Persistence of Immunity When Using Different Human Papillomavirus Vaccination Schedules and Booster-Dose Effects 5 Years After Primary Vaccination

Usos conceptuales del género y la vulnerabilidad en políticas públicas de atención al Virus del Papiloma Humano (VPH) y al Cáncer Cervicouterino (CaCu) en México

RESUMO El Virus del Papiloma Humano (VPH) es un padecimiento de alto impacto a nivel global: más del 80% de las personas con vida sexual activa lo adquirirá en algún momento. La prevalencia y estragos es mayor en mujeres, pues este virus puede derivar en Cáncer Cervicouterino (CaCu). Desde hace tres décadas, ante el llamado de atención de muchas feministas, organismos de salud internacionales y gobiernos de muchos países han incorporado la perspectiva de género en la atención de estos y otros padecimientos de la salud sexual donde se ha destacado la noción de vulnerabilidad. El objetivo de este artículo es analizar, desde una perspectiva feminista, cuáles son los usos conceptuales que se hacen de la dupla género-vulnerabilidad en algunos documentos de políticas públicas para la atención del VPH y el CaCu de la Organización Mundial de la Salud, la Organización Panamericana de la Salud y la Secretaría de Salud mexicana. A través de un análisis textual de estos documentos, es señalado que el uso conceptual de la vulnerabilidad a la que están expuestas las mujeres por mandatos de género requiere ser vislumbrado desde ópticas que permita reconocer su agencia. Asimismo, se destaca la relevancia de incorporar a los varones a las políticas públicas de atención a estos padecimientos.

Reduction of HPV16/18 prevalence in young women after eight years of three- and two-dose vaccination schemes

BACKGROUND

Recommendations for human papillomavirus vaccination have relied on immunogenicity studies and efficacy results derived from adult women. Insufficient information exists regarding HPV effectiveness in vaccinated girls as they become sexually active, regardless of dose scheme. We aimed to compare the prevalence of high-risk HPV between unvaccinated and vaccinated young women eight years after immunization.

METHODS

After eight years, we recontacted women who received two-dose of bivalent or three-dose-either bivalent or quadrivalent-, HPV vaccine when aged 9-10 years-old as part of a clinical trial. Additionally, we recruited a contemporaneous unvaccinated woman group for comparison. Only those sexually active were included. High-risk HPV DNA was determined in urine samples and compared across groups.

RESULTS

The prevalence of HPV16/18 types was 6.8% (95 %CI 3.2-14.1%) in the unvaccinated (n = 6/88), 1.1% (95 %CI 0.2-5.8%) in the three-dose (n = 1/93), and 0.0% (95 %CI 0.0-7.0%) in the two-dose group (n = 0/51).

CONCLUSION

HPV vaccination, with two-dose of bivalent or three-dose schemes-either with the bivalent or quadrivalent vaccine-, was associated with a lower prevalence of HPV16/18 types eight years after primary immunization.

Immunogenicity of Alternative Dosing Schedules for HPV Vaccines among Adolescent Girls and Young Women: A Systematic Review and Meta-Analysis

Alternative dosing schedules for licensed human papilloma virus (HPV) vaccines, particularly single dose and extended intervals between doses (>12 months), are being considered to address vaccine shortages and improve operational flexibility. We searched PUBMED/MEDLINE for publications reporting immunogenicity data following administration of one of the licensed HPV vaccines (2vHPV, 4vHPV, and 9vHPV) to females aged 9-26 years. We conducted non-inferiority analyses comparing alternative to standard schedules using mixed effects meta-regression controlling for baseline HPV status and disaggregated by vaccine, subtype, time point, and age group (9-14 and 15-26 years). Non-inferiority was defined as the lower bound of the 95% confidence interval (CI) for the geometric mean titer (GMT) ratio being greater than 0.5. Our search returned 2464 studies, of which 23 were included in data analyses. When evaluated against standard schedules, although robust immunogenicity was demonstrated across all multi-dose groups, non-inferiority of extended interval dosing was mixed across vaccines, subtypes, and time points. Single dose did not meet the criteria for non-inferiority in any comparisons. Sparse data limited the number of possible comparisons, and further research is warranted.

Human papillomavirus vaccination 2020 guideline update: American Cancer Society guideline adaptation

The American Cancer Society (ACS) presents an adaptation of the current Advisory Committee on Immunization Practices recommendations for human papillomavirus (HPV) vaccination. The ACS recommends routine HPV vaccination between ages 9 and 12 years to achieve higher on-time vaccination rates, which will lead to increased numbers of cancers prevented. Health care providers are encouraged to start offering the HPV vaccine series at age 9 or 10 years. Catch-up HPV vaccination is recommended for all persons through age 26 years who are not adequately vaccinated. Providers should inform individuals aged 22 to 26 years who have not been previously vaccinated or who have not completed the series that vaccination at older ages is less effective in lowering cancer risk. Catch-up HPV vaccination is not recommended for adults aged older than 26 years. The ACS does not endorse the 2019 Advisory Committee on Immunization Practices recommendation for shared clinical decision making for some adults aged 27 through 45 years who are not adequately vaccinated because of the low effectiveness and low cancer prevention potential of vaccination in this age group, the burden of decision making on patients and clinicians, and the lack of sufficient guidance on the selection of individuals who might benefit.

Assessing an intervention to increase knowledge related to cervical cancer and the HPV vaccine

Human papillomavirus (HPV) infection is the primary risk factor for cervical cancer. While the HPV vaccine significantly reduces the risk of HPV infection and subsequent cervical cancer diagnosis, underuse is linked to lack of knowledge of its effectiveness in preventing cervical cancer. The purpose of this study was to evaluate a cancer educational intervention (titled "MOVENUP") to improve knowledge of cervical cancer, HPV, and the HPV vaccine among predominantly African American communities in South Carolina. The MOVENUP cancer educational intervention was conducted among participants residing in nine South Carolina counties who were recruited by community partners. The 4.5-h MOVENUP cancer educational intervention included a 30-min module on cervical cancer, HPV, and HPV vaccination. A six-item investigator-developed instrument was used to evaluate pre- and post-intervention changes in knowledge related to these content areas. Ninety-three percent of the 276 participants were African American. Most participants reporting age and gender were 50+ years (73%) and female (91%). Nearly half of participants (46%) reported an annual household income <$40,000 and 49% had not graduated from college. Statistically significant changes were observed at post-test for four of six items on the knowledge scale (P<0.05), as compared to pre-test scores. For the two items on the scale in which statistically significant changes were not observed, this was due primarily due to a baseline ceiling effect.

Impact of quadrivalent HPV vaccine dose spacing on immunologic response in women living with HIV

HPV vaccination schedules have changed as evidence has supported reduced dosing and extended intervals. Women living with HIV (WLWH) represent an important population with no data on alternative dosing. Girls and WLWH received quadrivalent HPV (qHPV) vaccine in a pan-Canadian study of immunogenicity and efficacy. Serology was performed at months 0/2/7/12/18/24. Medical and sexual history was collected throughout. Linear regression was used to determine if spacing of doses was associated with peak antibody titer. Multivariable analyses demonstrated significant relationships between peak antibody titer and time to blood draw post last vaccine dose, naivety to the relevant HPV type, and HIV viral load for all qHPV types. There was a significant relationship between peak HPV16/18 antibody titer and age. Taking age, time to serology, CD4 cell count, CD4 nadir, HIV viral load, and HPV naivety into account, spacing of the three qHPV vaccine doses did not significantly impact peak antibody titers.