yan liu

Dr. yan liu


Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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23 June 2020 in Human Vaccines & Immunotherapeutics
Verified
Journal Article
Closed access
YXYuyang Xu
Yuyang Xu
YLyan liu
yan liu
XZXiaoping Zhang
Xiaoping Zhang
XZXuechao Zhang
Xuechao Zhang
JDJian Du
Jian Du
JCJunfang Chen
Junfang Chen
The varicella vaccine (VarV) is not included in the national childhood immunization schedules in China, although 2-dose VarV (VarV2) were recommended for children at 1 and 4 years of age in Hangzho...

12 June 2020 in Human Vaccines & Immunotherapeutics
Verified
Journal Article
Closed access
YLyan liu
yan liu
YXYuyang Xu
Yuyang Xu
JWJun Wang
Jun Wang
XCXinren Che
Xinren Che
WGWenwen Gu
Wenwen Gu
ZAzhijie an
zhijie an
23-valent pneumococcal polysaccharide vaccine (PPSV23) has been used to prevent pneumococcal disease, and PPSV23 became available in 2003 in Hangzhou, China as a private-sector, vaccinee-chosen vac...

6 January 2023 in Frontiers in Public Health
Verified
Journal Article
Open access
XCXinren Che
Xinren Che
YLyan liu
yan liu
WGWenwen Gu
Wenwen Gu
FWFangying Wang
Fangying Wang
JWJun Wang
Jun Wang
JWJing Wang
Jing Wang
Background: Although influenza vaccination is recommended for people aged 70 and above in Hangzhou, and the vaccine is provided free of charge, the elderly influenza vaccination rate is still low. The purpose of this study was to understand the barriers and motivations of older people in deciding to receive free influenza vaccine through questionnaires.Methods: The method of stratified random sampling was adopted to take samples. A questionnaire survey was conducted among the elderly aged 70 years and above by face-to-face interview or telephone interview.Results: A total of 11,663 elderly people aged 70–100 years were successfully and effectively interviewed. 85.98% of the respondent were willing to get the influenza shot, 8.91% were unwilling to get the influenza shot, and 5.11% were on vaccine hesitancy. The people of age of 70–79 years old (hesitancy: OR70~79 = 0.668, 95%CI: 0.571 0.782, Unwilling: OR70 − 79 = 0.755, 95%CI: 0.622 0.916), primary school degree or below (hesitancy: ORSecondary school degree or above = 1.467, 95%CI: 1.249 1.724, Unwilling: ORSecondary school degree or above = 1.255, 95%CI: 1.028 1.535), remote areas (hesitancy: ORnear central urban area = 2.111, 95%CI: 1.604 2.778, ORcentral urban area = 2.957, 95%CI: 2.255 3.877, Unwilling: ORnear central urban area = 1.687, 95%CI: 1.230 2.313. ORcentralurbanarea = 2.218, 95%CI: 1.626 3.027), and convenient for movement (hesitancy: ORyes = 0.494, 95%CI: 0.420 0.580, Unwilling: ORyes = 0.585, 95%CI: 0.480 0.713), understanding of the free vaccine policy (hesitancy: ORunderstand = 0.204, 95%CI: 0.171 0.245, Unwilling: ORunderstand = 0.164, 95%CI: 0.128 0.210), influenza knowledge level≥ 13 points (hesitancy: OR≥13points = 0.628, 95%CI: 0.533 0.739, Unwilling: OR≥13points = 0.538, 95%CI: 0.437 0.662), influenza vaccine knowledge level≥ 12 points (hesitancy: OR≥12points = 0.422, 95%CI: 0.350 0.508, Unwilling: OR≥12points = 0.370, 95%CI: 0.290 0.472), and social trust level ≥ 12 points (hesitancy: OR≥12points = 0.134, 95%CI: 0.112 0.160, Unwilling: OR≥12points = 0.220, 95%CI: 0.180 0.269) are more willing to receive free influenza vaccine.Conclusion: The proportion of elderly people aged 70 and above who are willing to receive free influenza vaccine is high in Hangzhou. But the level of knowledge about influenza, vaccine and trust in society is low. The government should continue to improve the elderly's awareness and trust in society through medical staff, family members, television and radio media, and guide the elderly to actively vaccinate against influenza. Effective publicity should be carried out through the above channels to guide the elderly to actively vaccinate against influenza.

22 May 2019 in Human Vaccines & Immunotherapeutics
Verified
Journal Article
Closed access
YXYuyang Xu
Yuyang Xu
EXErping Xu
Erping Xu
SLShijun Liu
Shijun Liu
WZWei Zheng
Wei Zheng
XZXuechao Zhang
Xuechao Zhang
YLyan liu
yan liu
Objective: To delineate seroepidemiology of pertussis in Hangzhou, to evaluate the protection levels of pertussis among healthy populations, for improving prevention strategy of pertussis.Methods: During 2009–2017, a multistage stratified random sampling method was employed to select participants included via physical examination for subjects in several Community Health Centers in Hangzhou. Enzyme-Linked Immunosorbent Assay (ELISA) was used to detect Immunoglobulin G (IgG) antibodies against pertussis in serum samples. Results were compared among 11 age groups. Univariate and multivariate analysis were used to analyze the associations among the rates of pertussis IgG seropositivity and the geometric mean concentration (GMC) levels of pertussis IgG and the related factors.Results: A total of 3360 subjects with available information were included, with 1745 male and 1615 female. Of these, 59.6% subjects had a clear immunization history of diphtheria–tetanus–pertussis vaccine (DTP). The vaccination rates of DTP had a declined trend with older age. The rate of pertussis IgG seropositivity was 69.9% (95% confidence interval: 68.3–71.5) and the GMC for pertussis IgG was 48.46 U/ml. Significantly higher seropositivity and GMC for pertussis IgG were found in subjects that had inoculation vaccine history or unknown history when compared those without inoculation of vaccine, lower in age groups <10, 20–29, and 30–39 y when compared to the other age groups evaluated.Conclusions: There are different distribution profiles both of the seropositivity and GMC for pertussis IgG for different age groups and immunization history of vaccine groups. In order to prevent pertussis occurrence, it is important to employ a booster dose of pertussis vaccine in adolescents and adults.

2 October 2020 in Expert Review of Vaccines
Verified
Journal Article
Closed access
YXYuyang Xu
Yuyang Xu
CJchai ji
chai ji
YLyan liu
yan liu
MLMingyan Li
Mingyan Li
DYDan Yao
Dan Yao
JCJunfang Chen
Junfang Chen
Objectives More and more premature infants were born worldwide that are suffering from various complications, vaccination for whom is often delayed in China. We aim to describe current vaccination recommendations in practice, immunization status, and vaccination safety for premature infants in Zhejiang. Methods The demographic information, medical records of treatments, and adverse events following immunization (AEFI) history were collected from infants' parents by questionnaire in the Vaccination Consultation Clinic(VCC). Vaccination data were retrieved from Zhejiang Provincial Immunization Information System. The information of AEFI was collected from the Chinese National Adverse Event Following Immunization Information System. Results A total of 1515 premature infants visiting the VCC were included in the study. The majority (65.94%) of them were under 7 months. 47.59% of premature infants were advised to receive normal vaccinations, while 45.94% were advised to defer a specific vaccination and 6.47% were advised to defer all vaccinations. A total of 807 infants received 7187 vaccine doses were administered and only seven cases experienced mild and self-limiting adverse reactions (9.74/10,000). No uncommon or serious side effects were reported. Conclusion Most premature infants visiting the VCC did not receive vaccines on time. The majority of them can be safely vaccinated according to the national-recommended schedule.

22 September 2020 in Human Vaccines & Immunotherapeutics
Verified
Journal Article
Closed access
XCXinren Che
Xinren Che
YLyan liu
yan liu
JWJun Wang
Jun Wang
YXYuyang Xu
Yuyang Xu
XZXuechao Zhang
Xuechao Zhang
XZXiaoping Zhang
Xiaoping Zhang
Although China’s Expanded Program on Immunization (EPI) provides two doses of group A meningococcal polysaccharide vaccine (MPV-A) for children younger than 2 y, more self-paying group A and group ...