When analyzing the data from the early MV trial it became clear that there were strong interactions between early MV and NVAS. Early MV had no effect on overall mortality in children who had click here received NVAS, whereas a strong beneficial effect was seen among children who had not received NVAS, either because they had been randomized to placebo or because they had not participated in the NVAS trials [5].

Though neither NVAS nor early MV is currently recommended, the situation may change. Three new NVAS trials are ongoing [7] and NVAS may become policy if these new trials show a beneficial effect. The early MV trial showed a remarkably strong beneficial effect of early MV in children who had not received NVAS. The trial is currently being repeated in several West African countries

which do not use NVAS. If results are replicable early MV may also become policy. It is therefore important to assess whether there is interaction between NVAS and early MV. In the present paper we analyzed the potential interaction between NVAS and early MV in 5141 children who participated in both an NVAS trial and the early MV trial. We compared the mortality of NVAS and placebo recipients: first, in the time window from 4.5 to 8 months for children randomized to early MV or no early MV, and second, from 9 to 17 months in children who had received two MV or one MV, respectively. The study was a reanalysis of previously conducted randomized trials of NVAS and early MV, respectively. The trials were conducted to study the effect of NVAS and MV, respectively, and the idea to study the potential interactions PD-1/PD-L1 inhibitor 2 between the two interventions only occurred after the completion of the trials. Hence, the size of the present study was not based much on a prespecified hypothesis and corresponding sample size calculations, but defined by the number of children who had participated in both a NVAS trial and the early MV trial. Information on exposure (randomization to NVAS and early MV) and outcome (overall mortality) was available

from the trial databases. The Bandim Health Project (BHP) maintains a demographic surveillance system in six suburban districts of the capital of Guinea-Bissau and covers approximately 102,000 inhabitants. There are three health centers in the study area, one has a maternity ward. The national hospital where many women from the study area give birth is a few kilometers away. BHP assistants are placed at the health centers and the hospital to register all study area children. All houses in the study area are visited monthly to register new pregnancies and births. All children below 3 years of age are followed through home visits every third month. UNICEF classifies Guinea-Bissau as having vitamin A deficiency as a public health problem [8]. The country has implemented VAS campaigns for children between 6 months and 5 years of age.