Undernutrition impairs measles, tetanus vax responses in children

Children who are undernourished may have a compromised immune response to certain vaccines, and this impaired response can contribute to the burden of vaccine-preventable diseases, according to the VHEMBE* South African birth cohort study.

In an analysis where undernutrition was assessed as stunting and other anthropometric measures, children who were stunted or had any indicator of diminished growth at 3.5 years had a 24.1-percent (95 percent confidence interval [CI], –44.2 to 0.6) or a 27.2-percent (95 percent CI, –45.1 to −1.3) lower antibody titre for measles, respectively, when compared with those who had normal growth. [Vaccine 2024;doi:10.1016/j.vaccine.2024.126564]

Furthermore, a 36.8-percent (95 percent CI, −59.3 to −7.0) lower antibody titre for tetanus was observed in girls with any indicator of diminished growth at 3.5 years relative to those without. This difference was not evident in boys.

No association was seen between undernutrition and Haemophilus influenzae type b (Hib) antibody titres.

“Our data strongly reinforce the limited existing literature showing that child undernutrition can have a negative impact on the efficacy of vaccines by compromising the immune system’s ability to mount effective responses to vaccines and/or by altering the durability of these responses,” the investigators said.

“The extent of the impact can vary depending on many factors including the specific vaccine, the specific nutritional intake of the child, and other health-related factors,” they added.

The VHEMBE cohort included 621 fully vaccinated children with anthropometric measurements at ages 1, 2, and 3.5 years, as well as antibody level measurements at 3.5 and 5 years. At 5 years of age, 90.4 percent of the children were protected against measles, 66.7 percent against tetanus, and 56.1 percent against Hib.

The average age of the children’s mothers at delivery was 26.4 years. More than half of the mothers (55.4 percent) had less than a high school education, 43.6 percent were primiparous, and 11.6 percent were HIV-positive.

Of the children, 12.1 percent were born preterm (<37 weeks gestation), 7.6 percent had a low birth weight (<2,500 g), and 42.1 percent were breastfed for longer than 18 months. A total of 41.9 percent and 39.1 percent of children were living below the food poverty level at 2 and 3.5 years of age, respectively.

WHO data showed that around 148 million children under 5 years worldwide in 2022 are stunted, with the highest numbers in Asia and sub-Saharan Africa. [https://www.who.int/data/gho/data/themes/topics/joint-child-malnutrition-estimates-unicef-who-wb]

The findings of the study suggest that addressing undernutrition in children may help improve vaccine efficacy and reduce the burden of vaccine-preventable diseases, the investigators said. This has important implications, given the concerning global resurgence of measles in 2018, causing widespread outbreaks across the globe, they added. [https://www.who.int/news/item/05-12-2019-more-than-140-000-die-from-measles-as-cases-surge-worldwide]

*Venda Health Examination of Mothers, Babies and the Environment