Children in middle-income countries can face difficulties when accessing WHO-recommended vaccines.

Bridging the vaccine introduction gap in Asia’s middle‑income countries

When it comes to introducing new vaccines, many middle‑income countries across Southeast Asia and South Asia are falling behind – putting progress toward the World Health Organization (WHO) Immunization Agenda 2030 targets at risk – according to a new study led by Duke Kunshan University in partnership with NCIRS Global Health.

The study, published in Vaccine, compared national immunisation programs across 13 countries in Southeast Asia and South Asia to examine why gaps in vaccination introduction persist, and what can be done to close them.

Funding status impacts vaccine introduction progress 

To assess how Gavi funding status influences the introduction of vaccines, the study compared national immunisation programs across Bangladesh, Cambodia, Lao PDR, Myanmar, India, Indonesia, Pakistan, the Philippines, Vietnam, Malaysia, Singapore, Sri Lanka and Thailand.

The analysis revealed clear differences in how quickly countries introduce WHO‑recommended vaccines, depending on funding status.

Middle-income countries navigating the transition from full Gavi funding to self‑financed immunisation programs had:

• fewer vaccine preventable diseases covered in national immunisation programs
• fewer WHO‑recommended vaccines included in national immunisation programs (an average of 8.3 vaccines verses 9.2 for fully funded countries and 9 for countries ineligible for funding).

Delays were most pronounced for newer vaccines.

Pneumococcal conjugate vaccine (PCV), rotavirus vaccine and human papillomavirus (HPV) vaccine have not been introduced in a timely manner across many of the countries in the study.

Among these, rotavirus vaccine lags furthest behind, with only 5 of the 13 countries having included it in their national immunisation programs.

These gaps highlight how funding transitions, pricing, and system readiness continue to shape access to immunisation – often leaving middle-income countries without the full protection offered by newer, life‑saving vaccines.

Why middle‑income countries are being left behind

Middle‑income countries now account for the majority of the world’s zero‑dose children – those who have not received a single routine vaccine.

According to WHO, 69% of zero‑dose children live in middle-income countries, with more than one‑third residing in countries that are not eligible for Gavi support.

As external funding declines, many countries either ineligible for Gavi funding or transitioning from Gavi support face compounding challenges, including unstable domestic vaccine financing and declining immunisation coverage rates.

These pressures are particularly evident for key WHO‑recommended vaccines.

Coverage for PCV, HPV vaccine and rotavirus vaccine in middle-income countries ineligible for Gavi funding remains well below Immunization Agenda 2030 targets, and in many cases, lower than in less‑resourced countries that are still eligible for Gavi funding.

This underscores a critical paradox – countries with growing economic capacity are increasingly at risk of being left behind when it comes to accessing vaccines if they cannot access targeted support to strengthen systems.

Key barriers to introducing new vaccines

The study identified 4 major barriers limiting the introduction of vaccines in middle-income countries ineligible for Gavi funding:

• Underdeveloped decision‑making processes – countries often lacked formal, well‑resourced National Immunisation Technical Advisory Groups (NITAGs), slowing evidence‑based decisions.
• Limited domestic financing – transitioning away from donor support left many countries struggling to sustain or expand vaccine programs.
• High vaccine prices – without pooled procurement or donor‑negotiated pricing, middle-income countries frequently faced higher per‑dose costs.
• Immunisation system readiness gaps – issues such as cold‑chain capacity, workforce constraints and inadequate delivery infrastructure delayed roll‑out even after policy approval.

Implications for equitable access and regional health security

Delays in introducing life‑saving vaccines have consequences beyond national borders.

Gaps in population immunity increase the risk of outbreaks of vaccine preventable diseases, threatening both equitable health outcomes and regional health security.

The study emphasises that without targeted action, middle-income countries caught between donor support and full self‑financing may continue to lag – despite having growing disease burdens and expanding adolescent and adult vaccination needs.

Options for action

To accelerate progress, the study calls for:

• stronger governance and decision‑making, including investment in NITAG capacity
• sustainable domestic financing strategies for immunisation
• optimised resource use to improve system performance
• targeted technical support from global and regional partners.

Closing gaps in vaccination introduction is essential to ensure that all countries – regardless of income status – can introduce and sustain access to new vaccines and move closer to Immunization Agenda 2030 goals.

Read the full study