Human Papillomavirus (HPV) vaccination coverage among French adolescents: A claims data study.

BACKGROUND: The French cancer control strategy 2021-2030 aims to achieve 80 % human papillomavirus (HPV) vaccination coverage. Since 2021, HPV vaccination is also recommended for boys aged 11-14 years, with a catch-up vaccination recommended for unvaccinated adolescents aged ≤19 years. The PAPILLON study used claims data to monitor the evolution of HPV Vaccination Coverage Rate (VCR) in the French population. METHODS: The annual HPV VCR was described from 2017 to 2022. Partial vaccination was defined as the dispensing of at least one dose of HPV vaccination. Full scheme vaccination was defined according to the current French recommendations as two or three doses of HPV vaccine over an 18-month period. Annual HPV vaccine initiation rates were estimated on 11-14 and 15-19-year-olds adolescents. Cumulative VCR were estimated on adolescents aged between 11 and 19 years at the time of first vaccination. RESULTS: Overall, 1,773,900 females and 592,167 males initiated HPV vaccination between 2017 and 2022. Initiations occurred between 11 and 14 years for 67.3 % of females and 62.4 % of males with a median time between the first two doses of 195 days and 190 days, respectively. In girls, the cumulative vaccination rate for the partial scheme vaccination at 15 y.o. increased from 28.1 % in 2017 to 50.9 % in 2022. Similarly, the cumulative vaccination rate for the full scheme vaccination at 16 y.o. increased from 15.5 % in 2017 to 33.8 % in 2022. In 2022, the initiation rates for males were 12.6 % at age 14 and 1.9 % at age 19. CONCLUSIONS: HPV vaccination coverage increased between 2017 and 2022 among girls targeted by the recommendation but remains insufficient. The results of this study show a tentative but promising start to vaccination in boys. This study will monitor the effects of actions taken to improve vaccination, including the extension of vaccination competencies to community pharmacists since end of 2022.

The mRNA Vaccination Rate Is Negatively and the Proportion of Elderly Individuals Is Positively Associated With the Excess Mortality Rate After 2020 in Japan.

BACKGROUND: The impact of mRNA vaccines on excess mortality during the COVID-19 pandemic in Japan is not clear. This study aimed to verify the explanatory factors of excess mortality rate using officially published data by government and research institutions. METHODS: Multiple regression analysis was performed using the excess mortality rate in Japanese prefectures as the objective variable and the mRNA vaccination rate, proportion of elderly individuals in the population, number of physicians per population, and medical expenditure per person as explanatory variables. RESULTS: From July 2021 to April 2023, the independent determinants of the excess mortality rate were as follows: proportion of elderly individuals (regression coefficient (B) = 0.0097, p < 0.001), partial vaccination rate (B = -0.0034, p = 0.048), proportion of elderly individuals (B = 0.010, p < 0.001), and third-shot vaccination rate (B = -0.0025, p < 0.046). The stepwise method did not essentially change the results. However, the p-values were smaller. The other two indicators were not associated with the excess mortality rate. CONCLUSIONS: mRNA vaccination was associated with a lower excess mortality in Japan during the period, whereas the proportion of elderly individuals was associated with an increase in excess mortality. Thus, a policy of aggressive recommendations for mRNA vaccination is justified.

Protection Efficacy of the Infectious Laryngotracheitis (ILT) Serva CEO Vaccine Strain in Broiler Chickens Under Different Vaccination Coverage Conditions.

Mass vaccination against infectious laryngotracheitis virus (ILTV) in drinking water can result in variable initial vaccine take. Partial initial vaccine coverage of 20% with an Australian ILT vaccine (A20) previously resulted in significant protection against virulent ILTV challenge. This follow-up study used the international Serva ILT vaccine strain in a factorial design testing four levels of vaccination coverage (0%, 10%, 20%, or 100% of chicks eye-drop vaccinated with the live vaccine at 7 days of age) and three levels of ILTV challenge (no challenge or challenge at 7 or 21 days postvaccination [DPV]). The increase in ILTV load in choanal cleft swabs detected by qPCR after challenge was significantly reduced by 20% and 100% but not by 10% vaccination coverage. Vaccination reduced weight gain in unchallenged birds. Daily weight gain of birds was not affected by ILTV challenge at 7 DPV in any group, but following challenge at 21 DPV, it was significantly reduced in unvaccinated and 10% vaccinated groups relative to 20% and 100% vaccinated groups. Vaccination of 20% of the chickens provided substantial but incomplete protection (protective index range 44%-70%) against the severity of clinical signs and mortality following challenge while 10% vaccination coverage provided limited or no protection. Clinical signs were more severe and appeared earlier following challenge at 21 DPV than at 7 DPV. Within the vaccination treatments, eye-drop-vaccinated birds were better protected than their in-contact cohorts. In conclusion, partial vaccination of 20%, but not 10% of chickens, induced substantial protection against subsequent challenge. However, the attendant risks of reduced protection against early challenge and the possible reversion to virulence of vaccine virus when transmitted to unvaccinated chickens make it essential that 100% initial vaccine take be the goal of mass vaccination programs.

Eficacia protectora de la cepa vacunal CEO Serva del virus de la laringotraqueítis infecciosa (ILT) en pollos de engorde bajo diferentes condiciones de cobertura vacunal. La vacunación masiva contra el virus de la laringotraqueítis infecciosa (ILTV) en el agua de bebida puede resultar en una cobertura vacunal inicial variable. La cobertura vacunal inicial parcial del 20 % con una vacuna ILT australiana (A20) previamente resultó en una protección significativa contra el desafío virulento con el virus de la laringotraqueítis. Este estudio de seguimiento utilizó la cepa de la vacuna vacunal internacional Serva ILT en un diseño factorial para probar cuatro niveles de cobertura de vacunación (0 %, 10 %, 20 % o 100 % de pollitos vacunados por gota ocular con la vacuna viva a los siete días de edad) y tres niveles de desafío con el virus de la laringotraqueítis (sin desafío o con desafío a los 7 o 21 días después de la vacunación [DPV]). El aumento en la carga viral en hisopos de la hendidura coanal detectados por qPCR después del desafío se redujo significativamente con cobertura de vacunación del 20% y 100%, pero no con el 10%. La vacunación redujo el aumento de peso en las aves no desafiadas. La ganancia diaria de peso de las aves no se vio afectada por el desafío con el virus de la laringotraqueítis a los siete días después de la vacunación en ningún grupo, pero después del desafío a los 21 días después de la vacunación, se redujo significativamente en los grupos no vacunados y con cobertura del 10% en comparación con los grupos con cobertura del 20% y 100%. La vacunación del 20 % de los pollos brindó una protección sustancial pero incompleta (con un rango de índice de protección del 44 % al 70 %) contra la severidad de los signos clínicos y la mortalidad después del desafío, mientras que la cobertura de vacunación del 10 % brindó protección limitada o nula. Los signos clínicos fueron más graves y aparecieron más temprano después del desafío a los 21 días después de la vacunación en comparación con el desafío a los siete días después de la vacunación. Dentro de los tratamientos de vacunación, las aves vacunadas con gota ocular estaban mejor protegidas que sus cohortes en contacto. En conclusión, la cobertura de vacunación parcial del 20%, pero no del 10% de los pollos, indujo una protección sustancial contra el desafío posterior. Sin embargo, los riesgos concomitantes de una protección reducida contra el desafío temprano y la posible reversión a la virulencia del virus vacunal cuando se transmite a pollos no vacunados hacen que sea esencial que la cobertura vacunal inicial del 100% sea el objetivo de los programas de vacunación masiva.

Simulating partial vaccine protection: BCG in badgers.

In wildlife disease management there are few diseases for which vaccination is a viable option. The human vaccine BCG has been used for the control of bovine tuberculosis in badgers since 2010 and is expected to increase. Understanding the long-term effects of repeated vaccination campaigns on disease prevalence is vital, but modelling thus far has generally assumed that a vaccine provides perfect protection to a proportion of the population, and that animals exposed to a repeated vaccination have a second independent chance of becoming protected. We held a workshop with experts in the field to obtain consensus over the main pathways for partial protection in the badger, and then simulated these using an established model. The available data supported the possibility that some individuals receive no benefit from the BCG vaccine, others may result in a delayed disease progression and in the remaining animals, vaccine protected the individual from any onward transmission. Simulating these pathways using different levels of overall efficacy demonstrated that partial protection leads to a reduced effect of vaccination, but in all of the identified scenarios it was still possible to eradicate disease in an isolated population with no disease introduction. We also identify those potential vaccination failures that require further investigation to determine which of our proposed pathways is the more likely.

Human papillomavirus (HPV) vaccine coverage rates (VCRs) in France: A French claims data study.

BACKGROUND: The French Cancer Plan 2014-2019 had a target of 60% HPV vaccine coverage. The PAPILLON study investigated the annual age-specific vaccination initiation rates and cumulative partial and complete vaccination rates in France from 2017 to 2022. It also identified the factors associated with vaccination in different age groups and those associated with the type of completion of the vaccination scheme (partial vs full vaccination). METHODS: For this publication, all females recorded in the French National Claims database who initiated HPV vaccination between 1 July 2007 and 31 December 2018 and were aged between 11 and 19 years at initiation were included. Annual HPV vaccination initiation rates were estimated in 11- to 14-year-old (target population) and 15- to 19-year-old females (catch-up). Cumulative vaccine coverage rates (VCRs) were estimated among those who were 15, 16, 20 and 21 years old. Partial vaccination was defined by dispensing of at least one dose of HPV vaccine by the pharmacy, while full vaccination was defined by two or three doses dispensed by a pharmacy over an 18-month period, according to current French recommendations based on the age at vaccination initiation. RESULTS: Among the 465,629 females who initiated HPV vaccination in 2017 or 2018, the initiation rate increased from 7.7 to 11.1% in 11- to 14-year-old girls and from 4.5 to 6.5% in 15- to 19-year-old females. In 2017 and 2018, the cumulative VCRs for partial vaccination by age 15 were 28.2% and 32.8%, respectively, while by age 20, they were 41.6% and 38.8%. The cumulative VCRs for full vaccination were 15.6% and 18.6% by age 16, while they were 25.9 and 23.6% by age 20. HPV vaccination initiation and completion were strongly associated with the use of health services. CONCLUSION: Overall, the HPV VCR substantively increased between 2017 and 2018, which is positive evidence of the resumption of vaccination. Updates in 2022 should confirm these results.

Differential determinants and reasons for the non- and partial vaccination of children among Nigerian caregivers.

BACKGROUND: Vaccination has saved millions of lives. However, the vaccination rate in Nigeria remains low. We differentiate reasons for incomplete vaccination by status: not- and partially- vaccinated, and examine the association between sociodemographic characteristics of caregivers and reasons for incomplete vaccination. METHODS: Data from the Multiple Indicator Cluster Survey (MICS) conducted in Nigeria in 2016 and 2017 was analyzed. The logistic regression was used to evaluate associations between sociodemographic characteristics of caregivers and incomplete vaccination according to different reasons. RESULTS: The most common reason for non-vaccination is that caregivers have no faith in immunization (27.0%), followed by lack of awareness of the need for immunization (26.0%) and the perception that the place where immunization is given is too far/inconvenient (24.3%). The most common reason for partial vaccination is that caregivers thought the children had already been fully immunized (44.8%), followed by the inconvenient location for immunization (15.3%) and supply-side issues such as shortage of vaccine stock and absence of vaccinators (14.4%). Among caregivers whose children are never vaccinated, a lower level of education is correlated with more likelihood of having no faith in immunization and poorer households are more likely to state a lack of awareness of the need for immunization need and an inconvenient place as the reasons for non-vaccination. Among caregivers whose children are only partially vaccinated, educated and wealthier caregivers are more likely to state that they thought their children were fully vaccinated, while poorer caregivers tend to give an inconvenient immunization place as the reason for incomplete vaccination. Supply-side barriers are not systematically correlated with educational attainment or wealth level of caregivers. CONCLUSION: Barriers to vaccination are different according to vaccination status: not- and partially- vaccinated, as is the association between sociodemographic characteristics of caregivers and reasons for incomplete vaccination. The policy to increase vaccination take-up should take these differentials into consideration.