Grace W.K. Tang
University of Hong Kong
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Grace W.K. Tang.
The Lancet | 2007
Elmar A. Joura; Sepp Leodolter; Mauricio Hernandez-Avila; Cosette M. Wheeler; Gonzalo Perez; Laura A. Koutsky; Suzanne M. Garland; Diane M. Harper; Grace W.K. Tang; Daron G. Ferris; Marc Steben; Ronald W. Jones; Janine T. Bryan; Frank J. Taddeo; Oliver M. Bautista; Mark T. Esser; Heather L. Sings; Micki Nelson; John W. Boslego; Carlos Sattler; Eliav Barr; Jorma Paavonen
BACKGROUND Vulval and vaginal cancers among younger women are often related to infection with human papillomavirus (HPV). These cancers are preceded by high-grade vulval intraepithelial neoplasia (VIN2-3) and vaginal intraepithelial neoplasia (VaIN2-3). Our aim was to do a combined analysis of three randomised clinical trials to assess the effect of a prophylactic quadrivalent HPV vaccine on the incidence of these diseases. METHODS 18 174 women (16-26 years) were enrolled and randomised to receive either quadrivalent HPV6/11/16/18 L1 virus-like-particle vaccine or placebo at day 1, and months 2 and 6. Individuals underwent detailed anogenital examination at day 1, 1 month after dose three, and at 6-12-month intervals for up to 48 months. Suspect genital lesions were biopsied and read by a panel of pathologists and vaccine HPV type-specific DNA testing was done. The primary endpoint was the combined incidence of VIN2-3 or VaIN2-3 associated with HPV16 or HPV18. Primary efficacy analyses were done in a per-protocol population. FINDINGS The mean follow-up time was 3 years. Among women naive to HPV16 or HPV18 through 1 month after dose three (per-protocol population; vaccine n=7811; placebo n=7785), the vaccine was 100% effective (95% CI 72-100) against VIN2-3 or VaIN2-3 associated with HPV16 or HPV18. In the intention-to-treat population (which included 18 174 women who, at day 1, could have been infected with HPV16 or HPV18), vaccine efficacy against VIN2-3 or VaIN2-3 associated with HPV16 or HPV18 was 71% (37-88). The vaccine was 49% (18-69) effective against all VIN2-3 or VaIN2-3, irrespective of whether or not HPV DNA was detected in the lesion. The most common treatment-related adverse event was injection-site pain. INTERPRETATION Prophylactic administration of quadrivalent HPV vaccine was effective in preventing high-grade vulval and vaginal lesions associated with HPV16 or HPV18 infection in women who were naive to these types before vaccination. With time, such vaccination could result in reduced rates of HPV-related vulval and vaginal cancers.
BMJ | 2010
Joakim Dillner; Susanne K. Kjaer; Cosette M. Wheeler; Kristján Sigurdsson; Ole Erik Iversen; Mauricio Hernandez-Avila; Gonzalo Perez; Darron R. Brown; Laura A. Koutsky; Eng Tay; Patricia J. 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; Elmar A. Joura; Slawomir Majewski; Nubia Muñoz; Evan R. Myers; Luisa L. Villa; Frank J. Taddeo; Christine Roberts; Amha Tadesse; Janine T. Bryan
Objectives To evaluate the prophylactic efficacy of the human papillomavirus (HPV) quadrivalent vaccine in preventing low grade cervical, vulvar, and vaginal intraepithelial neoplasias and anogenital warts (condyloma acuminata). Design Data from two international, double blind, placebo controlled, randomised efficacy trials of quadrivalent HPV vaccine (protocol 013 (FUTURE I) and protocol 015 (FUTURE II)). The trials were to be 4 years in length, and the results reported are from final study data of 42 months’ follow-up. Setting Primary care centres and university or hospital associated health centres in 24 countries and territories around the world. Participants 17 622 women aged 16-26 years enrolled between December 2001 and May 2003. Major exclusion criteria were lifetime number of sexual partners (>4), history of abnormal cervical smear test results, and pregnancy. Intervention Three doses of quadrivalent HPV vaccine (for serotypes 6, 11, 16, and 18) or placebo at day 1, month 2, and month 6. Main outcome measures Vaccine efficacy against cervical, vulvar, and vaginal intraepithelial neoplasia grade I and condyloma in a per protocol susceptible population that included subjects who received all three vaccine doses, tested negative for the relevant vaccine HPV types at day 1 and remained negative through month 7, and had no major protocol violations. Intention to treat, generally HPV naive, and unrestricted susceptible populations were also studied. Results In the per protocol susceptible population, vaccine efficacy against lesions related to the HPV types in the vaccine was 96% for cervical intraepithelial neoplasia grade I (95% confidence interval 91% to 98%), 100% for both vulvar and vaginal intraepithelial neoplasia grade I (95% CIs 74% to 100%, 64% to 100% respectively), and 99% for condyloma (96% to 100%). Vaccine efficacy against any lesion (regardless of HPV type) in the generally naive population was 30% (17% to 41%), 75% (22% to 94%), and 48% (10% to 71%) for cervical, vulvar, and vaginal intraepithelial neoplasia grade I, respectively, and 83% (74% to 89%) for condyloma. Conclusions Quadrivalent HPV vaccine provided sustained protection against low grade lesions attributable to vaccine HPV types (6, 11, 16, and 18) and a substantial reduction in the burden of these diseases through 42 months of follow-up. Trial registrations NCT00092521 and NCT00092534.
Cancer Prevention Research | 2009
Susanne K. Kjaer; Kristján Sigurdsson; Ole-Erik Iversen; Mauricio Hernandez-Avila; Cosette M. Wheeler; Gonzalo Perez; Darron R. Brown; Laura A. Koutsky; Eng Tay; Patricia J. 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 T. Bryan
Quadrivalent human papillomavirus (HPV) vaccine has been shown to provide protection from HPV 6/11/16/18–related cervical, vaginal, and vulvar disease through 3 years. We provide an update on the efficacy of the quadrivalent HPV vaccine against high-grade cervical, vaginal, and vulvar lesions based on end-of-study data from three clinical trials. Additionally, we stratify vaccine efficacy by several baseline characteristics, including age, smoking status, and Papanicolaou (Pap) test results. A total of 18,174 females ages 16 to 26 years were randomized and allocated into one of three clinical trials (protocols 007, 013, and 015). Vaccine or placebo was given at baseline, month 2, and month 6. Pap testing was conducted at regular intervals. Cervical and anogenital swabs were collected for HPV DNA testing. Examination for the presence of vulvar and vaginal lesions was also done. Endpoints included high-grade cervical, vulvar, or vaginal lesions (CIN 2/3, VIN 2/3, or VaIN 2/3). Mean follow-up time was 42 months post dose 1. Vaccine efficacy against HPV 6/11/16/18–related high-grade cervical lesions in the per-protocol and intention-to-treat populations was 98.2% [95% confidence interval (95% CI), 93.3-99.8] and 51.5% (95% CI, 40.6-60.6), respectively. Vaccine efficacy against HPV 6/11/16/18–related high-grade vulvar and vaginal lesions in the per-protocol and intention-to-treat populations was 100.0% (95% CI, 82.6-100.0) and 79.0% (95% CI, 56.4-91.0), respectively. Efficacy in the intention-to-treat population tended to be lower in older women, women with more partners, and women with abnormal Pap test results. The efficacy of quadrivalent HPV vaccine against high-grade cervical and external anogenital neoplasia remains high through 42 months post vaccination.
Vaccine | 2008
Elmar A. Joura; Susanne K. Kjaer; Cosette M. Wheeler; Kristján Sigurdsson; Ole Erik Iversen; Mauricio Hernandez-Avila; Gonzalo Perez; Darron R. Brown; Laura A. Koutsky; Eng Tay; Patricia J. 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; Xavier Bosch; Joakim Dillner; Robert J. Kurman; Slawomir Majewski; Nubia Muñoz; Evan R. Myers; Luisa L. Villa; Frank J. Taddeo; Christine Roberts; Amha Tadesse
The efficacy of the quadrivalent Human Papillomavirus (HPV) vaccine is thought to be mediated by humoral immunity. We evaluated the correlation between quadrivalent HPV vaccine-induced serum anti-HPV responses and efficacy. 17,622 women were vaccinated at day 1, and months 2 and 6. At day 1 and at 6-12 months intervals for up to 48 months, subjects underwent Papanicolaou and genital HPV testing. No immune correlate of protection could be found due to low number of cases. Although 40% of vaccine subjects were anti-HPV 18 seronegative at end-of-study, efficacy against HPV 18-related disease remained high (98.4%; 95% CI: 90.5-100.0) despite high attack rates in the placebo group. These results suggest vaccine-induced protection via immune memory, or lower than detectable HPV 18 antibody titers.
Human Vaccines | 2009
Sven Eric Olsson; Susanne K. Kjaer; Kristján Sigurdsson; Ole Erik Iversen; Mauricio Hernandez-Avila; Cosette M. Wheeler; Gonzalo Perez; Darron R. Brown; Laura A. Koutsky; Eng Tay; Patricia J. García; Kevin A. Ault; Suzanne M. Garland; Sepp Leodolter; 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 T. Bryan
Objective In the quadrivalent (types 6/11/16/18) HPV vaccine (GARDASIL®/SILGARD®) clinical program, 73% of women aged 16-26 were naïve to all vaccine HPV types. In these women, prophylactic administration of the vaccine was highly effective in preventing HPV 6/11/16/18-related cervical disease. Of the remaining women, 15% of had evidence of past infection with one or more vaccine HPV types (seropositive and DNA negative) at the time of enrollment. Here we present an analysis in this group of women to determine the efficacy of the HPV 6/11/16/18 vaccine against new cervical and external anogenital disease related to the same vaccine HPV type which had previously been cleared. Vaccine tolerability in this previously infected population was also assessed. Methods 18,174 women were enrolled into 3 clinical studies. The data presented comprise a subset of these subjects (n = 2,617) who were HPV seropositive and DNA negative at enrollment (for ≥1 vaccine type). In each study, subjects were randomized in a 1:1 ratio to receive HPV 6/11/16/18 vaccine or placebo at day 1, month 2 and month 6 (without knowledge of baseline HPV status). Procedures performed for efficacy data evaluation included detailed genital examination, Pap testing, and collection of cervicovaginal and external genital specimens. Analyses of efficacy were carried out in a population stratified by HPV serology and HPV DNA status at enrollment. Results Subjects were followed for an average of 40 months. Seven subjects in the placebo group developed cervical disease, and eight subjects developed external genital disease related to a vaccine HPV type they had previously encountered. No subject receiving HPV 6/11/16/18 vaccine developed disease to a vaccine HPV type to which they were seropositive and DNA negative at enrolment. Conclusions These results suggest that natural HPV infection-elicited antibodies may not provide complete protection over time, however the immune response to the HPV 6/11/16/18 vaccine appears to prevent reinfection or reactivation of disease with vaccine HPV types. Vaccine-related adverse experiences were higher among subjects receiving vaccine, mostly due to increased injection site adverse experiences.
Maturitas | 1994
Grace W.K. Tang
Chinese factory workers (427) mainly of Fujian origin were found to have few climacteric symptoms. Of these, 65% and 50% reported having no circulatory and nervosity symptoms, respectively. Only 18% of women experienced hot flushes. The climacteric symptoms were more pronounced at the perimenopausal period (P < 0.001) when these women experienced more irregular menstruation. Low socio-economic status and educational level did not have adverse effects on the symptom reporting. High parity and employment may be positive factors in this period of change of life. A majority of women (74%) felt that the climacteric and menopause is a natural process which caused them no concern. Of those who were still menstruating 80% did not anticipate that they would have problems with the climacteric and menopause. These womens different climacteric pattern could be related to their introspective abilities to cope adequately or in an impersonal manner.
Journal of Bone and Mineral Research | 2007
Annie W. C. Kung; Ka‐Kui Lee; Andrew Y. Y. Ho; Grace W.K. Tang; Keith D. K. Luk
Independent risk factors for osteoporotic fracture were identified for a Southern Chinese postmenopausal population. Clinical risk factor assessment with or without BMD measurement was shown to be an effective predictor of 10‐yr risk of osteoporotic fracture and provides a more accessible tool for patient evaluation.
Osteoporosis International | 1999
A. W. C. Kung; Keith D. K. Luk; Leung-Wing Chu; Grace W.K. Tang
Abstract: Quantitative ultrasound (QUS) is emerging as a simple, inexpensive and noninvasive method for assessing bone quality and assessing fracture risk. We assessed the usefulness of a contact calcaneal ultrasonometer by studying normal premenopausal women (group I, n= 53), normal postmenopausal women (group II, n= 198), and osteoporotic women without (group III, n= 141) and with vertebral fractures (group IV, n= 53). The osteoporotic subjects had a T-score of the spine or hip neck bone mineral density (BMD) <−2.5 based on the local Chinese peak young mean values. When compared with postmenopausal controls, mean broadband ultrasound attenuation (BUA), speed of sound (SOS), and quantitative ultrasound index (QUI) were 26%, 2.1% and 25% lower in women with vertebral fractures (p all <0.005). The correlation coefficients between QUS parameters and BMD of the spine and hip ranged between 0.4 and 0.5. The ability of the QUS to discriminate between patients groups was determined based on the mean value of normal premenopausal women in group I. The mean T-score for women with fractures was −2.87 ± 1.02 for BUA, −2.54 ± 0.79 for SOS, −3.17 ± 0.70 for QUI, −2.65 ± 0.86 for L2–4 BMD and −2.53 ± 0.66 for hip neck BMD. After adjustment for age and body mass index, the odds ratio of vertebral fracture was 1.71 (95% CI 1.2–2.6) for each 1 SD reduction in BUA, 2.72 (1.3–5.3) for SOS, 2.58 (1.4–4.6) for QUI, 2.33 (1.6–3.3) for L2–4 BMD, 2.09 (1.37–3.20) for femoral neck BMD and 1.88 (1.34–2.92) for total hip BMD. The association between the QUS parameters and vertebral fracture risk persisted even adjustment for BMD. The area under the receiver operating characteristic curve for BUA for vertebral fracture was 0.92, for SOS, QUI, L2–4 BMD and femoral neck BMD was 0.95, and for total hip was 0.91.
Osteoporosis International | 1999
A. W. C. Kung; Grace W.K. Tang; Keith D. K. Luk; Leung-Wing Chu
Abstract: Quantitative ultrasound (QUS) assessment at the calcaneus has been found to be a safe and reliable method for evaluating skeletal status. The present study aimed at evaluating the precision of the Sahara bone ultrasound densitometer and to determine the normative QUS data in healthy southern Chinese women. Broadband ultrasound attenuation (BUA), speed of sound (SOS) and qualitative ultrasound index (QUI) were determined. The long-term in vitro precision of the Sahara machine over 6 months was 4.6% for BUA and 0.39% for SOS. The short-term in vivo precision was 3.2 ± 1.3% for BUA, 0.3 ± 0.2% for SOS and 1.8 ± 1.0% for QUI. The standardized precision for BUA, SOS and QUI was 4.4, 3.8 and 2.2 respectively. The normative data were determined in 1086 healthy subjects. Postmenopausal women had significantly lower BUA, SOS and QUI levels than the premenopausal women. Significant negative correlations were observed between QUS indices and age. Bone mineral density (BMD) assessments was performed on 349 of these subjects. BUA correlated significantly with lumbar spine BMD (r; = 0.326) and femoral neck BMD (r= 0.395). Similar correlations were observed between SOS, QUI and BMD, with r values ranging between 0.446 to 0.522. Despite the fact that Chinese women have significantly lower BMD values than Caucasian women, the mean BUA values for pre- and postmenopausal Chinese women (73 ± 18 and 59 ± 18 dB/MHz respectively) were almost the same as those reported for Caucasian womeo. These normative data will be useful in the assessment of southern Chinese women with fracture risk.
Clinical and Vaccine Immunology | 2007
Suzanne M. Garland; Marc Steben; Mauricio Hernandez-Avila; Laura A. Koutsky; Cosette M. Wheeler; Gonzalo Perez; Diane M. Harper; Sepp Leodolter; Grace W.K. Tang; Daron G. Ferris; Mark T. Esser; Scott Vuocolo; Micki Nelson; Radha Railkar; Carlos Sattler; Eliav Barr
ABSTRACT The incorporation of multiple antigens into a single human papillomavirus (HPV) vaccine may induce immune interference. To evaluate whether interference occurs when HPV type 16 (HPV16) virus-like particles are combined in a multivalent vaccine, we conducted a study to evaluate anti-HPV16 responses among subjects receiving three-dose regimens of either a monovalent HPV16 vaccine or a quadrivalent HPV (types 6, 11, 16, and 18) vaccine.