Short summary

We aim to study the non-specific immunological effects of providing a single dose of oral polio vaccine to seniors aged 50 and above in Guinea-Bissau. Participants will be randomized 1:1 to OPV or placebo (saline). Outcomes are: 1) Induction of innate trained immunity 2) Systemic inflammation 3) Epigenetic modifications of the innate immune cells

Rationale

OPV has been associated with lower mortality in observational studies among children and adults in contexts with no circulating polio virus. These effects of the vaccine have been termed "non-specific effects". Such effects have also been observed for other live attenuated vaccines such as BCG and measles vaccine. In contrast to other live vaccines, OPV's NSEs seem to be stronger for males than for females. In Guinea-Bissau, a cluster-RCT investigating whether OPV could mitigate the impact of COVID-19, OPV reduced the risk of death/hospitalization/consultation with a doctor in males but not in females.

Description of the cohort

Guinean males over the age of 50.

Data and biological material

We collect 10 mL blood at baseline and after 4 weeks of follow-up

Collaborating researchers and departments

Department of Internal Medicine, Radboud University Medical Centre, The Netherlands

• Prof. Dr. Mihai Netea