- pregnant women will be excluded from both cohort 1 and cohort 2. patients with allergies to the investigational products will be excluded cohort 1 (ivermectin) lactating mothers will be excluded cohort 2 (aspirin): - taking aspirin or other non steroidal anti-inflammatory drugs for any reason. - any bleeding disorder (e.g. frequent nose bleeds, haemophilia) - active or recurrent peptic ulcer disease (defined as currently on triple therapy or had more than 1 course of triple therapy in the past 12 months. do not count symptoms of gastritis or on omeprazole as peptic ulcer disease) - current active gastrointestinal haemorrhage - severe liver disease or severe kidney disease (severe liver disease defined as cirrhosis with portal hypertension and history of variceal bleeding; severe kidney disease defined as stage 4/5 kd, egfr <30ml/min) - gout - suspected intra-cerebral haemorrhage - diagnosed with a stroke on this admission

- pregnant women will be excluded from both cohort 1 and cohort 2. patients with allergies to the investigational products will be excluded cohort 1 (ivermectin) lactating mothers will be excluded cohort 2 (aspirin): - taking aspirin or other non steroidal anti-inflammatory drugs for any reason. - any bleeding disorder (e.g. frequent nose bleeds, haemophilia) - active or recurrent peptic ulcer disease (defined as currently on triple therapy or had more than 1 course of triple therapy in the past 12 months. do not count symptoms of gastritis or on omeprazole as peptic ulcer disease) - current active gastrointestinal haemorrhage - severe liver disease or severe kidney disease (severe liver disease defined as cirrhosis with portal hypertension and history of variceal bleeding; severe kidney disease defined as stage 4/5 kd, egfr <30ml/min) - gout - suspected intra-cerebral haemorrhage - diagnosed with a stroke on this admission