Can a single dose of human papillomavirus (HPV) vaccine prevent cervical cancer? Early findings from an Indian study.
Vaccine
; 36(32 Pt A): 4783-4791, 2018 08 06.
Article
em En
| MEDLINE
| ID: mdl-29551226
ABSTRACT
BACKGROUND:
Human papillomavirus (HPV) vaccination is a major strategy for preventing cervical and other ano-genital cancers. Worldwide HPV vaccination introduction and coverage will be facilitated if a single dose of vaccine is as effective as two or three doses or demonstrates significant protective effect compared to 'no vaccination'.METHODS:
In a multi-centre cluster randomized trial of two vs three doses of quadrivalent HPV vaccination (Gardasil™) in India, suspension of the vaccination due to events unrelated to the study led to per protocol and partial vaccination of unmarried 10-18â¯year old girls leading to four study groups, two by design and two by default. They were followed up for the primary outcomes of immunogenicity in terms of L1 genotype-specific binding antibody titres, neutralising antibody titres, and antibody avidity for the vaccine-targeted HPV types and HPV infections. Analysis was per actual number of vaccine doses received. This study is registered with ISRCTN, number ISRCTN98283094; and with ClinicalTrials.gov, number NCT00923702.FINDINGS:
Of the 17,729 vaccinated girls, 4348 (25%) received three doses on days 1, 60, 180 or later, 4979 (28%) received two doses on days 1 and 180 or later, 3452 (19%) received two doses on days 1 and 60, and 4950 (28%) received one dose. One dose recipients demonstrated a robust and sustained immune response against HPV 16 and 18, albeit inferior to that of 3- or 2-doses and the antibody levels were stable over a 4â¯year period. The frequencies of cumulative incident and persistent HPV 16 and 18 infections up to 7â¯years of follow-up were similar and uniformly low in all the vaccinated study groups; the frequency of HPV 16 and 18 infections were significantly higher in unvaccinated age-matched control women than among vaccine recipients. The frequency of vaccine non-targeted HPV types was similar in the vaccinated groups but higher in the unvaccinated control women.CONCLUSION:
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 7â¯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'.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neoplasias do Colo do Útero
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Infecções por Papillomavirus
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Papillomavirus Humano 16
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Papillomavirus Humano 18
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Vacina Quadrivalente Recombinante contra HPV tipos 6, 11, 16, 18
Tipo de estudo:
Clinical_trials
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Diagnostic_studies
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Guideline
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Observational_studies
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Prognostic_studies
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Risk_factors_studies
Limite:
Adolescent
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Adult
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Child
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Female
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Humans
País/Região como assunto:
Asia
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article