Assessing the impact of a gender-neutral approach to HPV vaccination on vaccination coverage for nine-year-old girls in Cameroon: a retrospective, cross-sectional study

This retrospective, cross-sectional study demonstrates that Cameroon's 2023 shift to a gender-neutral HPV vaccination strategy, particularly when combined with community dialogues and intensified routine immunization activities, significantly increased vaccination coverage among nine-year-old girls.

The Gist

Imagine the country of Cameroon is trying to protect its young girls from a serious health threat called HPV, which can lead to cervical cancer later in life. To do this, they introduced a "shield" (the vaccine) in 2020. However, for the first couple of years, not many girls were getting this shield. It was like trying to hand out free umbrellas during a storm, but most people were staying inside or didn't know they needed them.

By 2023, the health officials decided to change the game plan. They tried two big new strategies:

1. The "Everyone's Welcome" Rule (Gender-Neutral Approach): Before, the vaccine was mostly talked about as something just for girls. The new rule said, "This vaccine is for everyone, boys and girls alike!" Even though the study focused on girls, treating it as a universal shield helped remove the stigma and made parents feel more comfortable vaccinating their daughters. It's like realizing that if you teach everyone in a house to lock the doors, the whole family feels safer, not just the person who was originally worried about burglars.
2. The "Community Party" Strategy (CDs + PIRIs): Instead of just waiting for people to come to the clinic, officials went out to the neighborhoods. They held Community Dialogues (like town hall meetings to chat and answer questions) and Periodic Intensification events (like pop-up vaccination festivals). This was like a mobile food truck driving into a neighborhood to serve a hot meal, rather than expecting everyone to walk to the restaurant.

What happened?

The researchers looked at data from all 203 health districts (think of these as neighborhoods or counties) to see if these changes worked. The results were like watching a dry sponge suddenly soak up water:

• The Big Jump: Overall, the number of 9-year-old girls getting vaccinated skyrocketed by nearly 40 percentage points in just one year.
• The Power of the Combo: The districts that used both the "Everyone's Welcome" rule and the "Community Party" strategy saw the biggest success. Their vaccination rates jumped by 55.5% compared to districts that did nothing new. It's like having both a map and a guide; you get where you need to go much faster.
• The "Everyone's Welcome" Rule Alone: Even districts that only switched to the gender-neutral approach (without the extra community events) saw a huge improvement, with a 28.7% increase. This proves that simply changing the message to include everyone made a massive difference.

The Bottom Line

This study shows that to get more kids vaccinated, you can't just stand in a clinic and wait. You have to change the story (making it about everyone, not just girls) and meet people where they are (through community events). When Cameroon did both, they turned a slow trickle of vaccinations into a flood, ensuring far more girls are protected against future cancer.

Technical Summary

Technical Summary: Assessing the Impact of Gender-Neutral HPV Vaccination in Cameroon

1. Problem Statement

Cameroon introduced the Human Papillomavirus Vaccine (HPVV) into its routine immunization schedule in October 2020, specifically targeting 9-year-old girls. However, by the end of 2022, vaccination coverage remained critically low. To address this stagnation and improve uptake, the Ministry of Health implemented a strategic shift in 2023. This new approach involved two primary components:

• Gender-Neutral Vaccination (GNV): Expanding the target population to include all children (both boys and girls) rather than just girls.
• Revamped Delivery Strategy: The integration of Community Dialogues (CDs) and Periodic Intensification of Routine Immunization (PIRIs) activities in selected health districts.

The core challenge was to determine whether these programmatic changes, particularly the GNV approach, effectively increased vaccination coverage among the original target demographic (9-year-old girls) amidst a backdrop of low initial uptake.

2. Methodology

The study employed a retrospective, cross-sectional design to evaluate the impact of the 2023 interventions on vaccination coverage during the 2022–2023 period.

• Data Source: Administrative data were extracted from the District Health Information Software 2 (DHIS2) covering all 203 Health Districts (HDs) in Cameroon.
• Target Population: The analysis focused on the estimated population of age-eligible 9-year-old girls.
• Intervention Groups: Health districts were categorized based on their implementation strategies in 2023:
  • GNV Only: 115 districts (56.7%).
  • GNV + CDs + PIRIs: 74 districts (36.5%).
  • Control/Reference: Districts with no GNV and no intensified activities (implied by the regression comparison).
• Statistical Analysis:
  • Descriptive Statistics: Used to characterize the distribution of districts by strategy and rural/urban status (noting that 75.9% of districts were rural).
  • Multiple Linear Regression: Employed to quantify the effect of GNV and the combined strategy (CDs + PIRIs) on HPVV coverage. The model adjusted for confounding variables, specifically the presence of CDs + PIRIs and the urban/rural status of the district.

3. Key Contributions

• Empirical Evidence on GNV: This study provides one of the first rigorous, large-scale evaluations of a gender-neutral HPV vaccination strategy in a low-resource setting, specifically measuring its downstream effect on the coverage of the primary target group (girls).
• Synergistic Effect Analysis: It isolates the impact of the GNV approach from the impact of intensified delivery strategies (CDs + PIRIs), demonstrating that while GNV alone is effective, the combination with community engagement yields superior results.
• National Scale Data: Unlike previous studies limited to pilot sites, this analysis utilizes nationwide data from all 203 health districts, offering a comprehensive view of programmatic performance across diverse rural and urban contexts.

4. Key Results

The study observed a dramatic improvement in vaccination coverage following the 2023 interventions:

• Overall Uptake: There was a 39.2 percentage point increase in HPVV coverage among 9-year-old girls from 2022 to 2023.
• Regression Analysis Findings:
  • Combined Strategy (GNV + CDs + PIRIs): Districts implementing both the gender-neutral approach and intensified delivery activities showed a statistically significant increase in coverage compared to the control group.
    • Beta Coefficient: 55.5%
    • 95% Confidence Interval (CI): 38.7 – 72.3
    • p-value: 0.000
  • GNV Only: Districts implementing GNV without the specific intensified activities also saw a significant increase compared to the control group.
    • Beta Coefficient: 28.7%
    • 95% Confidence Interval (CI): 12.5 – 45.0
    • p-value: 0.001

5. Significance and Implications

The findings underscore that the Gender-Neutral Vaccination (GNV) approach is a highly effective strategy for increasing HPV vaccine coverage among girls in Cameroon. The study suggests that GNV likely reduces stigma, increases community acceptance, and optimizes logistical efficiency by vaccinating a broader cohort.

Furthermore, the results highlight a synergistic effect: while GNV alone drives significant gains, the combination of GNV with community engagement (CDs) and periodic intensification (PIRIs) nearly doubles the impact (55.5% vs. 28.7% increase). This indicates that structural changes in vaccination policy must be supported by robust community mobilization and delivery intensification to maximize public health outcomes. These insights are critical for other low-and-middle-income countries considering similar shifts in HPV vaccination strategies to accelerate progress toward cervical cancer elimination.