA | Cross-sectional | Paper-based | 72 | Hpv | Mixed | Not | Refusal |
| Ko HS, 2015 | N.A. | South Korea | Cross-sectional | Paper-based | 308 | Dtp | Closed | Not | Acceptance |
| Kong KA, 2014 | 2013 | South Korea | Cross-sectional | Telephone | 800 | Hav | Mixed | Statistical methods not reported | Acceptance |
| Krawczyk A, 2015 | 2010 | Canada | Cross-sectional | 774 | Hpv | Likert scale | Not | Hesitancy/scepticism/doubt | |
| Krawczyk A, 2015 | 2010 | Canada | Cross-sectional | 708 | Hpv | Open field | Not | Refusal | |
| Krieger JL, 2011 | N.A. | USA | Cross-sectional | Paper-based | 182 | Hpv | Closed | Not | Acceptance |
| Lavail KH, 2013 | 2010 | USA | Case-control | 376 | Child vaccines | Likert scale | Not | Acceptance | |
| Le Ngoc Tho S, 2015 | 2013 | France | Cross-sectional | Paper-based | 1,270 | Menb | Mixed | With statistical methods | Acceptance |
| Lechuga J, 2012 | N.A. | USA | Cross-sectional | Paper-based | 150 | Hpv | Open field | Not | Acceptance |
| Lee KN, 2017 | 2015-2016 | South Korea | Cross-sectional | Paper-based | 140 | Hpv | Mixed | Not | Acceptance |
| Lee Mortensen G, 2015 | 2013 | Multinational | Cross-sectional | Paper-based | 1,837 | Hpv | Closed | Not | Acceptance |
| Lehmann BA, 2017 | 2015 | Netherlands | Cross-sectional | Paper-based | 1,615 | Child vaccines | Mixed | Not | Acceptance |
| Lewis T, 1988 | 1988 | USA | Cohort | 2,029 | Dtp | N.A. | Not | N.A. | |
| Liao Q, 2016 | 2012-2013 | Hong Kong | Cross-sectional | Telephone | 1,226 | Flu | Mixed | Not | Acceptance |
| Lin CJ, 2006 | 2003-2004 | USA | Cross-sectional | Paper-based | 951 | Flu | Mixed | Not | Acceptance |
| Linam WM, 2014 | 2010-2011 | USA | Cross-sectional | Paper-based | 372 | Flu | Mixed | Not | Acceptance |
| Lindley MC, 2016 | 2013 | USA | Cross-sectional | 6,676 | Hpv | Mixed | Not | Acceptance | |
| Livni G, 2017 | 2012 | Israel | Cross-sectional | Paper-based | 186 | Flu | Mixed | Statistical methods not reported | Acceptance |
| Loke AY, 2017 | 2010 | Hong Kong | Cross-sectional | Paper-based | 170 | Hpv | Mixed | Not | Hesitancy/scepticism/doubt |
| Low MSF, 2017 | 2015-2016 | Singapore | Cross-sectional | On-line | 332 | Flu | Mixed | Statistical methods not reported | Acceptance |
| Luthy KE, 2010 | N.A. | USA | Cross-sectional | Paper-based | 86 | Child vaccines | Mixed | Not | Hesitancy/scepticism/doubt |
| Luthy KE, 2013 | N.A. | USA | Cross-sectional | Paper-based | 801 | Child vaccines | Mixed | Not | Hesitancy/scepticism/doubt |
| Luthy KE, 2009 | N.A. | USA | Cross-sectional | Paper-based | 86 | Child vaccines | Closed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Maayan-Metzger A, 2005 | 2003 | Israel | Case-control | Paper-based | 204 | Hbv | Closed | Not | Hesitancy/scepticism/doubt |
| MacDonald SE, 2014 | N.A. | Canada | Case-control | 444 | Child vaccines | Closed | Not | Hesitancy/scepticism/doubt | |
| MacDougall DM, 2016 | 2010-2012 | Canada | Case-control | Paper-based | 722 | Rotavirus | Mixed | Statistical methods not reported | Acceptance |
| Madhivanan P, 2014 | 2010 | India | Cross-sectional | 797 | Hpv | Likert scale | Not | Acceptance | |
| Mameli C, 2014 | 2013 | Italy | Cross-sectional | Paper-based | 1,842 | Menb | Closed | Not | Hesitancy/scepticism/doubt |
| Marlow LA, 2007 | 2006 | UK | Cross-sectional | Paper-based | 684 | Hpv | Mixed | Not | Acceptance |
| Marlow LA, 2007 | 2006 | UK | Cross-sectional | Paper-based | 684 | Hpv | Likert scale | With statistical methods | Acceptance |
| Marshall H, 2014 | 2012 | Australia | Cross-sectional | Paper-based | 966 | Menb | N.A. | With statistical methods | Acceptance |
| Marshall H, 2007 | 2006 | Australia | Cross-sectional | Telephone | 2,002 | Hpv | Closed | With statistical methods | Acceptance |
| Mayet AY, 2017 | 2013 | Saudi Arabia | Cross-sectional | Paper-based | 998 | Flu | Mixed | Not | Hesitancy/scepticism/doubt |
| McCauley MM, 2012 | 2010 | USA | Cross-sectional | Telephone | 690 | Child vaccines | Likert scale | Statistical methods not reported | N.A. |
| McHale P, 2016 | 2012-2013 | UK | Cross-sectional | Telephone | 47 | Mmr | Open field | Statistical methods not reported | N.A. |
| Melman ST, 1999 | 1995-1997 | USA | Cross-sectional | Paper-based | 1,059 | Child vaccines | Open field | Not | N.A. |
| Meszaros JR, 1996 | N.A. | USA | Cross-sectional | Paper-based | 294 | Pertussis | Mixed | Not | N.A. |
| Michael CA, 2014 | 2012 | Nigeria | Cross-sectional | Paper-based | 48 | Polio | Open field | Not | N.A. |
| Michael CE, 2014 | 2009 | Nigeria | Cross-sectional | Paper-based | 201 | Hpv | Closed | Not | Acceptance |
| Middleman AB, 2002 | 2000 | USA | Cross-sectional | Paper-based | 563 | Hbv | Closed | Not | Hesitancy/scepticism/doubt |
| Milteer RM, 1996 | 1991-1994 | USA | Cross-sectional | Paper-based | 175 | Child vaccines | Open field | Not | N.A. |
| Morales-Campos DY, 2017 | 2011-2013 | Cameron | Cross-sectional | Paper-based | 317 | Hpv | Mixed | Not | Hesitancy/scepticism/doubt |
| Morhason-Bello IO, 2015 | 2012 | Nigeria | Cross-sectional | Paper-based | 1,002 | Hpv | Likert scale | With statistical methods | Acceptance |
| Morrone T, 2017 | 2015 | Italy | Cross-sectional | Paper-based | 543 | Menb | N.A. | With statistical methods | N.A. |
| Moulsdale P, 2017 | 2014 | UK | Cross-sectional | Paper-based | 86 | Flu | Likert scale | Not | Acceptance |
| Muhwezi WW, 2014 | 2012 | Uganda | Cross-sectional | Paper-based | 870 | Hpv | Closed | With statistical methods | Acceptance |
| Murakami H, 2014 | 2007 | Pakistan | Cross-sectional | Paper-based | 630 | Polio | Open field | Not | Refusal |
| My C, 2017 | 2012 | Australia | Cross-sectional | On-line | 452 | Flu | Closed | Not | Hesitancy/scepticism/doubt |
| Naeem M, 2011 | 2010 | Pakistan | Cross-sectional | Paper-based | 548 | Polio | Closed | Not | Hesitancy/scepticism/doubt |
| Naeem M, 2011 | 2010 | Pakistan | Cross-sectional | Paper-based | 506 | Hbv | Closed | Not | Hesitancy/scepticism/doubt |
| Namuigi P, 2005 | 2003 | Papua New Guinea | Cross-sectional | Paper-based | 120 | Measles | Closed | Not | Hesitancy/scepticism/doubt |
| Niederhauser VP, 2007 | 2003-2004 | USA | Cross-sectional | Paper-based | 64 | Child vaccines | Open field | Not | Hesitancy/scepticism/doubt |
| Oladokun RE, 2010 | 2009 | Nigeria | Cross-sectional | Paper-based | 248 | Bcg/polio/dtp/masles/hbv | Closed | Statistical methods not reported | Acceptance |
| Onnela JP, 2016 | 2012 | India | Cohort | Paper-based | 2,462 | Polio | Closed | Statistical methods not reported | Acceptance |
| Oria PA, 2013 | 2010 | Kenya | Cross-sectional | Paper-based | 7,177 | Flu | Mixed | Not | N.A. |
| Ozawa S, 2017 | 2013 | Nigeria | Cross-sectional | Paper-based | 198 | Dtp/measles/polio | Closed | Statistical methods not reported | N.A. |
| Paek HJ, 2015 | 2014 | South Korea | Cross-sectional | Paper-based | 1,017 | Child vaccines | Mixed | Not | N.A. |
| Painter JE, 2011 | 2009 | USA | Cross-sectional | Paper-based | 102 | Flu | Mixed | Not | N.A. |
| Parrella A, 2013 | 2011 | Australia | Cross-sectional | Telephone | 469 | Child vaccines | Likert scale | Not | N.A. |
| Parrella A, 2012 | 2010 | New Zeland | Cross-sectional | Telephone | 179 | Dtp/polio/hbv/hib/rotavirus/mmrv/mcv/pcv/flu | Closed | Statistical methods not reported | N.A. |
| Paulussen TG, 2006 | 1999 | Netherland | Cross-sectional | On-line | 491 | Dtp/polio/hib/mmr | Closed | Not | N.A. |
| Peleg N, 2015 | 2011 | Israel | Cross-sectional | Paper-based | 273 | Flu | Closed | Statistical methods not reported | N.A. |
| Pelucchi C, 2010 | 2008 | Italy | Cross-sectional | Paper-based | 3,026 | Hpv | N.A. | Not | N.A. |
| Perez S, 2016 | N.A. | Canada | Cross-sectional | On-line | 2,272 | Hpv | Closed | Statistical methods not reported | N.A. |
| Perez S, 2017 | 2014 | Canada | Cross-sectional | On-line | 2,272 | Hpv | Closed | With statistical methods | N.A. |
| Perez S, 2016 | 2014 | Canada | Cross-sectional | On-line | 2,272 | Hpv | Closed | Statistical methods not reported | N.A. |
| Perez S, 2016 | 2014 | Canada | Cross-sectional | On-line | 2,272 | Hpv | Closed | Statistical methods not reported | N.A. |
| Podolsky R, 2009 | N.A. | Usa | Cross-sectional | Paper-based | 308 | Hpv | Mixed | Statistical methods not reported | N.A. |
| Pot M, 2017 | 2015-2016 | Netherlands | Cross-sectional | On-line | 8,062 | Hpv | Closed | Not | N.A. |
| Reiter PL, 2013 | 2008-2010 | Usa | Cross-sectional | 1,951 | Hpv | Mixed | Statistical methods not reported | N.A. | |
| Restivo V, 2015 | 2012-2013 | Italy | Cross-sectional | Telephone | 443 | Mmr | Closed | Not | N.A. |
| Roberts JR, 2015 | 2011-2012 | USA | Cross-sectional | Paper-based | 363 | Dtp/mcv/hpv | Closed | Statistical methods not reported | N.A. |
| Robitz R, 2011 | 2007-2008 | USA | Cross-sectional | Telephone | 484 | Hpv | Closed | Statistical methods not reported | N.A. |
| Rogers C, 2014 | N.A. | USA | Cross-sectional | On-line | 51 | Child vaccines | Closed | Not | N.A. |
| Ruffin MT, 2012 | 2006-2008 | USA | Case-control | Telephone | 1,131 | Hpv | Closed | Not | N.A. |
| Salmon DA, 2005 | 2002-2003 | USA | Case-control | 1,367 | Polio/mmrv/dtp/hib/hbv | Closed | Not | N.A. | |
| Salmon DA, 2009 | N.A. | USA | Case-control | 963 | Child vaccines | Closed | Not | N.A. | |
| Sam IC, 2009 | 2007 | Malaysia | Cross-sectional | Paper-based | 362 | Hpv | Mixed | Not | N.A. |
| Sampson R, 2011 | 2008 | UK | Cross-sectional | I part mail, ii part interview | 7 | Flu | Closed | Not | N.A. |
| Rickert VI, 2015 | 2012-2013 | USA | Cross-sectional | On-line | 501 | Child vaccines/flu/pcv/mmr/varicella/dtp/hav/hbv/hpv/mcv | Closed | Not | N.A. |
| Rose SB, 2012 | 2008-2009 | New Zeland | Cross-sectional | Paper-based | 769 | Hpv | Closed | Not | N.A. |
| Santibanez TA, 2016 | 2011-2012 | USA | Cross-sectional | Telephone | 19,178 | Flu | Closed | Not | Hesitancy/scepticism/doubt |
| Saqer A, 2017 | 2017 | Emirati Arabi | Cross-sectional | Paper-based | 400 | Hpv | Closed | With statistical methods | Hesitancy/scepticism/doubt |
| Schollin Ask L, 2017 | 2014 | Sweden | Cross-sectional | On-line | 1,063 | Rotavirus | Closed | With statistical methods | Hesitancy/scepticism/doubt |
| Schwarz NG, 2009 | 2009 | Gabon | Cross-sectional | Paper-based | 40 | Child vaccines | Closed | Statistical methods not reported | Acceptance |
| Selmouni F, 2015 | 2015 | Marocco | Cross-sectional | Paper-based | 1,312 | Hpv | Open field | Not | Acceptance |
| Sengupta B, 1998 | 1998 | India | Cross-sectional | Paper-based | 656 | Polio | Mixed | Not | Hesitancy/scepticism/doubt |
| Seven M, 2015 | 2015 | Turkey | Cross-sectional | Paper-based | 368 | Hpv | Closed | Not | N.A. |
| Shao SJ, 2015 | 2014 | Caraibi | Cross-sectional | Paper-based | 35 | Hpv | Closed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Shapiro GK, 2016 | 2014 | Canada | Cross-sectional | On-line | 1,427 | Hpv | Mixed | Not | Hesitancy/scepticism/doubt |
| Shapiro GK, 2017 | 2016-2017 | Canada | Cross-sectional | On-line | 4,606 | Hpv | Open field | Statistical methods not reported | Acceptance |
| Shawn DH, 1987 | 1986 | Canada | Cross-sectional | Paper-based | 133 | Hib | Closed | Statistical methods not reported | Hesitancy/scepticism/doubt |
| Sheikh A, 2013 | 2012-2013 | Pakistan | Cross-sectional | Paper-based | 1,044 | Polio/tetanus/measles | Closed | Not | Hesitancy/scepticism/doubt |
| Shuaib FM, 2010 | 2008 | Jamaica | Case-control | Paper-based | 285 | Child vaccines | Closed | Not | Hesitancy/scepticism/doubt |
| Skinner J, 1995 | 1992 | Australia | Cohort | 1,004 | Child vaccines | Mixed | Statistical methods not reported | Acceptance | |
| Smailbegovic MS, 2003 | 1999 | UK | Case-control | On-line | 129 | Child vaccines | Closed | Not | Hesitancy/scepticism/doubt |
| Smith MJ, 2009 | 2009 | USA | Cross-sectional | On-line | 121 | Child vaccines | Mixed | Not | Hesitancy/scepticism/doubt |
| Smith PJ, 2011 | 2009 | USA | Cross-sectional | Telephone | 11,206 | Child vaccines | Closed | Not | Hesitancy/scepticism/doubt |
| Smith PJ, 2010 | 2003 | USA | Cross-sectional | Telephone | 2,921 | Child vaccines | Closed | Not | Hesitancy/scepticism/doubt |
| Smith PJ, 2006 | 2001-2002 | USA | Cross-sectional | Telephone | 7,695 | Child vaccines | Closed | Not | Hesitancy/scepticism/doubt |
| Smith PJ, 2015 | 2010-2013 | USA | Cross-sectional | Telephone | 19,144 | Measles | Closed | Not | Hesitancy/scepticism/doubt |
| Smith PJ, 2016 | 2010-2014 | USA | Cross-sectional | Telephone | 8,490 | Hpv | Closed | Not | Hesitancy/scepticism/doubt |
| Sohail MM, 2015 | N.A. | Pakistan | Cross-sectional | Paper-based | 200 | Child vaccines | Mixed | Not | Acceptance |
| Songthap A, 2012 | 2012 | Thailandia | Cross-sectional | Paper-based | 664 | Hpv | Closed | Not | Hesitancy/scepticism/doubt |
| Soyer OU, 2011 | 2003 | USA | Cross-sectional | Telephone | 500 | Flu | Mixed | Not | Acceptance |
| Staras SA, 2014 | 2009 | Usa | Cross-sectional | Telephone | 2,422 | Hpv | Closed | Not | Acceptance |
| SteelFisher GK, 2015 | 2013-2014 | Multinational | Cross-sectional | Paper-based | 6,025 | Polio | Closed | Not | Acceptance |
| Stefanoff P, 2010 | 2008-2009 | Multinational | Cross-sectional | Telephone, paper-based, mail | 6,611 | Child vaccines | Mixed | Not | Acceptance |
| Stein Zamir C, 2017 | 2015 | Israel | Cross-sectional | Paper-based | 45 | Child vaccines | Closed | Not | Acceptance |
| Stephenson JD, 1987 | 1986 | Canada | Cross-sectional | Paper-based | 133 | Hib | Closed | Not | Hesitancy/scepticism/doubt |
| Stockwell MS, 2014 | 2007-2008 | USA | Cross-sectional | Paper-based | 705 | Child vaccines | Mixed | Not | Acceptance |
| Strelitz B, 2015 | 2013-2014 | USA | Cross-sectional | Paper-based | 152 | Flu | Likert scale | Not | Hesitancy/scepticism/doubt |
| Stretch R, 2008 | 2007-2008 | UK | Cross-sectional | Paper-based | 651 | Hpv | Likert scale | Statistical methods not reported | Acceptance |
| Suarez-Castaneda E, 2014 | 2011 | El Salvador | Cross-sectional | Paper-based | 2,550 | Child vaccines | Mixed | Not | Acceptance |
| Sundaram SS, 2010 | N.A. | UK | Cross-sectional | Paper-based | 50 | Hpv | Likert scale | Not | Acceptance |
| Tadesse H, 2009 | 2008 | Ethiopia | Case-control | Paper-based | 266 | Child vaccines | Mixed | Statistical methods not reported | Acceptance |
| Tagbo BN, 2014 | 2014 | Nigeria | Cross-sectional | Paper-based | 426 | Polio | Likert scale | With statistical methods | Hesitancy/scepticism/doubt |
| Taiwo L, 2017 | 2015 | Nigeria | Cross-sectional | Paper-based | 379 | Child vaccines | Mixed | Not | Hesitancy/scepticism/doubt |
| Takahashi K, 2014 | 1999-2003 | Japan | Cross-sectional | Paper-based | 120 | Measles | Mixed | Not | Refusal |
| Tam WW, 2015 | 2003 | HongKong | Cross-sectional | Paper-based | 5,617 | Varicella | Likert scale | Not | Acceptance |
| Tan TNQ, 2017 | 2011-2013 | USA | Cross-sectional | Paper-based | 516 | Hpv | Mixed | Not | Acceptance |
| Tang CW, 2011 | 2006-2008 | Taiwan | Cross-sectional | Paper-based | 539 | Child vaccines | Mixed | Statistical methods not reported | Acceptance |
| Taylor JA, 1996 | 1993 | USA | Case-control | Paper-based | 194 | Child vaccines | Likert scale | Statistical methods not reported | Acceptance |
| Taylor JA, 2002 | 1998-2000 | USA | Cross-sectional | Paper-based | 13,520 | Child vaccines | Mixed | Not | Acceptance |
| Thomas T, 2015 | N.A. | Georgia | Cross-sectional | Paper-based | 37 | Hpv | Mixed | Not | Hesitancy/scepticism/doubt |
| Thomas TL, 2012 | 2010-2011 | USA | Cross-sectional | Paper-based | 400 | Hpv | Mixed | Not | Hesitancy/scepticism/doubt |
| Thomas TL, 2013 | 2009 | USA | Cross-sectional | Paper-based | 200 | Hpv | Likert scale | Statistical methods not reported | N.A. |
| Thomas TL, 2017 | 2010-2011 | USA | Cross-sectional | Paper-based | 341 | Hpv | Likert scale | Not | Acceptance |
| Thompson EL, 2017 | 2012-2015 | USA | Cross-sectional | Telephone | 59,897 | Hpv | Closed | With statistical methods | Hesitancy/scepticism/doubt |
| Tisi G, 2013 | 2011 | Italy | Cross-sectional | Paper-based | 161 | Hpv | Mixed | Not | Acceptance |
| Taylor, JA, 2000 | 1997-1998 | USA | Cross-sectional | Paper-based | 598 | Varicella | Likert scale | Not | Hesitancy/scepticism/doubt |
| Schwartz B, 2000 | 2000-2001 | USA | Cross-sectional | Telephone | 12,060 | Hbv/dtp/measles/varicella | Mixed | Not | N.A. |
| Streng A, 2010 | 2006-2008 | Germany | Cross-sectional | Paper-based | 1,088 | Varicella | Mixed | Statistical methods not reported | Acceptance |
| Opel DJ, 2011 | 2010 | USA | Cross-sectional | 228 | Dtp/polio/mmr | Likert scale | Not | Hesitancy/scepticism/doubt | |
| World Health Organization, 1997 | 1994 | Italy | Cross-sectional | Face to face | 1,800 | Dtp/polio | Closed | With statistical methods | Hesitancy/scepticism/doubt |
N.A.: not available.