ABSTRACT
Objective: The objective of this study was to analyze the 100 most cited studies on vaccine.
Methods: A comprehensive search of studies on vaccine was performed in the Web of Science Core Collection without year or language restrictions. The 100 top-cited studies were retrieved after screening abstracts or full-texts. The outcomes of bibliometric analysis included citation time, citation density, journal name, impact factor, publication year, article type, category, open access, and country of origin.
Results: The citation times for the 100 top-cited studies ranged from 593 to 2406, with a median citation times of 834. The 100 top-cited studies were published in 32 journals, and the journal with the most studies was New England Journal of Medicine (n = 20). They were published between 1969 and 2012, and 4 authors published at least 2 studies as the first author. The USA contributed the most studies (n = 70), followed by Switzerland (n = 4), England (n = 4) and Finland (n = 4). Eighty-one studies were published as Article, while 19 were Review. Eleven studies were about vaccine for therapeutic and 68 studies were about vaccine for prophylactic.
Conclusions: This is the first bibliometric analysis to provide a detailed list of the 100 most-cited studies on vaccine and helps to recognize the quality of the works, discoveries, and trends in the field.
Introduction
The vaccine is a biological preparation that provides active acquired immunity to a particular disease.Citation1−Citation3 The main types of vaccines include live-attenuated vaccine, inactivated vaccine, subunit, recombinant, polysaccharide, and conjugate vaccine and toxoid vaccine.Citation4 Vaccines help protect millions of healthy people,Citation4-Citation6 they are considered as the most economical and effective preventive measure against the most deadly infectious diseases.Citation2 WHO reported that 116 million infants worldwide received three doses of diphtheria-tetanus-pertussis vaccine, and about 85% of the world‘s children received one dose of measles vaccine by their first birthday through routine health services in 2015.Citation7
Studies for vaccine development have been conducted year by year,Citation2,Citation8-Citation10 although there has been marked progress in vaccine development, challenges still exist,Citation8,Citation11 including economic, vaccination for new emerging infectious diseases, and so on. The achievement on vaccine was reflected by scientific studies,Citation12 particularly in the most cited studies.Citation13,Citation14 Citation analysis is a type of bibliometric analysis in which evaluation and ranking of an article are done on the basis citation count.Citation15 Identification the milestones in a specific field can be done by analyzing the most cited study, especially by analyzing the 100 top-cited studies.Citation13,Citation14,Citation16,Citation17 Assessment of the 100 top-cited studies had been conducted for various diseases including tuberculosis,Citation18 diabetes,Citation14 emergency medicine,Citation19 etc. However, there is no such study on the vaccine. Thus, we performed the current study to identify the 100 top-cited studies on vaccine.
Results
Citation analysis
The 100 top-cited studies are listed in . They have been cumulatively cited 94,328 times. The median number of citations was 834, with a range of 593 to 2406. Only 3 studies were cited more than 2000 times, and a great number of studies (n = 32) were cited between 1000 and 2000 times. The first top-cited study was “Vaccination with irradiated tumor-cells engineered to secrete murine granulocyte-macrophage-colony-stimulating factor stimulates potent, specific, and long-lasting antitumor immunity” published by Dranoff et al. in Proceedings of The National Academy of Sciences of The United States of America in 1993.Citation20 The second top-cited study was by Schenk et al. and received 2384 citations. The article explained the immunization with amyloid-beta attenuates Alzheimer disease-like pathology in the PDAPP mouse and was published in 1999 in Nature.Citation21 The third top-cited paper was published by Nestle et al. and it studied the vaccination of melanoma patients by using peptide- or tumor lysate-pulsed dendritic cells. It was published in Nature Medicine.Citation22
Table 1. The 100 top-cited studies on vaccine
Journal
The 100 top-cited studies were published in 32 journals (). The journal with the highest publication number was New England Journal of Medicine(NEJM) (n = 20), followed by The Lancet (n = 11). The Science, Nature Medicine, Nature, Nature Reviews Immunology each have at least five highly cited studies; the remaining 27 journals contributed fewer than five studies each.
Table 2. Journals of the 100 top-cited studies on vaccine
The IFs(impact factors) for the journals with the 100 top-cited studies ranged from 2.305 to 79.26 (median 13.251). We found 79 of the top 100 studies were published in journals with IFs more than 10. For the top 4 medical journals, expect for BMJ, the NEJM, JAMA and Lancet each had at least one published top-cited studies. For the “CNS” journals, Nature and Science had at least one published top-cited studies, however, no top-cited study was published in Cell. There were 6 journals(Journal of Virology, American Journal of Epidemiology, European Journal of Immunology, Vaccine, Journal of Bacteriology, Pediatric Infectious Disease Journal) had lower IFs than 5 and contributed 1 or 2 studies each. We found there were no statistically significant correlations between the number of top-cited studies and journals’ IFs (P > .05).
Language and year
All 100 top-cited studies were published in the English language. They were published from 1969 to 2012 (); most of the studies were published in the 1990s and 2000s. We found that the highest number of studies was published in 2005.
Table 3. Years of the 100 top-cited studies on vaccine
Country
As shown in , a total of 16 countries produced 100 top-cited studies. The USA was the most productive country with 70 studies, followed by Switzerland, England, and Finland with 4 studies. Moreover, the United States had the highest total citation times (citation time: 67,581), Germany had the highest mean citation times per study (citation time: 1301).
Table 4. Countries of the 100 top-cited studies on vaccine
First author and contact author
lists the authors published more than one study as first authors and contact authors. For the first author, only 4 authors published more than one study as the first author, and they all published only two studies each. For contact authors, Rosenberg SA, Harper DM, Koutsky LA, Robinson HL, Seder RA, Stover CK were the most productive contact authors who published at least two studies.
Table 5. Authors with at least two studies as first author or contact author in the 100 top-cited studies on vaccine*
Publication type, open access, and Web of Science categories
For the type of the 100 top-cited studies, as shown in , 81 studies in the form of “Article” and 19 studies in the form of “Review” were cited 78,651 and 15,677 times, respectively. The studies in the form of “Article” had higher average citation times per study with 971 times than “Review” with 825 times. A total of 14 Web of Science research categories were identified. Medicine, General & Internal was the most popular category, with 33 studies, followed by Multidisciplinary Sciences with 21 studies and Immunology with 18 studies. The studies in the Medicine, General & Internal category were with the highest total citation times, however, Biochemistry & Molecular Biology had the highest mean citation times per study. As for the research category, 11 studies were about therapeutic vaccines, 68 studies were about prophylactic vaccines, and 21 studies cannot be divided into the therapeutic or prophylactic vaccine.
Table 6. Type of study and categories in the 100 top-cited studies on vaccine
Discussion
The study is the first bibliometric study summarizing several features of the most influential studies on vaccine. Understanding the characteristics of highly cited studies on vaccine may be worthwhile for several reasons. First, the findings of the present study could aid young researchers to keep themselves abreast of classic knowledge.Citation17 Second, trends identified by the current analysis may be of interest to clinicians in their clinical practice.Citation17 The studies cover important advancements on vaccine. Finally, the findings of the present analysis may help journal editors, reviewers, and funders in critically evaluating manuscripts and funding applications.Citation17
In our study, 100 top-cited studies were cited from 593 to 2406 times. The journal with the most studies was NEJM (n = 20). The studies were published between 1969 and 2012, and 4 authors published at least two studies as the first author. The USA produced the most studies (n = 70), followed by Switzerland (n = 4), England (n = 4) and Finland (n = 4). Eighty-one studies were in the form of “Article” and 19 studies in the form of “Review”. Medicine, General & Internal was the most popular category.
The present bibliometric analysis found that the100 top-cited studies were published in 32 journals. Nearly, four in the fifth of the studies were published in high impact factor journals. It should be noted that almost one-third of the 100 top-cited studies were published in 3 of top 4 medical journals, including JAMA, Lancet, and NEJM, while no study was published in BMJ. This phenomenon indicated that most researchers focused on not only the impact factor but also the influence in their research field when choosing journals to publish their studies.Citation17,Citation23 Of course, several other factors might influence the selection process of target journal,Citation13,Citation17,Citation24 including difficulty to be accepted, time from submission to acceptance, charges and so on. This is entirely different from some other fields, only a few numbers of studies were published in the four famous journals.Citation16,Citation17,Citation24 Why most of the top-cited vaccine studies are published in highly IF journals, the reasons might be that vaccine researches covers all aspects of medicine,Citation2,Citation9 which were quickly accepted by general medical journals. Besides, the most important vaccine researches should be published in the most famous medical journals, so that it can help the most populations.
In our study, original studies had higher mean citation times per study when compared with reviews. This finding indicated that vaccine researchers paid more attention to the new findings in this topic.Citation17 Besides, our bibliometric analysis proved that Medicine, General & Internal was the most popular category. The vaccine in clinical practice was indeed the most important,Citation2,Citation24,Citation25 which should raise more researchers’ concern. All the included studies were published in English. One of the main reasons for this is that English is the most common language of influential articles in the field of vaccine research.Citation26
The USA ranked first with 70 studies, which was more than the other countries. This finding was in accordance with other previous studies.Citation19,Citation27 The USA had the highest total citation times. Besides, most productive authors were from the USA. Overall, all this information supported that the USA made the most significant contribution to the developments of research on the vaccine. Our study found that some developing country such as China, Brazil and Chile were selected in rankings, which was entirely different from some other fields, such as infection in orthopedics.Citation19,Citation27 It should be noted that the two studies from China were not from China mainland, where has the most populations worldwide. Besides, no study was from India, which has the second largest population worldwide. Therefore, developing countries should try their best to improve the quality of vaccine articles in future.Citation26,Citation27
There are several limitations in this study. First, we selected the Web of Science Core Collection based on previous researches. Web of Science Core Collection does not include all vaccine articles; there is a probability of true top-cited articles that may be available in other databases such as Scopus and Google Scholar; therefore, the results of our study might not be comprehensive.Citation18,Citation28 Second, this was a cross-sectional study design with a single time point. The rankings identified may change if the study is replicated in the future.Citation26 Third, despite the methods described above, we could not guarantee that all retrieved articles accurately focused on this topic, which was an inherent weakness of all bibliometric analyses.Citation23 Despite limitations, we believed this study could contribute to obtaining vital developments of vaccines and providing new insights into innovation in this field.
In conclusion, the present analysis is the first reported attempt to recognize 100 top-cited studies in the field of vaccine. The observations of the present study reflect the exciting potential and the increasing role of vaccine in basic research and clinical practice. It also provides a reference of what may be considered as the most influential papers in vaccine and serves as an indication of what comprises a ‘highly citable’ manuscript for both researchers, clinicians, and healthcare providers. It also helps funding agencies to assess the whole significant research areas in the field to direct future research trends.
Materials and methods
The study was a retrospective bibliometric analysis, and there was no need for institutional review board approval.
Search method and strategy
We performed a search on January 10, 2019 using the Web of Science Core Collection database hosted by Clarivate Analytics as the previous studies.Citation18 The Web of Knowledge Core Collection is a multidisciplinary database with searchable author abstracts covering the journal literature of the sciences.Citation27 It fully indexes the major journals more than 170 subject categories, providing access to current information and retrospective data from 1945 forward.Citation24 Based on a pilot search, the author found that some top-cited studies mentioning the word immunization in the abstract are not related to the vaccine, and these studies should be excluded. Thus, the search was performed by two steps: first, we search the following words: vaccine or vaccination; second, we search the following words: immunization. The identified publications were sorted in descending order of citation times. Only studies concerning the vaccines were included.
Data extraction
The 100 top-cited vaccine studies were identified by citation times. They were sorted in descending order of citation times. The following data were extracted, including the author, affiliation, country, journal, language, Web of Science category, publication year, number of citations, number of pages, and status of open access, the publication type. The country of affiliation was identified by using the country of the contact author. If the contact author had more than one affiliations from different countries, the country of the first affiliation was extracted. If one study was categorized into more than one categories, the first category was extracted.Citation18 The majority of vaccines are prophylactic for infectious diseases, a smaller number are therapeutic, typically for cancer and autoimmune disease, so the studies were divided into therapeutic study and prophylactic study, if the study could not be divided into the two types of studies, it was divided into the other group.
Data analysis
Data analysis was performed using SPSS 17.0 software. The following outcomes were analyzed: citation times, year, country, author, journal, language, publication type, open access and Web of Science categories and research categories.
Disclosure of potential conflicts of interest
No potential conflicts of interest were disclosed.
Ethics committee approval
This is a bibliometric analysis, so ethics approval is not applicable.
Related Research Data
References
- Poland GA, Kennedy RB, Ovsyannikova IG, Palacios R, Ho PL, Kalil J. Development of vaccines against Zika virus. Lancet Infect Dis. 2018;18:e211–e9. doi:10.1016/S1473-3099(18)30063-X.
- Hotez PJ, Bottazzi ME, Strych U. New vaccines for the world‘s poorest people. Annu Rev Med. 2016;67:405–17. doi:10.1146/annurev-med-051214-024241.
- Haber P, Amin M, Ng C, Weintraub E, McNeil MM. Reports of lower respiratory tract infection following dose 1 of RotaTeq and Rotarix vaccines to the vaccine adverse event reporting system (VAERS), 2008-2016. Hum Vaccin Immunother. 2018;1–5. doi:10.1080/21645515.2018.1491509.
- Demicheli V, Jefferson T, Di Pietrantonj C, Ferroni E, Thorning S, Thomas RE, Rivetti A. Vaccines for preventing influenza in the elderly. Cochrane Database Syst Rev. 2018;2:CD004876.
- Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V. Vaccines for preventing influenza in healthy children. Cochrane Database Syst Rev. 2018;2:CD004879.
- Hu Y, Chen Y, Liang H, Wang Y. Routine vaccination coverage of children aged 1-7 years in Zhejiang province, China. Hum Vaccin Immunother. 2018;14:2876–83. doi:10.1080/21645515.2018.1486156.
- Casey RM, Dumolard L, Danovaro-Holliday MC, Gacic-Dobo M, Diallo MS, Hampton LM, Wallace AS. Global routine vaccination coverage, 2015. MMWR Morb Mortal Wkly Rep. 2016;65:1270–73. doi:10.15585/mmwr.mm6545a5.
- Zanotto PMA, Leite LCC. The challenges imposed by dengue, zika, and chikungunya to Brazil. Front Immunol. 2018;9:1964. doi:10.3389/fimmu.2018.01964.
- Rauch S, Jasny E, Schmidt KE, Petsch B. New vaccine technologies to combat outbreak situations. Front Immunol. 2018;9:1963. doi:10.3389/fimmu.2018.01963.
- Song JY, Lim JH, Lim S, Yong Z, Seo HS. Progress toward a group B streptococcal vaccine. Hum Vaccin Immunother. 2018;1–13. doi:10.1080/21645515.2018.1493326.
- Mao QY, Wang Y, Bian L, Xu M, Liang Z. EV71 vaccine, a new tool to control outbreaks of hand, foot and mouth disease (HFMD). Expert Rev Vaccines. 2016;15:599–606. doi:10.1586/14760584.2016.1138862.
- Daley EM, Vamos CA, Zimet GD, Rosberger Z, Thompson EL, Merrell L. The feminization of HPV: reversing gender biases in US human papillomavirus vaccine policy. Am J Public Health. 2016;106:983–84. doi:10.2105/AJPH.2016.303084.
- Kolkailah AA, Fugar S, Vondee N, Hirji SA, Okoh AK, Ayoub A, Al-Ogaili A, Rios LHP, Kumar SK, Camacho MT, et al. Bibliometric analysis of the top 100 most cited articles in the first 50 years of heart transplantation. Am J Cardiol. 2019;123:175–86. doi:10.1016/j.amjcard.2018.09.010.
- Zhao X, Guo L, Lin Y, Wang H, Gu C, Zhao L, Tong X. The top 100 most cited scientific reports focused on diabetes research. Acta Diabetol. 2016;53:13–26. doi:10.1007/s00592-015-0813-1.
- Shen J, Li Y, Clarke M, Du L, Wang L, Zhong D. Visualization of evidence-based medicine domain knowledge: production and citation of Cochrane systematic reviews. J Evid Based Med. 2013;6:34–42. doi:10.1111/jebm.12022.
- Berlinberg A, Bilal J, Riaz IB, Kurtzman DJB. The 100 top-cited publications in psoriatic arthritis: a bibliometric analysis. Int J Dermatol. 2018. doi:10.1111/ijd.14261.
- Gondivkar SM, Sarode SC, Gadbail AR, Gondivkar RS, Choudhary N, Patil S. Citation classics in cone beam computed tomography: the 100 top-cited articles. Int J Dent. 2018;2018:9423281. doi:10.1155/2018/9423281.
- Zhang Y, Huang J, Du L. The top-cited systematic reviews/meta-analyses in tuberculosis research: A PRISMA-compliant systematic literature review and bibliometric analysis. Medicine (Baltimore). 2017;96:e4822. doi:10.1097/MD.0000000000004822.
- Shuaib W, Acevedo JN, Khan MS, Santiago LJ, Gaeta TJ. The top 100 cited articles published in emergency medicine journals. Am J Emerg Med. 2015;33:1066–71. doi:10.1016/j.ajem.2015.04.047.
- Dranoff G, Jaffee E, Lazenby A, Golumbek P, Levitsky H, Brose K, Jackson V, Hamada H, Pardoll D, Mulligan RC. Vaccination with irradiated tumor cells engineered to secrete murine granulocyte-macrophage colony-stimulating factor stimulates potent, specific, and long-lasting anti-tumor immunity. Proc Natl Acad Sci U S A. 1993;90:3539–43. doi:10.1073/pnas.90.8.3539.
- Schenk D, Barbour R, Dunn W, Gordon G, Grajeda H, Guido T, Hu K, Huang J, Johnson-Wood K, Khan K, et al. Immunization with amyloid-beta attenuates Alzheimer-disease-like pathology in the PDAPP mouse. Nature. 1999;400:173–77. doi:10.1038/22124.
- Nestle FO, Alijagic S, Gilliet M, Sun Y, Grabbe S, Dummer R, Burg G, Schadendorf D. Vaccination of melanoma patients with peptide- or tumor lysate-pulsed dendritic cells. Nat Med. 1998;4:328–32.
- Bullock N, Ellul T, Bennett A, Steggall M, Brown G. The 100 most influential manuscripts in andrology: a bibliometric analysis. Basic Clin Androl. 2018;28:15. doi:10.1186/s12610-018-0076-0.
- Yoon DY, Yun EJ, Ku YJ, Baek S, Lim KJ, Seo YL, Yie M. Citation classics in radiology journals: the 100 top-cited articles, 1945-2012. AJR Am J Roentgenol. 2013;201:471–81. doi:10.2214/AJR.12.10489.
- Zhu B, Dockrell HM, Ottenhoff THM, Evans TG, Zhang Y. Tuberculosis vaccines: opportunities and challenges. Respirology. 2018;23:359–68. doi:10.1111/resp.13245.
- Wu Y, Zhao Y, Lin L, Lu Z, Guo Z, Li X, Chen R, Ma H. Fifty top-cited spine articles from mainland China: A citation analysis. J Int Med Res. 2018;46:773–84. doi:10.1177/0300060517713804.
- Jiang Y, Hu R, Zhu G. Top 100 cited articles on infection in orthopaedics: A bibliometric analysis. Medicine (Baltimore). 2019;98:e14067. doi:10.1097/MD.0000000000014067.
- Chen W, Yu J, Tao H, Cai Y, Li Y, Sun X. Motherwort injection for preventing postpartum hemorrhage in pregnant women with cesarean section: A systematic review and meta-analysis. J Evid Based Med. 2018;11:252–60. doi:10.1111/jebm.2018.11.issue-4.