Harri Hemilä first studied biochemistry and received his PhD (biochemistry) in 1993. Thereafter he studied medicine and receive MD degree (1999), and PhD (epidemiology) in 2006. His major scientific interest has been the effects of vitamin C on the common cold, and on infections in general. He has not done experimental work of his own in this field, yet he has carried out a number of meta-analyses that have estimated the effects of vitamin C from studies published over half a century. He has also analyzed the effects of vitamin E on infections and on total mortality in the ATBC Study data set of 29,133 Finnish male smokers. Most recently he has carried out meta-analyses on the treatment effects of zinc lozenges on the duration of the common cold. Along with research, he is doing clinical work in the GP context. By the year 2022, he has 161 PubMed publications, 80 of which are focused on vitamin C, 28 on vitamin E, and 14 on zinc lozenges.