Analysis Model for Vaccination Programs: HPV Vaccination Rate Estimated

Note: This is an automated translation (using DeepL) of the original German article.

Dexhelpp Partner TU Wien Conducted Study to Analyze Progress of HPV-Immunization in Austria

The World Health Organization (WHO) has set itself the goal of eliminating cervical cancer in 2020. To this end, 90% of all girls worldwide up to the age of 15 are to be vaccinated against human papillomavirus (HPV) by 2030. In order to be able to monitor progress towards this goal, the Federal Ministry of Social Affairs, Health, Care and Consumer Protection (BMGSPK) commissioned Dexhelpp partner TU Wien (Vienna University of Technology) to conduct a model-based analysis of the vaccination rate. The report of this analysis has now been published by the BMGSPK and can be downloaded from their website.

It is estimated that at least 80% of all individuals become infected with HPV during their lifetime. Of the approximately 200 known subtypes, about 14 are oncogenic and represent the major cause of precancerous lesions and cancers of the cervix, vagina, and anus. In addition, HPV is increasingly associated with cancers of the head and neck. Therefore, contrary to earlier assumptions, infection also poses a significant health risk to men.

For this reason, vaccination is recommended in Austria not only for women, but for all persons between the ages of 9 and 30. Up to the age of 21, two vaccination doses are required; older persons need an additional third vaccination. Further information on the disease, epidemiology and significance of HPV, as well as the free vaccination program, can be found in the BMGSPK's "Vaccination Plan Austria".

To calculate the vaccination coverage rate, it was necessary to combine public health data (number of vaccinations purchased and documented under the free vaccination program) and data from a pharmaceutical company (sales figures from the vaccine manufacturer MSD). This sensitive merging was made possible, thanks to years of experience in the transparent but secure handling of sensitive health data within Dexhelpp.

The present results were calculated with data up to the year 2021. It is planned to evaluate current vaccination coverage rates annually in the future, as is already the case in projects calculating MMR and polio vaccination coverage rates.

Among 14-year-olds, about 53% of children will have received both vaccinations by 2021, according to the model. For the first dose, the vaccination coverage rate is 56%. Overall, according to the model, more than 37,000 of the current 14-year-olds (out of approximately 84,000) are still unvaccinated.

Among 14-year-olds, according to the model, around 53% of children will have received both vaccinations by 2021. For the first dose, the vaccination coverage rate is 56%. Overall, according to the model calculation, more than 37,000 of the current 14-year-olds (out of approx. 84,000) are still unvaccinated. In addition, it is noticeable that the vaccination coverage rates in 2020 and 2021 were lower than in the corresponding age group in the years before, especially among 9- and 10-year-olds. Here, it is important to observe whether this is a general decrease in vaccination readiness or whether there was limited access to the free vaccinations due to the pandemic-related school closures. In particular, significantly fewer vaccinations were documented under the free vaccination program in 2020 than in previous years. Care should be taken to ensure that these children catch up on their vaccinations in the coming years and that no vaccination gap opens up. Further results for other age groups can be found in the report of the BMGSPK.

In Austria, vaccination is administered to (and also recommended for) all sexes as part of the free vaccination program. However, there are currently no data available on the gender distribution among the nearly 45,000 14-year-olds who have already been fully vaccinated. There is also no gender-specific information in the sales figures. Therefore, it is currently not possible to evaluate how close Austria is to the WHO target of 90% vaccination coverage among 14-year-old females. Since the calculated vaccination coverage rates are not comparable to countries that report them only for females (and not the total population). As HPV vaccination is still very often mentioned only in connection with cervical cancer, it can be assumed that far more young women than young men are vaccinated, but this cannot be proven on the basis of the data. In this respect, at least a differentiation by gender in the data collection is recommended in the following.

In the current research project, an existing dynamic population model was adapted to calculate the vaccination coverage rate. Thanks to this model, it is possible to incorporate new knowledge into the calculation in the future. For example, information on the sex distribution of vaccination can be taken into account if necessary, or known vaccination coverage rates of other countries can be integrated into the model to better estimate the vaccination status of immigrants. Changes in the framework can also be easily implemented. For example, increasing the age limit of the 2-dose schedule from 15 years to 18 years (in 2022) and then to 21 years (in 2023); or introducing free vaccination until age 21 (starting in February 2023).

Note that this project does not currently make a statement about protection against cervical cancer or any other cancer caused by HPV, so no vaccine efficacy or HPV type coverage is considered. For such a statement, additional information on vaccination protection must still be used and the different HPV types, which are only partially covered by vaccination, must be considered, which is also possible thanks to the model used.

External link to the ministry of health report "Human papillomavirus (HPV) vaccination coverage rates".

Description of the HPV calculation model (in German), published 2023-04-27
Description of the HPV calculation model (in German), published 2023-02-16