Breaking the vicious cycle of malnutrition and infectious disease

In the fight to reduce child morbidity and mortality worldwide, we face two major issues: malnutrition and infectious diseases. What makes things all the more challenging is that the two are interconnected. Multiple deprivations, including lack of access to health services, not being vaccinated, poverty and gender-related barriers, can all intertwine to leave children vulnerable.

It stands to reason that if malnutrition prevents the activation of a strong immune response to infection, it could also reduce the effectiveness of immunisation

The World Health Organization estimates that globally 149 million children under five are ‘stunted’, meaning they are too short for their age. Forty-five million are too thin for their height, a condition called wasting. Both stunting and wasting are manifestations of undernutrition. Around 45% of all deaths under the age of five — most of which occur in low- and middle-income countries – are linked to undernutrition.

Meanwhile, food insecurity means that increasingly families don’t have consistent access to enough of the right kinds of food. Struggling to give children the nutrients they need to grow stronger and healthier, families face another related problem: infectious disease. This is because immune responses to infections are compromised in malnourished individuals.

This is especially worrisome because an alarming number of malnourished children are often the very same ones in need of vaccines for diseases from which they have a high risk of dying. These include diarrhoea, measles, meningitis, tuberculosis, influenza and bacterial pneumonia.

It stands to reason that if malnutrition prevents the activation of a strong immune response to infection, it could also reduce the effectiveness of immunisation. It is a vicious cycle and we’ve known about it for more than 50 years.

As we put efforts into ensuring food security, it is imperative that we:

1. Scale up efforts to combine interventions tackling the nexus of malnutrition and infectious diseases; and
2. Study the effects of the interventions to improve them.

Breaking the cycle: how better nutrition and vaccination can help

If we address this self-perpetuating cycle, we need to vaccinate more children, while at the same time improving their diet through nutritional advice and supplements.

Immunisation-nutrition integration (INI) is a strategic approach that combines nutrition and immunisation interventions to improve child health and well-being. The best window of opportunity for INI opens before a child is even conceived, and lasts until the age of five.

Parents who have been vaccinated against HPV and other viruses, and who also have a diet supplemented with micronutrients, are healthier – which in turn increases the odds of healthier babies. For example, maternal vaccination against influenza has been shown to reduce low birth weight by 15%.

Following birth, breastfeeding provides milk that is rich in nutrients and antibodies. This helps to nourish children, protect them from infection while their own immune systems are maturing, and even improve their responses to vaccines.

Reciprocally, immunisation keeps infectious diseases at bay, and means they are better protected against malnutrition. At the same time, providing nutritional supplements at vaccination can both combat malnutrition and boost a child’s response to vaccines. Studies have shown that vitamin A and iron do this for polio and measles vaccines. In other words, it’s a virtuous cycle.

INI could be especially helpful in reaching zero-dose children, who are more likely to be malnourished and to live in families facing multiple deprivations. One study, which included data from 80 countries, found that stunted children are 32% more likely to be zero-dose than to have received at least one vaccine.

Integrating nutrition and immunisation services can help to improve the impact and success of both interventions. For example, children may be more likely to receive immunisations if they are also receiving nutrition services at the same time. This is of particular importance for populations in a humanitarian crisis, where there is high risk of malnutrition alongside disruption to health services.

Building resilience through partnership amid global shocks

Gavi is already invested in partnerships that use integrated programmes to improve vaccination status and health outcomes. For example, in Indonesia, Gavi is working with Unilever Lifebuoy and The Power of Nutrition to improve hygiene, nutrition and immunisation, evidencing that powerful partnerships and multi-sector investments have a role to play in generating demand for health seeking behaviours.

Another example is Ethiopia, where the Seqota declaration is aiming to end all forms of malnutrition in the country by 2030. The Children’s Investment Fund Foundation (CIFF) has recently allocated US $15 million to UNICEF Ethiopia’s “End Child Wasting” programme and Gavi is matching the investment backed by the UK Foreign, Commonwealth and Development Office’s (FCDO) Matching Fund.

The programme will support Vitamin A supplementation, screening and immunisation. It will also support UNICEF’s work in distributing therapeutic food for treating severe acute malnutrition in the drought-prone regions of Ethiopia.

In Nigeria, the Eleanor Crook Foundation has partnered with Gavi for an implementation research project, Nutrivax, to better understand the impact of delivering nutrition services and vaccines together.

But more can be done.

That is why this year at the global food security summit hosted by the Foreign Commonwealth d Development Office (FCDO) – along with the Bill & Melinda Gates Foundation and the CIFF – Gavi is proposing that INI efforts through health systems strengthening initiatives should be scaled up.

Such an effort would help us understand the cost-effectiveness and efficiency of the programmes. This would enable us to replicate success strategies in tackling malnutrition and infectious disease. Collaboration must underpin this effort, as it is only together that we can protect the most vulnerable children and their families, whose resilience is constantly tested.

Multiple global shocks, including the COVID-19 pandemic, conflict in Ukraine and the Middle East and climate-related disasters are exacerbating the food supply crisis and worsening malnutrition. A better understanding of the dual impact of INI programmes on both nutrition and immunisation status can help us reach more children, especially zero-dose children, and improve their overall health and well-being. This, in turn, can reduce vulnerability for both these children and their communities.