Schedule of Evaluations: Study evaluations will be based on three 30 day cycles (Influenza vaccine, Pneumococcus vaccine, Placebo in random order) over 28 weeks of the RCT. Pre injection: one paired blood and genital secretion sample will be collected before each injection. Post-injection: paired blood and genital secretion samples will be collected on days 2, 4, 7, 14 and 30 after each injection.