SummaryBackgroundAn increase in worldwide HPV vaccination could be facilitated if fewer than three doses of vaccine are as effective as three doses. We originally aimed to compare the immunogenicity and frequency of persistent infection and cervical precancerous lesions caused by vaccine-targeted HPV after vaccination with two doses of quadrivalent vaccine on days 1 and 180 or later, with three doses on days 1, 60, and 180 or later, in a cluster-randomised trial. Suspension of the recruitment and vaccination due to events unrelated to our study meant that some enrolled girls could not be vaccinated and some vaccinated girls received fewer than the planned number of vaccinations by default. As a result, we re-analysed our data as an observational cohort study.MethodsOur study was designed to be done in nine locations (188 clusters) in India. Participants were unmarried girls aged 10–18 years vaccinated in four cohorts: girls who received three doses of vaccine on days 1, 60, and 180 or later, two doses on days 1 and 180 or later, two doses on days 1 and 60 by default, and one dose by default. The primary outcomes were immunogenicity in terms of L1 genotype-specific binding antibody titres, neutralising antibody titres, and antibody avidity after vaccination for the vaccine-targeted HPV types 16, 18, 6, and 11 and incident and persistent infections with these HPVs. Analysis was per actual number of vaccine doses received. This study is registered with ISRCTN, number ISRCTN98283094; and with ClinicalTrials.gov, number NCT00923702.FindingsVaccination of eligible girls was initiated on Sept 1, 2009, and continued until April 8, 2010. Of 21 258 eligible girls identified at 188 clusters, 17 729 girls were recruited from 178 clusters before suspension. 4348 (25%) girls received three doses, 4979 (28%) received two doses on days 1 and 180 or later, 3452 (19%) received two doses at days 1 and 60, and 4950 (28%) received one dose. Immune response in the two-dose HPV vaccine group was non-inferior to the three-dose group (median fluorescence intensity ratio for HPV 16 1·12 [95% CI 1·02–1·23] and for HPV 18 1·04 [0·92–1·19]) at 7 months, but was inferior in the two-dose default (0·33 [0·29–0·38] for HPV 16 and 0·51 [0·43–0·59] for HPV 18) and one-dose default (0·09 [0·08–0·11] for HPV 16 and 0·12 [0·10–0·14] for HPV 18) groups at 18 months. The geometric mean avidity indices after fewer than three doses by design or default were non-inferior to those after three doses of vaccine. Fewer than three doses by design and default induced detectable concentrations of neutralising antibodies to all four vaccine-targeted HPV types, but at much lower concentration after one dose. Cervical samples from 2649 participants were tested and the frequency of incident HPV 16, 18, 6, and 11 infections was similar irrespective of the number of vaccine doses received. The testing of at least two samples from 838 participants showed that there was no persistent HPV 16 or 18 infections in any study group at a median follow-up of 4·7 years (IQR 4·2–...
We evaluated a 'see and treat' procedure involving screening, colposcopy, biopsy and cryotherapy by trained nurses in one-visit in field clinics in a cervical screening study in South India for its acceptability, safety and effectiveness in curing cervical intraepithelial neoplasia (CIN). Women positive on visual inspection with acetic acid (VIA) were advised colposcopy, directed biopsies and cryotherapy if they had colposcopic impression of CIN in one visit by nurses in field clinics supervised by a doctor. Side effects and complications were assessed and cure rates were evaluated with VIA, colposcopy and biopsy if colposcopic abnormalities were suspected. Cure was defined as no clinical or histological evidence of CIN at X6 months from treatment. Of the 2513 women offered 'see and treat' procedure, 1879 (74.8%) accepted. Of the 1397 women with histologically proved CIN treated with cryotherapy, 1026 reported for follow-up evaluation. Cure rates were 81.4% (752 out of 924) for women with CIN 1; 71.4% (55 out of 77) for CIN 2 and 68.0% (17 out of 25) for CIN 3. Minor side effects and complications were documented in less than 3% of women. 'See and treat' with cryotherapy by nurses under medical supervision is acceptable, safe and effective for cervical cancer prevention in low-resource settings.
Our results indicate that a single dose of quadrivalent HPV vaccine is immunogenic and provides lasting protection against HPV 16 and 18 infections similar to the three- and two-dose vaccine schedules, although the study suffer from some limitations. Data on long term protection beyond 7 years against HPV infection and cervical precancerous lesions are needed before policy guidelines regarding a single dose can be formulated and implemented. Significant and long-lasting protective effect of a single dose can be a strong argument to introduce one dose of the HPV vaccine in many low income countries where the current standard of care for cervical cancer prevention is 'no intervention'.
Background: India shows some of the highest rates of cervical cancer worldwide, and more than 70% of the population is living in rural villages. Prospective cohort studies to determine the risk factors for cervical cancer are very rare from low and medium resource countries. The aim of this study was to quantify the effect of risk factors related to cervical cancer in a rural setting in South India. Material and methods: Sociodemographic and reproductive potential risk factors for cervical cancer were studied using the data from a cohort of 30,958 women who constituted the unscreened control group in a randomised screening trial in Dindigul district, Tamilnadu, India. The analysis was accomplished with the Cox proportional hazard regression model. Results: Women of increasing age (HR=2.4; 95% CI: 1.6, 3.8 in 50-59 vs 30-39), having many pregnancies (HR=7.1; 1.0, 52 in 4+ vs 0) and no education (HR=0.6; 0.2, 0.7 in high vs none) were found to be at significantly increased risk of cervical cancer. Conclusion: This cohort study gives very strong evidence to say that education is the fundamental factor among the sociodemographic and reproductive determinants of cervical cancer in low resource settings. Public awareness through education and improvements in living standards can play an important role in reducing the high incidence of cervical cancer in India. These findings further stress the importance of formulating public health policies aimed at increasing awareness and implementation of cervical cancer screening programmes.
Cervical cancer is a major cause of mortality and premature death among women in their most productive years in low- and medium-resourced countries in Asia, Africa and Latin America, despite the fact that it is an eminently preventable cancer. While cytology screening programmes have resulted in a substantial reduction of cervical cancer mortality in developed countries, they have been shown to have a wide range of sensitivity in most routine settings including in developing countries. Although liquid-based cytology improves sample adequacy, claims on improved sensitivity remain controversial. Human papillomavirus testing is more sensitive than cytology, but whether this gain represents protection against future cervical cancer is not clear. Recently, in a randomized trial, the use of visual inspection with 4% acetic acid was shown to reduce cervical cancer incidence and mortality. Cryotherapy and large loop excision of the transformation zone are effective and safe treatment methods for cervical intraepithelial neoplasia. The clinical stage of cancer is the single most important prognostic factor and should be carefully evaluated in choosing optimal treatment between surgery and radiotherapy, with or without chemotherapy. At the public health level, health care infrastructure, affordability and capacity for initiating and sustaining vaccination and screening programmes are critical factors in cervical cancer control. On the other hand, an informed practitioner can utilize the multiple opportunities in routine primary care interactions for prevention, screening, early detection and prompt referral for treatment.
Extending two-dose recommendations of HPV vaccine to girls between 15 and 18 years will reduce program cost and improve compliance. Immunogenicity and vaccine targeted HPV infection outcomes were compared between 1795 girls aged 15–18 years receiving two (1–180 days) and 1515 girls of same age receiving three (1–60–180 days) doses. Immunogenicity outcomes in 15–18 year old two-dose recipients were also compared with the 10–14 year old three-dose (N = 2833) and two-dose (N = 3184) recipients. The 15–18 year old two-dose recipients had non-inferior L1-binding antibody titres at seven months against vaccine-targeted HPV types compared to three-dose recipients at 15–18 years and three-dose recipients at 10–14 years of age. Neutralizing antibody titres at 18 months in 15–18 year old two-dose recipients were non-inferior to same age three-dose recipients for all except HPV 18. The titres were inferior to those in the 10–14 year old three-dose recipients for all targeted types. Frequency of incident infections from vaccine-targeted HPV types in the 15–18 year old two-dose recipients was similar to the three dose recipients. None of the girls receiving two or three doses had persistent infection from vaccine-targeted types. These findings support that two doses of HPV vaccine can be extended to girls aged 15–18 years.
Earlier publication from the ongoing multi-centric study of the International Agency for Research on Cancer to evaluate less than three doses of the quadrivalent Human Papillomavirus (HPV) vaccine in India amongst unmarried girls demonstrated non-inferior total antibody titres, neutralizing antibody titres and antibody avidity in 2-dose recipients compared to 3-dose recipients at 15–18 years of age (Bhatla et al., 2018) [7]. The number of participants recruited at 15–18 years of age was 1515 and 1795 in the 3-dose and the 2-dose groups respectively. At a median follow-up of 7 years, incident HPV 16/18 infections were detected in 1.6% women receiving two doses and 0.8% women receiving three doses at 15–18 years. Frequency of incident infection was 7.0% in the age- and site-matched unvaccinated women (N = 1484). No persistent infection from HPV 16 was observed in the 2- or 3-dose recipients and one (0.2%) persistent HPV 18 infection was documented, each in the 3-dose and 2-dose cohorts. Among the unvaccinated women, the frequency of HPV 16/18 persistent infection was 1.7%. The protection offered by two doses of quadrivalent HPV vaccine against incident and persistent infections in recipients at 15–18 years is comparable to that seen in 3-dose recipients at 15–18 years.
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