Vaccine uptake patterns for COVID-19 and cholera among healthcare workers: a cross-sectional study in Yaounde-Cameroon

This cross-sectional study in Yaoundé, Cameroon, reveals low COVID-19 (42.4%) and cholera (4.7%) vaccination coverage among healthcare workers, identifying specific professional roles and districts as key predictors while highlighting the critical need to address knowledge gaps and accessibility barriers to improve immunization programs.

The Gist

Imagine the healthcare system in Yaoundé, Cameroon, as a massive, bustling fortress. Inside these walls, the Healthcare Workers (HCWs) are the brave knights and guardians who protect the kingdom from invisible invaders like viruses and bacteria.

This study is like a "roll call" to check if these guardians have put on their armor (vaccines) to protect themselves and the people they serve. The researchers asked two main questions: "How many knights are wearing their COVID-19 armor?" and "How many are wearing their Cholera armor?"

Here is the story of what they found, told in simple terms:

1. The Armor Check: Who is Protected?

The researchers looked at 406 healthcare workers (mostly nurses and women) across seven different hospitals in the city.

• The COVID-19 Armor: About 42% of the guardians had their full armor on (fully vaccinated). While that's better than nothing, it means more than half (58%) were still walking around without full protection.
• The Cholera Armor: This was the big surprise. Only 4.7% (less than 1 in 20) had their Cholera armor on. It's like having a fortress with a giant hole in the wall where a specific enemy (cholera) could easily sneak in.

2. The Map of Protection

The study showed that protection wasn't spread evenly.

• The Strongholds: The hospitals in Biyem-Assi and Odza were like the best-defended castles, with over half their staff vaccinated against COVID-19.
• The Vulnerable Spots: In the Nkolndongo district, the Cholera protection was the lowest, with only about 11% of staff vaccinated.

3. Who is Most Likely to Wear the Armor?

The researchers tried to figure out why some people wore their armor and others didn't. They found some interesting patterns:

• The "Frontline" Effect: Nurses and Laboratory Technicians were much more likely to be vaccinated against COVID-19.
  • The Analogy: Think of nurses as the soldiers on the front lines, constantly touching the enemy. They know the danger is real, so they are more eager to put on their shields. Lab technicians are like the spies who handle the enemy's weapons (samples) before anyone knows they are dangerous, so they are also very careful.
• The "Cholera" Connection: For Cholera, the people most likely to be vaccinated were those working in Internal Medicine wards and Nurses.
  • The Analogy: Internal Medicine wards are like the "waiting room" for the sickest patients. If you work there, you know you are dealing with the most vulnerable people, so you feel a stronger duty to protect yourself.

4. The Knowledge Gap: Knowing the Rules

Here is the tricky part: Most of the guardians knew they were in a dangerous place.

• 63% of them admitted their workplace was "high risk."
• However, they didn't always know which armor they needed.
  • Almost everyone knew about Hepatitis B and COVID-19 vaccines.
  • But only 18% knew that there was even a vaccine for Cholera!

It's like a soldier knowing the battlefield is dangerous but not knowing that a specific type of shield exists to stop a specific kind of arrow.

5. Why is this happening?

The study suggests a few reasons why the armor isn't on everyone:

• Misinformation: Rumors and false stories about vaccines are spreading like weeds, scaring people away.
• Access: Sometimes the armor is just hard to get or costs too much money.
• Confusion: Many workers simply don't know the rules. They aren't told, "Hey, you need this specific shot."

The Bottom Line

The researchers conclude that while the healthcare workers in Yaoundé are brave, they are currently under-protected.

To fix this, the "Kingdom" (the health authorities) needs to:

1. Educate: Tell the workers clearly which vaccines they need, especially for diseases like Cholera that they might not know about.
2. Make it Easy: Bring the armor directly to them at work so they don't have to go out of their way to get it.
3. Build Trust: Stop the rumors and explain why the armor works, so the guardians feel safe wearing it.

If the guardians are safe, the whole kingdom (the patients and the public) stays safe too. It's a classic case of "protect the protectors."

Technical Summary

1. Problem Statement

Healthcare workers (HCWs) are at a heightened risk of infection due to frequent contact with pathogens and serve as critical vectors for disease transmission to patients and the community. Despite being prioritized for immunization, vaccine hesitancy and low uptake persist in Cameroon, driven by misinformation, fear of adverse effects, and insufficient knowledge. While national efforts have been made to combat COVID-19 and recurrent cholera outbreaks, there is a significant gap in understanding the specific determinants of vaccine acceptance among HCWs in this context. This lack of data hinders the development of targeted strategies to improve epidemic preparedness and occupational safety.

2. Methodology

• Study Design: A hospital-based cross-sectional and analytical study.
• Setting: Seven District Hospitals (DHs) in Yaoundé, the capital of Cameroon (Biyem-Assi, Cité-Verte, Djoungolo-Olembe, Efoulan, Mvog-Ada, Nkolndongo, and Odza).
• Study Period: January to June 2024.
• Participants: 406 HCWs (out of 450 contacted, 90% response rate) from various clinical units including surgery, internal medicine, pediatrics, laboratory, and emergency departments.
• Sampling: All consenting personnel in selected departments were enrolled. The sample size was calculated using the single proportion formula ($n=380$) with a 10% dropout allowance.
• Data Collection: An anonymous, structured, self-administered questionnaire covering socio-demographics, knowledge of vaccines, working environment perception, and vaccination status.
• Definitions:
  • Fully Vaccinated (COVID-19): Completed primary series (1 dose of J&J or $\ge$2 doses of Pfizer/AstraZeneca).
  • Fully Vaccinated (Cholera): Completed at least 2 doses of oral vaccine (Shanchol or Euvichol).
• Statistical Analysis: Data were analyzed using R (v4.3.3). Descriptive statistics were used for demographics. Fisher's exact test compared proportions. Simple and multiple binary logistic regressions identified predictors, with model selection based on the Akaike Information Criterion (AIC). Significance was set at $p < 0.05$.
• Ethics: Approved by the Faculty of Medicine and Biomedical Sciences IRB and the Regional Delegation of Public Health. Informed consent was obtained from all participants.

3. Key Contributions

• Dual-Disease Focus: Unlike many studies focusing solely on COVID-19, this research simultaneously evaluates uptake for both COVID-19 and cholera, two distinct but critical infectious threats in Cameroon.
• Granular Determinant Analysis: It identifies specific professional and demographic predictors (e.g., specific job titles and ward assignments) that influence vaccine acceptance, moving beyond general demographic trends.
• Knowledge Gap Identification: The study highlights a critical disconnect between risk perception (high) and knowledge of specific vaccine recommendations (low), particularly for cholera.

4. Key Results

Demographics

• Composition: 75.6% female; 65.5% aged 30–44 years; 61.3% nurses; 17.0% doctors.
• Education: 78.6% held tertiary education.

Vaccination Coverage

• COVID-19: Only 42.4% were fully vaccinated. Coverage varied by district, with Biyem-Assi (53.0%) and Odza (46.0%) having the highest rates.
• Cholera: Uptake was critically low, with only 4.7% fully vaccinated. Nkolndongo (11.5%) had the highest rate among districts.
• Partial Vaccination: 0.2% for COVID-19 and 15.0% for Cholera.

Predictors of Uptake (Multivariate Analysis)

• COVID-19 Vaccine:
  • Nurses: Significantly more likely to be vaccinated compared to doctors (aOR = 3.96; 95% CI: 2.07–7.81; $p=0.001$).
  • Laboratory Technicians: Highest likelihood of uptake (aOR = 8.00; 95% CI: 1.38–69.8; $p=0.032$).
  • Note: Being female was significant in univariate analysis but not in the final multivariate model.
• Cholera Vaccine:
  • Internal Medicine Ward: Working in this department was a strong predictor (aOR = 11.2; 95% CI: 1.04–120; $p=0.046$).
  • Nurses: Significantly associated with uptake (aOR = 1.54; $p=0.001$).

Knowledge and Perception

• Risk Perception: 62.8% of HCWs perceived their work environment as "high risk" for infection.
• Vaccine Knowledge: While 87.5% knew about Hepatitis B and 61.3% about COVID-19 vaccines, only 18.7% were aware of cholera vaccination recommendations.

5. Significance and Implications

• Occupational Health Policy: The study reveals that current immunization programs for HCWs in Cameroon are insufficient, particularly for cholera. The low uptake (4.7%) despite high perceived risk suggests a failure in communication and access rather than a lack of awareness of the danger.
• Targeted Interventions: The findings suggest that strategies should be tailored by profession and department. For instance, while nurses and lab technicians are more proactive regarding COVID-19, broader education is needed for other cadres. For cholera, specific focus on internal medicine wards and general awareness campaigns are required.
• Systemic Barriers: The disparity between high-risk perception and low vaccination uptake indicates barriers such as limited availability of vaccines, financial constraints, or lack of institutional mandates for non-routine vaccines.
• Future Directions: The authors recommend integrating non-routine vaccines (like cholera) into occupational health programs, ensuring free access within healthcare facilities, and launching behavior change communication campaigns to address the knowledge gap regarding cholera.

In conclusion, this study provides critical evidence that while some HCW groups (nurses, lab techs) are more compliant with COVID-19 vaccination, overall coverage remains suboptimal, and cholera vaccination is virtually non-existent among the workforce. Addressing these gaps is essential for protecting the healthcare workforce and maintaining public trust in vaccination programs.