In a cross sectional study among a healthy population in the Nanoro HDSS cohort, hemocytometry will be performed in order to define normal values for that population. In addition, hemoglobin levels can be related to the presence of iron deficiency, thalassemia and malaria and be corrected for important confounding factors, such as the family income, family composition, distance to a healthcare center and vaccination status. This study will allow to assess simultaneously the normal range of hemoglobin values, the prevalence of (different causes of) anemia, the prevalence of subclinical malaria parasitemia, as well as the influence of (timepoint of) vaccination on all these issues. It is hypothized that early vaccination with live attenuated vaccines has a protective effect against malaria and other severe infectious diseases and will result in a better nutritional status, a higher hemoglobin level and a higher threshold of subclinical parasitemia. The protective effect of early vaccination with live attenuated vaccines may be due to the long-term modulation of the immune system through epigenetic changes causing a right balance between the pro- and anti-inflammatory responses. Such balance can be determined by ex-vivo stimulation of whole blood by a variety of stimuli, including Mycobacterium tuberculosis and lipopolysaccharide from Escherichia coli, followed by measurement of ex vivo cytokine production. Previous studies among healthy volunteers in the Netherlands have shown that BCG is indeed capable to induce epigenetic changes and influence immune response by influencing various pathways including through genetic variations in mTOR, HK2, PFKP, GLS, and GLUD1/2 (ref).