Literature DB >> 34520323

Knowledge of HPV, its vaccines, and attitudes toward HPV vaccines among obstetrician-gynecologists, pediatricians and immunization services providers in Western China.

Jianqiao Ma1, Xi Zhang2, Wei Wang3, Rong Zhang4, Mei Du5, Li Shan6, Yucong Li7, Xiaohui Wang8, Yijun Liu9, Wen Zhang10, Xiaoling Li11, Youlin Qiao12, Mengna Wei13, Hui Chen1, Jing Zhou1, Jing Li1,14.   

Abstract

BACKGROUND: In mainland China, HPV vaccines have been available to the public. However, only a few related studies among health care providers, as the key information providers, were reported although public concerns on HPV vaccines still exist. In this study, we aim to assess the knowledge of HPV, its vaccines, and attitudes toward HPV vaccines among the three most important groups of health care providers in Western China.
METHOD: This was a cross-sectional questionnaire-based study. Health care providers including obstetrician-gynecologists (OB-GYNs), pediatricians, and immunization service providers in Western China were investigated regarding their knowledge of HPV and its vaccines and their attitudes toward HPV vaccines.
RESULTS: Of 1079 health care providers completing the survey, 1015 (94.1%) knew HPV infection is the primary cause of cervical cancer. However, lower knowledge levels of other HPV-related diseases were also found (43.2%). About three-quarters (74.1%) of practitioners interviewed would be willing to recommend HPV vaccination, which was found to be lower among the OB-GYNs (69.6%) and the pediatricians (73.2%). "Lack of relevant knowledge," "concerns on safety and efficacy" and price were the three most important concerns surrounding HPV vaccination.
CONCLUSION: The interviewed practitioners did not have adequate knowledge of HPV and its vaccines in depth. Education interventions are highly recommended to the health care providers, especially for OB-GYNs and pediatricians, to increase the coverage of HPV vaccination among the population. For the currently high price of vaccines, a future co-sharing mechanism between the government, the providers, and the individuals might be a solution.

Entities:  

Keywords:  HPV vaccination; Western China; attitude; immunization services providers; knowledge; obstetrician-gynecologists; pediatricians

Mesh:

Substances:

Year:  2021        PMID: 34520323      PMCID: PMC8920158          DOI: 10.1080/21645515.2021.1962150

Source DB:  PubMed          Journal:  Hum Vaccin Immunother        ISSN: 2164-5515            Impact factor:   3.452


Introduction

Cervical cancer is the second most commonly diagnosed cancer among females in developing countries,[1] due to the lack of effective screening and preventative programs.[2] In Eastern Asia, the incidence of cervical cancer was 10.9/100,000 in 2018, higher than in Western Asia.[3] Persistent high-risk HPV infection has been shown to be involved in the increased risk of high-grade cervical intraepithelial neoplasia (CIN) and cancer.[4] Prophylactic HPV vaccines have been demonstrated to be effective and safe at preventing the development of high-grade cervical neoplasias since the vaccines were first approved in 2006.[5,6] In China, the bivalent vaccine for HPV 16 and 18 (Cervarix®, GlaxoSmithKline Biologicals, Rixensart, Belgium) and the quadrivalent vaccine for HPV 6, 11, 16, and 18 (Gardasil®, Merck and Co., Whitehouse Station, NJ) were approved in 2016 and 2017, respectively.[7,8] The nonavalent vaccine has also been commercially available in mainland China.[9] In December 2019, the China-made bivalent vaccine for HPV 16 and 18 (Cecolin®) has been approved by the China Food and Drug Administration.[10] However, public concerns surrounding HPV vaccines, especially their safety and efficacy, still exist in some areas.[11-13] In mainland China, a few studies have been conducted among junior middle school students,[14] their parents,[15] and women who attended cervical cancer screening[16] to explore their knowledge and attitudes toward HPV and its vaccines. Although health care providers are the key information providers for the population to ensure effective vaccination coverage in the future,[17-21] little is known about the knowledge level and attitudes toward HPV vaccines among obstetrician-gynecologists (OB-GYNs), pediatricians, and immunization services providers, who are considered to be the three most important groups among Chinese health care providers to promote HPV vaccination: pediatricians, as pioneers, play an important role in recommending HPV vaccines to the primary group to be vaccinated; OB-GYNs contribute to catch-up doses for adult women; immunization services providers, play a crucial role in the successful implementation of immunization in China.[22] Our study aims to explore the knowledge of HPV, its vaccines, and attitudes toward HPV vaccines among OB-GYNs, pediatricians, and immunization services providers in the less developed Western China. We hope to understand the current situation of the three groups regarding their ability to deliver accurate information on HPV and its vaccines and to make sure they help the target population and/or their guardians to make appropriate decisions. Our study also aims to provide a reference of a tailored evidence-based health education intervention targeting health care providers from different specialties in the future with the purpose to eventually increase the uptake of HPV vaccines in China.

Materials and methods

Study design and participants

This was a cross-sectional questionnaire-based study that ran from November 2018 to July 2019. Convenience sampling was used to invite 12 collaborative medical centers from Western China, including Chongqing University Cancer Hospital, Chengdu Women’s and Children’s Central Hospital, Meishan Maternal and Children’s Hospital, Neijiang Center of Disease Control and Prevention, Deyang Maternal and Children’s Hospital, Kunming Women and Children’s Hospital, Dali Maternal & Child Health Hospital, Yuxi Hospital of Traditional Chinese Medicine, Zunyi Medical University Hospital, Northwest Women’s and Children’s Hospital, Xinjiang Medical University and Gansu Provincial Cancer Hospital. The collaborative institutions invited local health care providers, including OB-GYNs, pediatricians, immunization services providers, internists, and those from other specialties to attend free health education regarding cervical cancer prevention by sending both paper and electronic invitations. Our surveys were conducted before the health education took place. In this article, the results of OB-GYNs, pediatricians and immunization services providers were selected for analysis.

Research instrument

The anonymous self-completed questionnaires were administered after a detailed explanation by the researchers. The questionnaire contained four parts: (i) the social demographic characteristics (including the gender, age, current employment, education, region, specialty, years in practice, etc.); (ii) knowledge of HPV and its related diseases, e.g. the primary cause of cervical cancer, the major two subtypes of hr-HPV, other HPV related diseases, etc.; (iii) knowledge of epidemiology in HPV & cervical cancer, e.g., the possibility of being infected by HPV, the age distribution pattern of HPV, etc.; (iv) knowledge of HPV vaccines, e.g. efficacy and safety, possible side effects, whether an HPV test is necessary before vaccination, whether HPV vaccination is still recommended after a positive test result or treatment, whether screening is still necessary after vaccination; (v) attitudes toward HPV vaccines, e.g. willingness to recommend HPV vaccination to the appropriate population.

Data collection and quality control

Two graduate and two undergraduate students were assigned to double-enter the data independently after training. Any inconsistency found between the two databases would be adjusted based on the original questionnaire-based questionnaires until the elimination of the inconsistency. Logic errors (e.g. a participant who responded as being willing to recommend HPV vaccines to the public chose the reasons they were unwilling to recommend HPV vaccination) were again double-checked and revised. After the consistency and logic checks, the database was ready for the final analysis.

Statistical analysis

SPSS statistical software version 20.0 was used to analyze the data. Frequency and percentages were used to describe the characteristics of participants, related knowledge, as well as attitudes toward HPV vaccines. Chi-squared test or Fisher’s exact test was used to analyze the differences among OB-GYNs, pediatricians, and immunization services providers. Logistic regression was used to analyze the influential factors of attitudes toward HPV vaccines. Statistical significance was assessed by two-tailed tests with an α level of 0.05.

Results

Participants profile

There were a total of 1797 health care providers attending the health education. 1459 (81.2%) participants out of 1797 entered our surveys before the educational interventions, with 1448 (99.2%) completed out of 1459. Among the completed 1448 questionnaires, there were 1079 (74.5%) from the three specialties, including 595 OB-GYNs, 71 pediatricians, and 413 immunization services providers from 7 different provinces/autonomous regions in Western China. The majority of the 1079 participants were females (85.4%) and the mean age was 37.7 years (s.d. = 9.5 years). 21.2% of participants were aged younger than 29 years of age, more than half of them aged between 30–49 years (30–39 yrs (28.0%) and 40–49 yrs (26.7%)). Most (78.8%) of participants came from urban areas, while one-fifth (19.3%) of them were from rural areas. 30.4% of participants were from community hospitals, approximately half (52.2%) of them working at general hospitals or women’s and children’s hospitals, and only 8.1% of them working at CDC. Among all participants, 38.8% had graduated from junior colleges, about half of them (52.5%) had bachelor’s degrees and very few had master’s or doctor’s degrees (6.2%). About one-third (36.9%) of participants were from Sichuan Province, followed by Yunnan (25.8%) and Gansu (12.6%). More than a quarter (26.4%) of participants had been working for more than 21 years (Table 1).
Table 1.

The distribution of social demographics among health care providers

Social demographicsTotal (N = 1079)
 OB-GYNs (n = 595)
Pediatricians (n = 71)
Immunization services providers (n = 413)
n% n%n%n%
Gender         
 male575.3 203.4811.3297.0
 female92285.4 52688.45881.733881.8
 missing data1009.3 498.257.04611.1
Age (years)         
 ≤2922921.2 9916.62231.010826.2
 30–3930228.0 16527.71521.112229.5
 40–4928826.7 18731.41825.48320.1
 ≥5013012.0 8814.857.0379.0
 missing data13012.0 569.41115.56315.3
Region         
 urban85078.8 51486.45780.327967.6
 rural20819.3 6310.61419.713131.7
 othera151.4 142.400.010.2
 missing data60.6 40.700.020.5
Current Employment         
 community hospital32830.4 6711.32839.423356.4
 general hospital or women’s and children’s hospital56352.2 46578.23650.76215.0
 CDC878.1 30.522.88219.9
 other989.1 599.957.0348.2
 missing data30.3 10.200.020.5
Education         
 junior college41938.8 14624.54360.623055.7
 bachelor56652.5 38965.42231.015537.5
 master or doctor676.2 549.145.692.2
 other262.4 61.022.8184.4
 missing data10.1 00.000.010.2
Provinceb         
 Sichuan39836.9 11619.51825.426463.9
 Yunnan27825.8 24441.02636.681.9
 Gansu13612.6 579.6912.77016.9
 Guizhou837.7 6911.600.0143.4
 Xinjiang746.9 447.4811.3225.3
 Shannxi585.4 498.222.871.7
 Chongqing524.8 162.7811.3286.8
Years in practice         
 ≤524222.4 11118.72231.010926.4
 6–1020318.8 9916.61216.99222.3
 11–1516915.7 10117.01115.55713.8
 16–2017816.5 10417.51014.16415.5
 ≥2128526.4 17829.91622.59122.0
 missing data20.2 20.300.000.0

a: “other” means the combination zones between urban and rural areas; b: in our study, Sichuan province includes Chengdu (137), Deyang (103), Meishan (34) and Neijiang (124); Yunnan province includes Kunming (155), Dali (83) and Yuxi (40); Guizhou province includes Zunyi (83); Gansu province includes Lanzhou (136); Shannxi province includes Xi’an (58); Xinjiang Autonomous Region includes Urumchi (74); Chongqing (52) is a municipality.

The distribution of social demographics among health care providers a: “other” means the combination zones between urban and rural areas; b: in our study, Sichuan province includes Chengdu (137), Deyang (103), Meishan (34) and Neijiang (124); Yunnan province includes Kunming (155), Dali (83) and Yuxi (40); Guizhou province includes Zunyi (83); Gansu province includes Lanzhou (136); Shannxi province includes Xi’an (58); Xinjiang Autonomous Region includes Urumchi (74); Chongqing (52) is a municipality.

Knowledge toward HPV and its vaccines

In our study, 94.1% of participants knew that HPV infection is the primary cause of cervical cancer and 93.3% knew the most important two subtypes of hr-HPV. However, less than half of them (43.2%) knew the other HPV-related diseases, which was found to be higher among OB-GYNs (54.8%). The majority (84.6%) of them knew that HPV vaccination is the most effective way to prevent HPV infection and most of them (65.3%) were aware that more than 80% of sexually active women could be infected with HPV in their lifetime. About eighty percent (78.0%) of participants knew about the age distribution pattern of hr-HPV among Chinese women. Similarly, about eighty percent (78.3%) of participants knew HPV16 and HPV18 cause about 70% of cervical cancer worldwide. When asked about HPV vaccines, most of them thought the vaccine was safe (90.2%) and effective (84.2%). Around three-quarters (75.1%) knew the correct answers about the side effects. Only half (50.5%) of the health care providers knew that pre-vaccination HPV tests are not necessary. However, most of them (82.4%) would recommend HPV vaccination to their patients with positive HPV tests or even after treatment. For screening, 92.6% of the health care providers were fully aware that cervical cancer screening is recommended even after any of the HPV vaccinations. However, it was much lower (87.9%) among the immunization service providers (Table 2).
Table 2.

Knowledge of HPV, its vaccines and attitudes toward HPV vaccines among health care providers

Total (N = 1079)
 OB-GYNs (n = 595)
Pediatricians (n = 71)
Immunization services providers (n = 413)
 χ2 test
N% n%n%n% P value
Knowledge of HPV-Related Diseases
1.What is the primary cause of cervical cancer? (HPV infection) b
101594.1 56494.86997.238292.5 .183a
2.What are the most important two subtypes of high risk HPV? (HPV 16/18) b
100793.3 57095.86185.937691.0 <.001a
3.What other diseases HPV can cause except for cervical cancer? (Anal cancer/Genital warts/carcinoma of the penis/Oropharyngeal cancer) b
46643.2 32654.81825.412229.5 <.001
4.What is the most effective prevention from HPV infection? (HPV vaccine) b
91384.6 47179.26185.938192.3 <.001
Knowledge of Epidemiology in HPV & Cervical Cancer   
5.What is the possibility that sexual active women would be infected by HPV in their lifetime, although 90% of the infection would be spontaneously regress within 12–24 months (Around 80%) b
70565.3 40968.74259.225461.5 .031
6.What is the age distribution pattern of high risk HPV among Chinese women? (Bimodal distribution) b
84278.0 47379.55476.131576.3 .438
7.What are the most important HPV subtypes that cause about 70% of cervical cancer worldwide? (HPV 16 and 18) b
84578.3 48080.75374.731275.5 .112
Knowledge of HPV Vaccines   
8. Is HPV vaccine safe? (Yes)
97390.2 53089.15881.738593.2 .004
9. Is HPV vaccine effective? (Yes)
90984.2 47980.55780.337390.3 <.001
10.What are the possible side effects after HPV vaccination? (Local redness, swelling, heat and pain; fever, headache, vertigo) b
81075.1 43973.85070.432177.7 .234
11.Is HPV test needed before HPV vaccination? (No) b
54550.5 25843.43143.725662.0 <.001
12.Is HPV vaccine still recommended even with a positive HPV test or after treatment? (Yes) b
88982.4 49082.45881.734182.6 .983
13.Is screening recommended after HPV vaccination? (Yes) b
99992.6 57095.86693.036387.9 <.001
Attitudes toward HPV vaccines   
14.Are you willing to recommend HPV vaccination to your patients?
79974.1 41469.65273.233380.6 <.001

a: Fisher’s exact test; b: referential answer. Boldface reflects statistical significance.

Knowledge of HPV, its vaccines and attitudes toward HPV vaccines among health care providers a: Fisher’s exact test; b: referential answer. Boldface reflects statistical significance.

Attitudes toward HPV vaccines

Of all, 74.1% of the health care providers would recommend HPV vaccination to their patients, and the immunization service providers (80.6%) were the most likely to do this (Table 2). When the remaining 25.9% were questioned about the reasons why they were not willing to recommend HPV vaccination, “Lack of relevant knowledge” (62.1%), “concerns on the efficacy and safety regarding HPV vaccines” (53.6%), and “do not want to be regarded as hard-selling because of its high price” (45.0%) were the top three obstacles (Table 3).
Table 3.

Main reasons for health care providers not to recommend HPV vaccination.a

 Total (N = 280)
 OB-GYNs (n = 181)
Pediatricians (n = 19)
Immunization services providers (n = 80)
χ2 test
N%n%n%n%P value
1Lack of relevant knowledge about HPV vaccines.
 17462.1 11060.81368.45163.8.759
2Concerns on the efficacy and safety.
 15053.6 10256.41263.23645.0.163
3Do not want to be regarded as hard-selling because of the high price.
 12645.0 8144.8842.13746.3.942
4It is not convenient to talk about because it is sexual related.
 4014.3 1910.5526.31620.0.030b
5Patients are not knowledgeable about HPV, so it is a waste of time to talk to them.
 3311.8 168.8421.11316.3.078b
6Screening is enough, so there is no need for HPV vaccination.
 238.2 137.215.3911.3.585b

a: “not to recommend HPV vaccination” including “not to recommend” and “not clear”; b: Fisher’s exact test. Boldface reflects statistical significance.

Main reasons for health care providers not to recommend HPV vaccination.a a: “not to recommend HPV vaccination” including “not to recommend” and “not clear”; b: Fisher’s exact test. Boldface reflects statistical significance.

Influential factors of attitudes toward HPV vaccines

For social demographics, logistic regression revealed that education and specialty are the major influential factors of attitudes toward HPV vaccines. Health care providers with a bachelor’s degree (OR = 2.97, P= .043), as well as a master’s or doctor’s degree (OR = 5.16, P= .012), were more likely to recommend HPV vaccination, compared with those with “other degree.” OB-GYNs, according to our study, showed less willingness to recommend HPV vaccination (OR = 0.44, P= .002), compared with immunization services providers. Guizhou Province was less likely to recommend HPV vaccination (OR = 0.30, P= .021), compared with Chongqing (Table 4).
Table 4.

Logistic Regression for social demographics of attitudes toward HPV vaccines

CharacteristicsOR95%CIP value
Gender    
  male0.660.321.34.245
  female1   
Age (years)    
 ≤290.780.262.35.664
 30–391.060.442.54.904
 40–491.110.631.94.727
 ≥501   
Region    
 urban0.200.031.60.129
 rural0.190.021.55.120
 othera1   
Current Employment    
 community hospital1.200.652.23.557
 general hospital or women’s and children’s Hospital1.771.003.13.050
 CDC2.340.796.90.124
 other1   
Education    
 junior college2.100.755.91.158
 bachelor2.971.048.52.043
 master or doctor5.161.4318.59.012
 other1   
Province    
 Sichuan0.710.281.76.457
 Yunnan0.440.181.11.081
 Gansu0.400.151.02.054
 Guizhou0.300.110.83.021
 Xinjiang2.410.5610.34.235
 Shannxi0.390.141.11.076
 Chongqing1   
Years in practice    
 ≤51.500.534.25.448
 6–101.290.543.10.571
 11–151.210.562.63.631
 16–201.380.782.46.272
 ≥211   
Specialty    
 OB-GYNs0.440.260.74.002
 pediatricians0.650.311.36.254
 immunization services providers1   

a: “other” means the combination zones between urban and rural areas. Boldface reflects statistical significance.

Logistic Regression for social demographics of attitudes toward HPV vaccines a: “other” means the combination zones between urban and rural areas. Boldface reflects statistical significance.

Discussion

This is the first questionnaire-based evaluation on related knowledge, attitudes, and the reasons for not willing to recommend HPV vaccination among OB-GYNs, pediatricians, and immunization services providers in Western China. Therefore, our study aims to understand the current situation of the three groups regarding their ability to deliver accurate information on HPV and its vaccines, and provide a reference of a tailored evidence-based health educational intervention aimed at health care providers from different specialties. In our study, the knowledge level about other HPV-related diseases excluding cervical cancer was quite low (43.2%), similar to some other studies that found significant gaps in knowledge regarding HPV protection against diseases other than cervical cancer.[23,24] The low knowledge level regarding other HPV-related diseases was quite obvious among pediatricians (25.4%) and immunization services providers (29.5%), which may be because these groups do not have as much access to HPV-related training as OB-GYNs. However, even among OB-GYNs, the knowledge level was not high, as only about half (54.8%) were aware of the added protection that the vaccine provides against other diseases, which is similar to another study.[23] Increasing coverage of HPV vaccination in females at the routine age of 11 or 12 and catch-up vaccination through age 26 will contribute to a further reduction in cervical precancers,[25] which highlights the importance of OB-GYNs and pediatricians. However, in our study, only nearly eighty percent of OB-GYNs (79.2%) and pediatricians (85.9%) knew that HPV vaccination is the most effective way to prevent HPV infection. Additionally, only around seventy percent of OB-GYNs (69.6%) and pediatricians (73.2%) were willing to recommend HPV vaccination. According to the influential factors, although there was no significant association between pediatricians and attitudes toward HPV vaccines, it may be caused by insufficient samples of pediatricians. Therefore, it is suggested that pediatricians and OB-GYNs, whose practice mainly deals with children including teenagers, as well as women, held particularly negative attitudes toward HPV vaccines. This finding poses an alarming signal to the Chinese government if the World Health Organization (WHO) recommends that the target population is to be significantly covered by vaccination. Fortunately, in our study, we also explored the reasons why they were not willing to recommend the vaccination, on which basis we proposed the possible solutions. The primary reason not to recommend HPV vaccination was the lack of relevant knowledge, for 60.8% of OB-GYNs and 68.4% of pediatricians among the unwilling population admitted to this. Therefore, we recommend that more tailored health education aimed at health care providers, especially for OB-GYNs and pediatricians, should be one of the interventions to eliminate their false beliefs and to, therefore, increase the vaccination coverage. The efficacy and safety of the HPV vaccines have been already confirmed.[5,6,26] Moreover, even when inadvertently administered in pregnancy or during the preconception period, HPV vaccines were not associated with adverse pregnancy or birth outcomes.[27] However, such information has not been delivered efficiently to the public or even to some health care providers. On the one hand, for the public, a previous study has reported that when parents were asked about their most pressing concerns about HPV vaccines from their children’s health care providers, their answers were safety and side effects.[28] For health care providers from our study, on the other hand, insufficient knowledge level (75.1%) regarding side effects and “concerns on the efficacy and safety” (which was the second important reason not to recommend, as half (53.6%) of the unwilling population indicated), indirectly led to the reduced acceptance of HPV vaccination by the public. Therefore, our study suggests that health care providers in Western China need to be better informed regarding HPV vaccine-related knowledge in the future process of health education, especially about the efficacy and safety. The age distribution of HPV prevalence among Chinese women is bimodal, with one peak around 20 years and the other around 45 years,[29] which poses great challenges for HPV prevention in the Chinese population as well as in other populations that share a similar distribution pattern. Currently, no HPV vaccine on the market covers all types of hr-HPV that cause cervical cancer, which means that screening after vaccination is still necessary. In our study population, 22% of practitioners reported to have never heard about the “bimodal distribution,” and 7.4% thought that “screening is no longer needed after HPV vaccination” which was even worse among the immunization services providers (12.1%). Therefore, primary prevention via vaccination plus secondary prevention via screening should both be taken into consideration in the future for cervical cancer-related training. Apart from the lack of knowledge and concerns on efficacy and safety, price is the third most important reason that led to the unwillingness to recommend vaccination among the practitioners. Therefore, a two-dose schedule should be considered,[30] or a novel co-sharing price mechanism as well as an expanded EPI (Expanded Program on Immunization), should also be thought about to reduce the price. Additionally, more cost-effective vaccines, such as domestic or bivalent vaccines, are recommended to stakeholders if decent vaccination coverage is expected. There were some limitations to our study. First, to ensure feasibility, this study was conducted in only one or two local hospitals, which may result in a lack of representation by our study. Second, there was a small sample size of pediatricians involved in our study, which may also reduce our persuasiveness. One of the major strengths of this study is that this is the first study to investigate the knowledge of HPV, its vaccines, and attitudes toward HPV vaccines among OB-GYNs, pediatricians, and immunization services providers in Western China. This study helps to provide important information to policymakers on how important health education is if future decent coverage of HPV vaccination is expected, and it also provides the reference of a tailored evidence-based health educational intervention aimed at health care providers from different specialties.

Conclusion

Our results indicated that the health care providers in Western China did not have adequate knowledge of HPV and its vaccines in depth. Our results also showed that around 30% of OB-GYNs and pediatricians were not willing to recommend HPV vaccination due to lack of knowledge, as well as doubts on safety and efficacy, posing a great challenge for cervical cancer control in less developed areas. Therefore, more tailored and specific health educations targeting health care providers to eliminate their prejudices and false beliefs are of great importance.[31] Price is another issue that should be taken into consideration by stakeholders if decent vaccination coverage is to be expected in the future, especially in resource-limited areas of China.
  30 in total

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Authors:  Jie Chang; Zhiyuan Hou; Hai Fang; Qingyue Meng
Journal:  Vaccine       Date:  2019-06-04       Impact factor: 3.641

Review 2.  Beliefs around childhood vaccines in the United States: A systematic review.

Authors:  Courtney Gidengil; Christine Chen; Andrew M Parker; Sarah Nowak; Luke Matthews
Journal:  Vaccine       Date:  2019-09-24       Impact factor: 3.641

3.  Factors associated with Human Papilloma Virus (HPV) vaccine recommendation by physicians in Lebanon, a cross-sectional study.

Authors:  Joseph Abi Jaoude; Diana Khair; Hiba Dagher; Halim Saad; Patrick Cherfan; Mohamad Ali Kaafarani; Zeina Jamaluddine; Hala Ghattas
Journal:  Vaccine       Date:  2018-10-24       Impact factor: 3.641

4.  Human papillomavirus vaccine against cervical cancer: Opportunity and challenge.

Authors:  Renjie Wang; Wei Pan; Lei Jin; Weiming Huang; Yuehan Li; Di Wu; Chun Gao; Ding Ma; Shujie Liao
Journal:  Cancer Lett       Date:  2019-12-05       Impact factor: 8.679

5.  Long-term absolute risk of cervical intraepithelial neoplasia grade 3 or worse following human papillomavirus infection: role of persistence.

Authors:  Susanne K Kjær; Kirsten Frederiksen; Christian Munk; Thomas Iftner
Journal:  J Natl Cancer Inst       Date:  2010-09-14       Impact factor: 13.506

6.  Maternal and Infant Outcomes After Human Papillomavirus Vaccination in the Periconceptional Period or During Pregnancy.

Authors:  Heather S Lipkind; Gabriela Vazquez-Benitez; James D Nordin; Paul A Romitti; Allison L Naleway; Nicola P Klein; Rulin C Hechter; Michael L Jackson; Simon J Hambidge; Grace M Lee; Lakshmi Sukumaran; Elyse O Kharbanda
Journal:  Obstet Gynecol       Date:  2017-09       Impact factor: 7.661

7.  Prevalence of human papillomavirus and cervical intraepithelial neoplasia in China: a pooled analysis of 17 population-based studies.

Authors:  Fang-Hui Zhao; Adam K Lewkowitz; Shang-Ying Hu; Feng Chen; Long-Yu Li; Qing-Ming Zhang; Rui-Fang Wu; Chang-Qing Li; Li-Hui Wei; Ai-Di Xu; Wen-Hua Zhang; Qin-Jing Pan; Xun Zhang; Jerome L Belinson; John W Sellors; Jennifer S Smith; You-Lin Qiao; Silvia Franceschi
Journal:  Int J Cancer       Date:  2012-04-24       Impact factor: 7.396

8.  Awareness and attitude relating to the human papilloma virus and its vaccines among pediatrics, obstetrics and gynecology specialists in Turkey.

Authors:  Orkun Tolunay; Umit Celik; Seyfettin Senih Karaman; Tamer Celik; Salim Resitoglu; Cigdem Donmezer; Fahri Aydin; Huseyin Baspinar; Mustafa Kurthan Mert; Hasan Samsa; Sefa Arli
Journal:  Asian Pac J Cancer Prev       Date:  2014

9.  A pooled analysis of continued prophylactic efficacy of quadrivalent human papillomavirus (Types 6/11/16/18) vaccine against high-grade cervical and external genital lesions.

Authors:  Susanne K Kjaer; Kristján Sigurdsson; Ole-Erik Iversen; Mauricio Hernandez-Avila; Cosette M Wheeler; Gonzalo Perez; Darron R Brown; Laura A Koutsky; Eng Hseon Tay; Patricia García; Kevin A Ault; Suzanne M Garland; Sepp Leodolter; Sven-Eric Olsson; Grace W K Tang; Daron G Ferris; Jorma Paavonen; Matti Lehtinen; Marc Steben; F Xavier Bosch; Joakim Dillner; Elmar A Joura; Slawomir Majewski; Nubia Muñoz; Evan R Myers; Luisa L Villa; Frank J Taddeo; Christine Roberts; Amha Tadesse; Janine Bryan; Roger Maansson; Shuang Lu; Scott Vuocolo; Teresa M Hesley; Alfred Saah; Eliav Barr; Richard M Haupt
Journal:  Cancer Prev Res (Phila)       Date:  2009-09-29

10.  Low rate of human papillomavirus vaccination among schoolgirls in Lebanon: barriers to vaccination with a focus on mothers' knowledge about available vaccines.

Authors:  Maria J Abou El-Ola; Mariam A Rajab; Dania I Abdallah; Ismail A Fawaz; Lyn S Awad; Hani M Tamim; Ahmad O Ibrahim; Anas M Mugharbil; Rima A Moghnieh
Journal:  Ther Clin Risk Manag       Date:  2018-03-27       Impact factor: 2.423

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