Secondhand tobacco smoke exposure in homes and vehicles in youth: disparities among racial, and sexual and gender minorities.

Background: Secondhand smoke exposure (SHSe) among youth is a serious public health concern, leading to an increased risk of conditions such as asthma and respiratory infections. However, there is little research on SHSe among vulnerable populations, such as racial and sexual minorities. Understanding the factors associated with youth SHSe in homes and vehicles is crucial to developing better protective policies. Methods: This study utilized 2020 data from the National Youth Tobacco Survey, a representative sample of middle- and high-school students in the US. The primary outcomes were youth SHSe at home and while riding in a vehicle. Multinomial regression models were used to assess factors associated with SHSe. Results: The data included 9,912 students enrolled in grades 6 through 12 in the United States who reported never using any form of tobacco. Non-Hispanic Black students living with someone who does not use any form of tobacco products were significantly more likely to experience moderate [OR = 2.1 (1.1-3.9), p = 0.03] and severe [OR = 5.1 (2.2-11.7), p < 0.001] secondhand smoke exposure (SHSe) in homes compared to their non-Hispanic White counterparts. Heterosexual female students had lower odds of reporting moderate SHSe in the home compared to heterosexual males [OR = 0.7 (0.6-0.99), p = 0.02], whereas bisexual females had two-fold increased odds of severe SHSe in homes [OR = 2.0 (1.2-3.4), p = 0.01]. Conclusion: Significant efforts are needed to develop targeted interventions to reduce SHSe in homes and vehicles, particularly in these vulnerable populations.

Culturally Competent Education and Human Papillomavirus Self-Sampling Achieves Healthy People 2030 Cervical Screening Target Among Low-Income Non-Hispanic Black and Hispanic Women.

PURPOSE: Disparities in cervical cancer screening, incidence, and mortality exist in the United States. Cervical cancer incidence and mortality rates in Texas are 20% and 32% higher, respectively, than national averages. Within Texas, these rates are significantly higher among non-Hispanic (NH) Black and Hispanic women. Cervical cancer screening uptake is lower among NH Black and Hispanic women (72.9% and 75.9%, respectively) compared with White women (85.5%) in Texas. METHODS: During March-August 2023, we conducted a pilot study that offered culturally competent education and human papillomavirus (HPV) self-sampling kits to women in two public housing projects in Houston, TX, that have predominantly NH Black or Hispanic residents. Among those eligible for cervical cancer screening, 35% (n = 24) of the NH Black and 34% (n = 16) of the Hispanic women were found to be underscreened per the US Preventive Services Task Force Guideline. We recruited 40 (24 NH Black and 16 Hispanic) eligible women for our study. The study was approved by the MD Anderson institutional review board and registered with ClinicalTrials.gov (NCT04614155-March 11, 2020). RESULTS: Seventy-five percent of the NH Black and 87% of the Hispanic participants completed the HPV self-sampling procedures per protocol. Samples of 17% NH Black and 12% Hispanic participants showed a performance error. Overall, cervical cancer screening uptake improved from 65% to 91% among NH Black and from 66% to 96% among Hispanic participants. CONCLUSION: Culturally competent education and HPV self-sampling resulted in remarkable improvement in cervical cancer screening uptake among underscreened NH Black and Hispanic women residents of Houston public housing projects. Implementing this strategy could significantly reduce cervical cancer incidence and mortality among similar populations in the United States and globally.

Evaluation of immune response to single dose of quadrivalent HPV vaccine at 10-year post-vaccination.

BACKGROUND: The recent World Health Organization recommendation supporting single-dose of HPV vaccine will significantly reduce programmatic cost, mitigate the supply shortage, and simplify logistics, thus allowing more low- and middle-income countries to introduce the vaccine. From a programmatic perspective the durability of protection offered by a single-dose will be a key consideration. The primary objectives of the present study were to determine whether recipients of a single-dose of quadrivalent HPV vaccine had sustained immune response against targeted HPV types (HPV 6,11,16,18) at 10 years post-vaccination and whether this response was superior to the natural antibody titres observed in unvaccinated women. METHODS: Participants received at age 10-18 years either one, two or three doses of the quadrivalent HPV vaccine. Serology samples were obtained at different timepoints up to 10 years after vaccination from a convenience sample of vaccinated participants and from age-matched unvaccinated women at one timepoint. The evolution of the binding and neutralizing antibody response was presented by dose received. 10-year durability of immune responses induced by a single-dose was compared to that after three doses of the vaccine and in unvaccinated married women. RESULTS: The dynamics of antibody response among the single-dose recipients observed over 120 months show stabilized levels 18 months after vaccination for all four HPV types. Although the HPV type-specific (binding or neutralizing) antibody titres after a single-dose were significantly inferior to those after three doses of the vaccine (lower bounds of GMT ratios < 0.5), they were all significantly higher than those observed in unvaccinated women following natural infections (GMT ratios: 2.05 to 4.04-fold higher). The results correlate well with the high vaccine efficacy of single-dose against persistent HPV 16/18 infections reported by us earlier at 10-years post-vaccination. CONCLUSION: Our study demonstrates the high and durable immune response in single-dose recipients of HPV vaccine at 10-years post vaccination.

Financial Toxicities Persist for Cancer Survivors Irrespective of Current Cancer Status: An Analysis of Medical Expenditure Panel Survey.

This study estimates the out-of-pocket (OOP) expenditures for different cancer types among survivors with current vs no current cancer condition and across sex, which is understudied in the literature. This is a cross-sectional study of Medical Expenditure Panel Survey data for 2009-2018 where the primary outcome was the average per year OOP expenditure incurred by cancer survivors. Of 189 285 respondents, 15 010 (7.93%) were cancer survivors; among them, 46.28% had a current cancer condition. Average per year OOP expenditure for female survivors with a current condition of breast cancer ($1730), lung cancer ($1679), colon cancer ($1595), melanoma ($1783), non-Hodgkin lymphoma ($1656), nonmelanoma/other skin cancer (NMSC, $2118) and two or more cancers ($2310) were significantly higher than that of women with no history of cancer ($853, all P < .05). Similarly, average per year OOP expenditure for male survivors with a current condition of prostate cancer ($1457), lung cancer ($1131), colon cancer ($1471), melanoma ($1474), non-Hodgkin's lymphoma ($1653), NMSC ($1789), and bladder cancer ($2157) were significantly higher compared with the men with no history of cancer ($621, all P < .05). These differences persisted in survivors with no current cancer condition for breast cancer among women; prostate, lung, colon, and bladder cancer among men; and melanoma, NMSC, and two or more cancers among both sexes. OOP expenditure varied across cancer types and by sex for survivors with and without a current cancer condition. These findings highlight the need for targeted interventions for cancer survivors.

Secondary Prevention of Cervical Cancer: ASCO Resource-Stratified Guideline Update.

PURPOSE: To update resource-stratified, evidence-based recommendations on secondary prevention of cervical cancer globally. METHODS: American Society of Clinical Oncology convened a multidisciplinary, multinational Expert Panel to produce recommendations reflecting four resource-tiered settings. A review of existing guidelines, formal consensus-based process, and modified ADAPTE process to adapt existing guidelines was conducted. Other experts participated in formal consensus. RESULTS: This guideline update reflects changes in evidence since the previous update. Five existing guidelines were identified and reviewed, and adapted recommendations form the evidence base. Cost-effectiveness analyses provided indirect evidence to inform consensus, which resulted in ≥ 75% agreement. RECOMMENDATIONS: Human papillomavirus (HPV) DNA testing is recommended in all resource settings; visual inspection with acetic acid may be used in basic settings. Recommended age ranges and frequencies vary by the following setting: maximal: age 25-65 years, every 5 years; enhanced: age 30-65 years, if two consecutive negative tests at 5-year intervals, then every 10 years; limited: age 30-49 years, every 10 years; basic: age 30-49 years, one to three times per lifetime. For basic settings, visual assessment is used to determine treatment eligibility; in other settings, genotyping with cytology or cytology alone is used to determine treatment. For basic settings, treatment is recommended if abnormal triage results are obtained; in other settings, abnormal triage results followed by colposcopy is recommended. For basic settings, treatment options are thermal ablation or loop electrosurgical excision procedure; for other settings, loop electrosurgical excision procedure or ablation is recommended; with a 12-month follow-up in all settings. Women who are HIV-positive should be screened with HPV testing after diagnosis, twice as many times per lifetime as the general population. Screening is recommended at 6 weeks postpartum in basic settings; in other settings, screening is recommended at 6 months. In basic settings without mass screening, infrastructure for HPV testing, diagnosis, and treatment should be developed.Additional information is available at www.asco.org/resource-stratified-guidelines.

Vaccine efficacy against persistent human papillomavirus (HPV) 16/18 infection at 10 years after one, two, and three doses of quadrivalent HPV vaccine in girls in India: a multicentre, prospective, cohort study.

BACKGROUND: A randomised trial designed to compare three and two doses of quadrivalent human papillomavirus (HPV) vaccine in adolescent girls in India was converted to a cohort study after suspension of HPV vaccination in trials by the Indian Government. In this Article, the revised aim of the cohort study was to compare vaccine efficacy of single dose to that of three and two doses in protecting against persistent HPV 16 and 18 infection at 10 years post vaccination. METHODS: In the randomised trial, unmarried girls aged 10-18 years were recruited from nine centres across India and randomly assigned to either two doses or three doses of the quadrivalent HPV vaccine (Gardasil [Merck Sharp & Dohme, Whitehouse Station, NJ, USA]; 0·5 mL administered intramuscularly). After suspension of recruitment and vaccination, the study became a longitudinal, prospective cohort study by default, and participants were allocated to four cohorts on the basis of the number vaccine doses received per protocol: the two-dose cohort (received vaccine on days 1 and 180 or later), three-dose cohort (days 1, 60, and 180 or later), two-dose default cohort (days 1 and 60 or later), and the single-dose default cohort. Participants were followed up yearly. Cervical specimens were collected from participants 18 months after marriage or 6 months after first childbirth, whichever was earlier, to assess incident and persistent HPV infections. Married participants were screened for cervical cancer as they reached 25 years of age. Unvaccinated women age-matched to the married vaccinated participants were recruited to serve as controls. Vaccine efficacy against persistent HPV 16 and 18 infections (the primary endpoint) was analysed for single-dose recipients and compared with that in two-dose and three-dose recipients after adjusting for imbalance in the distribution of potential confounders between the unvaccinated and vaccinated cohorts. This trial is registered with ISRCTN, ISRCTN98283094, and ClinicalTrials.gov, NCT00923702. FINDINGS: Vaccinated participants were recruited between Sept 1, 2009, and April 8, 2010 (date of vaccination suspension), and followed up over a median duration of 9·0 years (IQR 8·2-9·6). 4348 participants had three doses, 4980 had two doses (0 and 6 months), and 4949 had a single dose. Vaccine efficacy against persistent HPV 16 and 18 infection among participants evaluable for the endpoint was 95·4% (95% CI 85·0-99·9) in the single-dose default cohort (2135 women assessed), 93·1% (77·3-99·8) in the two-dose cohort (1452 women assessed), and 93·3% (77·5-99·7) in three-dose recipients (1460 women assessed). INTERPRETATION: A single dose of HPV vaccine provides similar protection against persistent infection from HPV 16 and 18, the genotypes responsible for nearly 70% of cervical cancers, to that provided by two or three doses. FUNDING: Bill & Melinda Gates Foundation.

Evaluating the Performance of Hybrid Capture 2 Test as a Primary Screening Test from Studies Conducted in Low and Middle-Income Country Settings- Special Focus India.

Among the screening tests for cervical cancer, advantages of screening with second generation molecular Hybrid Capture 2 (HC2) test is the high sensitivity and negative predictive value that makes it easy to implement as a cervical cancer screening policy necessitating less screening rounds. High income countries are now implementing HC2 test in their national cervical cancer screening program. Since the acceptance of any screening test depends on the sensitivity of the test, the current study was carried out to evaluate the sensitivity of HC2 test reported from Low- and Middle-income countries (LMIC) which share major burden of cervical cancer globally and to establish if HC2 test could be used as a primary screening test in India. MATERIALS AND METHODS: The population based cross sectional studies from LMICs which evaluated HC2 test as a primary screening modality to diagnose Cervical intraepithelial neoplasm grade 2 and above (CIN2+) lesions were included. RESULTS: A total of 18 studies from LMIC involving 1,13,086 women were reviewed for sensitivity of HC2 as a primary screening test. The overall average sensitivity and specificity to diagnose CIN2+ lesions were 79.84% (95% CI-71.01,86.73) and 85.63% (95% CI- 84.37,86.92) respectively. India demonstrated an average sensitivity and specificity of 65% (95% CI 57,77) and 93% (95% CI- 92,94) respectively. CONCLUSION: Results from LMIC demonstrate a comparably low sensitivity of HC2 test to diagnose CIN2+ lesions as compared to that reported from High income countries. Sensitivity of HC2 was substantially low for India. The current study discusses issues of HC2 assay and the role of untreated Reproductive tract infections as probable causes for low sensitivity of the test. This needs further research in an attempt to improve the sensitivity of the test in an era of self-sampling and low-cost HPV test on horizon to improve the coverage for cervical cancer.
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Effect of screening by clinical breast examination on breast cancer incidence and mortality after 20 years: prospective, cluster randomised controlled trial in Mumbai.

OBJECTIVE: To test the efficacy of screening by clinical breast examination in downstaging breast cancer at diagnosis and in reducing mortality from the disease, when compared with no screening. DESIGN: Prospective, cluster randomised controlled trial. SETTING: 20 geographically distinct clusters located in Mumbai, India, randomly allocated to 10 screening and 10 control clusters; total trial duration was 20 years (recruitment began in May 1998; database locked in March 2019 for analysis). PARTICIPANTS: 151 538 women aged 35-64 with no history of breast cancer. INTERVENTIONS: Women in the screening arm (n=75 360) received four screening rounds of clinical breast examination (conducted by trained female primary health workers) and cancer awareness every two years, followed by five rounds of active surveillance every two years. Women in the control arm (n=76 178) received one round of cancer awareness followed by eight rounds of active surveillance every two years. MAIN OUTCOME MEASURES: Downstaging of breast cancer at diagnosis and reduction in mortality from breast cancer. RESULTS: Breast cancer was detected at an earlier age in the screening group than in the control group (age 55.18 (standard deviation 9.10) v 56.50 (9.10); P=0.01), with a significant reduction in the proportion of women with stage III or IV disease (37% (n=220) v 47% (n=271), P=0.001). A non-significant 15% reduction in breast cancer mortality was observed in the screening arm versus control arm in the overall study population (age 35-64; 20.82 deaths per 100 000 person years (95% confidence interval 18.25 to 23.97) v 24.62 (21.71 to 28.04); rate ratio 0.85 (95% confidence interval 0.71 to 1.01); P=0.07). However, a post hoc subset analysis showed nearly 30% relative reduction in breast cancer mortality in women aged 50 and older (24.62 (20.62 to 29.76) v 34.68 (27.54 to 44.37); 0.71 (0.54 to 0.94); P=0.02), but no significant reduction in women younger than 50 (19.53 (17.24 to 22.29) v 21.03 (18.97 to 23.44); 0.93 (0.79 to 1.09); P=0.37). A 5% reduction in all cause mortality was seen in the screening arm versus the control arm, but it was not statistically significant (rate ratio 0.95 (95% confidence interval 0.81 to 1.10); P=0.49). CONCLUSIONS: These results indicate that clinical breast examination conducted every two years by primary health workers significantly downstaged breast cancer at diagnosis and led to a non-significant 15% reduction in breast cancer mortality overall (but a significant reduction of nearly 30%in mortality in women aged ≥50). No significant reduction in mortality was seen in women younger than 50 years. Clinical breast examination should be considered for breast cancer screening in low and middle income countries. TRIAL REGISTRATION: Clinical Trials Registry of India CTRI/2010/091/001205; ClinicalTrials.gov NCT00632047.

Acquisition, prevalence and clearance of type-specific human papillomavirus infections in young sexually active Indian women: A community-based multicentric cohort study.

In context of the ongoing multi-centric HPV vaccine study in India, unvaccinated married women (N = 1484) aged 18-23 years were recruited in 2012-2015 as age-matched controls to the vaccinated women and followed up yearly. We assess type-specific prevalence, natural history and potential determinants of human papillomavirus (HPV) infection in these unvaccinated women. Cervical samples were collected yearly for at least four consecutive years. A Multiplex Type-Specific E7-Based polymerase chain reaction assay was used to detect 21 HPV types. HPV prevalence was 36.4% during 6 years. Most common HPV types were 16 (6.5%) and 31 (6.1%). Highest persistence were observed for HPV 35 (62.5%) and 52 (25%). New HPV acquisition rate was 5.6/1000 person-months of observation (PMO), highest for HPV 16 (1.1/1000 PMO). Type-specific clearance rates ranged between 2.9-5.5/100 PMO. HPV 16 and/or 18 infections were 41% (95% CI 4-63%) lower among women with 2-<3 years between marriage and first cervical sample collection compared to those with <2 years. HPV prevalence and acquisition rates in young Indian women were lower than their Western counterparts. HPV 16 infections being most common shows the importance and potential impact of HPV vaccination in India. Women with 2-3 years exposure had reduced risk possibly due to higher infections clearance.

Reliability of conventional Papanicolaou smear in diagnosing bacterial vaginosis among women with clinical genital infection.

OBJECTIVE: Bacterial vaginosis (BV) is a common reproductive tract infection (RTI) reported among Indian women. BV can influence the persistence of high-risk oncogenic human papillomavirus, a causative factor for cervical cancer. BV and cervical cancer are major public health issues in a developing country like India. It becomes important for a resource-constrained country like India with poor healthcare access to implement control measures to screen and treat RTI in an attempt to prevent the risk for cervical cancer. Papanicolaou (Pap) smear is an established screening tool for cervical cancer and the diagnosis of RTIs, forms a part of its evaluation. The present study explores the validity of conventional Pap smear in diagnosing BV. METHODOLOGY: Pap smear and Gram stain smear were collected for 254 women with clinically evident cervicitis/cervicovaginitis (genital infection). Using the Nugent score on Gram stain as a gold standard, we determined the sensitivity and specificity of Pap smear to diagnose BV. RESULTS: The overall prevalence of BV in the study population was 44% using the Nugent score. Pap smear showed sensitivity and specificity of 70.9%. (CI- 61.5% - 79.2%) and 56.8% (CI - 48.2%-65.2%), respectively. The positive predictive value of Pap smear to diagnose BV was 56.5% (CI - 47.8%-64.9%), and the negative predictive value was 71.2% (CI - 61.8%-79.4%). CONCLUSION: In the present study, conventional Pap smear demonstrates good accuracy to detect BV. Pap testing for cervical cancer screening can additionally serve as an effective screening tool for diagnosing BV among women with genital infection in healthcare settings.

Two-dose recommendation for Human Papillomavirus vaccine can be extended up to 18 years - updated evidence from Indian follow-up cohort study.

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.

Secondary Prevention of Cervical Cancer: ASCO Resource-Stratified Clinical Practice Guideline.

PURPOSE: To provide resource-stratified, evidence-based recommendations on the secondary prevention of cervical cancer globally. METHODS: ASCO convened a multidisciplinary, multinational panel of oncology, primary care, epidemiology, health economic, cancer control, public health, and patient advocacy experts to produce recommendations reflecting four resource-tiered settings. A review of existing guidelines, a formal consensus-based process, and a modified ADAPTE process to adapt existing guidelines were conducted. Other experts participated in formal consensus. RESULTS: Seven existing guidelines were identified and reviewed, and adapted recommendations form the evidence base. Four systematic reviews plus cost-effectiveness analyses provided indirect evidence to inform consensus, which resulted in ≥ 75% agreement. RECOMMENDATIONS: Human papillomavirus (HPV) DNA testing is recommended in all resource settings; visual inspection with acetic acid may be used in basic settings. Recommended age ranges and frequencies by setting are as follows: maximal: ages 25 to 65, every 5 years; enhanced: ages 30 to 65, if two consecutive negative tests at 5-year intervals, then every 10 years; limited: ages 30 to 49, every 10 years; and basic: ages 30 to 49, one to three times per lifetime. For basic settings, visual assessment is recommended as triage; in other settings, genotyping and/or cytology are recommended. For basic settings, treatment is recommended if abnormal triage results are present; in other settings, colposcopy is recommended for abnormal triage results. For basic settings, treatment options are cryotherapy or loop electrosurgical excision procedure; for other settings, loop electrosurgical excision procedure (or ablation) is recommended. Twelve-month post-treatment follow-up is recommended in all settings. Women who are HIV positive should be screened with HPV testing after diagnosis and screened twice as many times per lifetime as the general population. Screening is recommended at 6 weeks postpartum in basic settings; in other settings, screening is recommended at 6 months. In basic settings without mass screening, infrastructure for HPV testing, diagnosis, and treatment should be developed.Additional information can be found at www.asco.org/rs-cervical-cancer-secondary-prev-guideline and www.asco.org/guidelineswiki.It is the view of of ASCO that health care providers and health care system decision makers should be guided by the recommendations for the highest stratum of resources available. The guideline is intended to complement, but not replace, local guidelines.

Improved Survival of Cervical Cancer Patients in a Screened Population in Rural India

Objectives: To describe the survival experience of cervix cancer patients in a screened rural population in India. Methods: Included 558 cervical cancer patients diagnosed in 2000-2013 in a cohort of 100,258 women invited for screening during 2000-2003. The primary end point was death from cervical cancer. We used the Kaplan-Meier method to estimate cumulative observed survival and Cox proportional hazards regression to assess the effect of patient characteristics on survival after diagnosis. Results: Of the 558 cases included, 143 (26%) and 114 (20%) were diagnosed in stages IA and IB respectively; 252 (45.2%) were dead, and 306 (54.8%) were alive at the last follow-up. The overall 5-year observed survival was 60.5%. The 5-year survival of stage IA patients was 95.1% and 5.3% for stage IV patients. All surgically treated stage IA patients, 94.1% of stage IB patients receiving intracavitary radiotherapy, 62% of stage IIB, 49% of stage III and 25% of stage IV patients receiving radiotherapy survived for 5 years. Conclusion: Higher 5-year survival in our study than elsewhere in India is due to the high proportion of early stage cancers detected by screening combined with adequate treatment, resulting into a favourable prognosis.

Prevention of Cervix Cancer in India.

Cervical cancer is the fourth most common cancer among women globally and the second most common cancer among Indian women. India alone bears 23% of the global cervical cancer burden. In India, population-based cervical cancer screening is largely nonexistent in most regions due to competing healthcare priorities, insufficient financial resources and a limited number of trained providers. Hence, most of the cases present in advanced stages of the disease, thus leading to increased mortality and reduced survival. Various screening options like cytology, visual-based screening and testing for high-risk HPV are available. Several cross-sectional studies have looked at the comparative efficacy of different screening tests. Three important randomized controlled trials from India have shown the efficacy of screening once in a life time with HPV DNA, one-time screening with VIA by trained nurses and four-time screening with VIA by trained primary health workers, reducing mortality due to cervical cancers. Prevention of cervical cancers with two-dose HPV vaccination and early detection of precancerous cervical lesions of the eligible population through screening and their appropriate treatment with a single-visit 'screen-and-treat' approach appear to be promising for low-middle-income countries including India.

Immunogenicity and HPV infection after one, two, and three doses of quadrivalent HPV vaccine in girls in India: a multicentre prospective cohort study.

BACKGROUND: An 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. METHODS: Our 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. FINDINGS: Vaccination 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 4·2-5·1). INTERPRETATION: Despite the limitations imposed by the suspension of the HPV vaccination, our findings lend support to the WHO recommendation of two doses, at least 6 months apart, for routine vaccination of young girls. The short-term protection afforded by one dose of HPV vaccine against persistent infection with HPV 16, 18, 6, and 11 is similar to that afforded by two or three doses of vaccine and merits further assessment. FUNDING: Bill & Melinda Gates Foundation.