Thank you for your question regarding the correct population percentage proportion to use for children aged 0-5 years in developing countries, specifically in the context of the Expanded Programme on Immunization (EPI) and according to the World Health Organization (WHO) standards.

The WHO provides guidelines and standards for various health metrics, including population distributions and immunization coverage. However, the specific percentage proportion of the population aged 0-5 years can vary significantly across different developing countries due to factors such as birth rates, mortality rates, and overall population structure.

For EPI purposes, the WHO often uses demographic and health survey data to estimate the target population for immunization programs. The proportion of the population aged 0-5 years is critical for planning and evaluating immunization coverage. However, there isn't a single percentage that applies universally to all developing countries due to the reasons mentioned above.

To get the most accurate and up-to-date percentage for a specific country or region, it is recommended to consult the latest demographic health surveys, national statistics, or WHO country profiles. These sources can provide the current population structure, from which you can calculate the proportion of children aged 0-5 years.

If you are looking for a general guideline or an estimate for planning purposes, it might be helpful to look into the WHO's "World Health Statistics" reports or the UN's population division data, which provide detailed demographic breakdowns by age group for countries worldwide.

For the most precise and applicable data for your needs, especially if it's for a specific developing country, I recommend directly consulting the relevant WHO regional office or the country's ministry of health. They can provide the most accurate and recent data tailored to your specific context.

I hope this provides clarity and assists you in your inquiry. If you have any further questions or need more specific data, please don't hesitate to reach out.

Best regards,

Hailu Wondim

Hi Joseph

I want to believe there is a standard. For every country you should be able to get these proportions from Demographic surveys or population census. This is because population demographics are not uniform in every country. The number of times the antigen is given will help you in quantification of immunization antigens and commodities