Summary of the NACI Update on the recommended use of Human Papillomavirus (HPV) vaccine: Nine-valent HPV vaccine two-dose immunization schedule and the use of HPV vaccines in immunocompromised populations
Bibliographic record
Abstract
BACKGROUND: Human papillomavirus (HPV) infections are the most common sexually transmitted infections. In the absence of vaccination, it is estimated that 75% of sexually active Canadians will have an HPV infection at some point in their lives. HPV vaccine programs were first recommended by Canada's National Advisory Committee on Immunization (NACI) in 2007. In addition to the existing HPV vaccine options in Canada, NACI recently recommended the use of a newly authorized nine-valent HPV (HPV9) vaccine according to a 3-dose immunization schedule for the prevention of HPV types 6-, 11-, 16-, 18-, 31-, 33-, 45-, 52- and 58-related cancers and anogenital warts in females aged 9 to 45 years and males aged 9 to 26 years. New data have emerged evaluating a 2-dose immunization schedule for HPV9 vaccine in males and females, which NACI reviewed in order to provide timely guidance on the possibility of a 2-dose immunization schedule for HPV9 vaccine. Recently, a growing number of studies have also specifically explored the responses of immunocompromised subgroups to HPV vaccines, which also triggered a NACI literature review and updated recommendations on this topic. OBJECTIVES: To review evidence for a 2-dose immunization schedule of the HPV9 vaccine and provide recommendations on vaccine schedule; and to summarize evidence from a recent NACI literature review on the use of HPV vaccines in immunocompromised populations and provide recommendations for HPV vaccine use in these groups. METHODS: The NACI HPV Working Group reviewed results from a clinical trial of HPV9 vaccine administered with a 2-dose immunization schedule in males and females (protocol V503-010) and performed a literature review on the topic of HPV immunization of immunocompromised populations. The NACI literature review and the NACI statement were published separately. RESULTS: Only one study investigated a 2-dose immunization schedule with HPV9 vaccine, a large manufacturer-sponsored randomized controlled trial (protocol V503-010) of good quality. Taken in context of studies with other HPV vaccines, NACI considered this study to be a sufficient evidence base for recommendations. Through a comprehensive literature review, 27 studies were identified for evidence synthesis including reports on vaccine immunogenicity, safety, or both for immunocompromised populations. CONCLUSIONS: Based on the evidence reviewed, NACI issued new recommendations for the use of HPV9 vaccine with a 2-dose immunization schedule at 0, 6-12 months in young females and males and updated the grade of evidence for the use of HPV vaccines in immunocompromised populations.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.007 | 0.031 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.003 | 0.003 |
| Bibliometrics | 0.007 | 0.005 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.003 | 0.001 |
| Research integrity | 0.003 | 0.004 |
| Insufficient payload (model declined to judge) | 0.017 | 0.008 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".