Charlotte Sarfas Poster 2023

Mrs Charlotte Sarfas

UK Health Security Agency, UK

Characterisation of the infant immune system and the influence and immunogenicity of BCG vaccination in infant and adult rhesus macaques

Poster Abstract

In countries where tuberculosis (TB) is endemic, the BCG vaccination is recommended close after birth to protect infants from severe forms of TB. However, BCG has variable efficacy and is not as effective against adult pulmonary TB.

Most animal models used to study novel TB vaccine candidates rely on the use of adult animals. Human studies show that the infant immune system is different to that of an adult. Understanding how the phenotypic profile and functional ability of the immature host immune system compares to that of an adult, together with the immune response induced by BCG, is critical to ensuring that new TB vaccines are tested in the most appropriate models.

The frequency and functionality of cells collected from rhesus macaques vaccinated with BCG near birth, following stimulation with mycobacterial antigens were compared with those collected from unvaccinated age-matched controls over the first three years of life. These immune profiles defined in neonatally immunised individuals were then compared with those determined in similarly treated macaques that received BCG as an adult.

BCG induced an antigen-specific immune response in the peripheral immune compartment when delivered to neonatal and adult macaques. There were differences in the magnitude and type of response induced between the age groups. Pro-inflammatory markers measured in vaccinated neonates were significantly lower, than those in macaques vaccinated as adults. Differences were also apparent in cytokine secretion profiles between the age groups. There were also significant differences in the frequency of cell populations in macaques vaccinated in infancy compared to vaccination later in life.

The age at which BCG vaccination is received impacts the subsequent host immune response to the vaccine and which may influence the protective efficacy afforded.

Biography

I currently work as a project team leader in the non-human primate vaccine evaluation group in tuberculosis research at UK Health Security Agency, Porton. I assist in the evaluation of the immune response after vaccination, therapeutics and also after TB infection. In recent years I have also assisted in the evaluation of SARS- CoV2 vaccines. Alongside my role at UKHSA, i am also undertaking my PhD part-time with the open university, characterising the infant immune system of infant rhesus macaques and investigating the influence and immunogenicity of BCG vaccination in infant and adult rhesus macaques.