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John Clemens

Adjunct Professor


DepartmentsType of Faculty
EpidemiologyPart Time
Contact Information
Areas of Interest: 

Professor Clemens’ areas of interest focus on studies and methods to evaluate vaccines in developing countries.

Professor Clemens is an infectious disease epidemiologist with over 30 years of experience designing, conducting, and analyzing large, population-based epidemiologic studies and vaccine field trials in developing countries. A graduate of Stanford (B.S.) and Yale (M.D.) Universities, Professor Clemens trained in Internal Medicine at Case Western Reserve, and received his post-doctoral research training in clinical epidemiology at Yale. From 1983-88, he served as a research scientist at the International Centre for Diarrhoeal Disease Research, Bangladesh, where he led the first efficacy trial of an oral vaccine against cholera. After returning to the U.S., he served as Chief of the Epidemiology Section of the Center for Vaccine Development of the University of Maryland, and then as Chief of the Epidemiology Branch of the National Institute of Child Health and Human Development , U.S. National Institutes of Health (NIH). While at NIH he was the Director of the first WHO Collaborating Centre for Vaccine Evaluation in Developing Countries. In 1999 he became the first Director-General of the International Vaccine Institute (IVI). While at IVI he led the team that developed a killed oral cholera vaccine that achieved licensure in India in 2009 and WHO prequalification in 2010. In 2011 he moved to UCLA, where he continues to serve as Adjunct Professor of Epidemiology. From 2013-21, Professor Clemens  was the Executive Director of the International Centre for Diarrheal Disease Research (icddr,b), and in May, 2021 he returned to the IVI, where he serves as Senior Scientific Advisor to the Director General. Professor. Clemens is the author of over 450 peer-reviewed publications and was the recipient of the 2010 Sabin Gold Medal as well as the 2018 Prince Mahidol Prize in Public Health.

BS, Biology, Stanford University, Stanford, CA
MD, Yale University, New Haven, CT
This faculty member is available to serve as: 
Doctoral Advisor
PhD Committee Member
DrPH Committee Member

Please check with the faculty member or their office about availability to serve during current academic period.

Selected Publications: 

Qadri F, Khanam F, Liu X, Theiss-Nyland K, Biswas PK, Bhuiyan AI, Ahmmed F, Colin-Jones R, Smith N, Tonks S, Voysey M, Mujadidi YF, Mazur O, Rajib NH, Hossen MI, Ahmed SU, Khan A, Rahman N, Babu G, Greenland M, Kelly S, Ireen M, Islam K, O'Reilly P, Scherrer KS, Pitzer VE, Neuzil KM, Zaman K, Pollard AJ, Clemens JD. Protection by vaccination of children against typhoid fever with a Vi-tetanus toxoid conjugate vaccine in urban Bangladesh: a cluster-randomised trial. Lancet. Aug 9:S0140-6736(21)01124-7. doi: 10.1016/S0140-6736(21)01124-7. Epub ahead of print. PMID: 34384540. 2021

Deen J, Clemens JD. Assessment of vaccine herd protection: Lessons learned from cholera and typhoid vaccine trials. Journal of Infectious Diseases. 2021 Jul 17:jiab358. doi: 10.1093/infdis/jiab358. Epub ahead of print. PMID: 34273168. 2021.

Ali M, Qadri F, Kim DR, Islam MT, Im J, Ahmmed F, Khan AI, Zaman K, Marks F, Kim JH, Clemens JD. Effectiveness of a killed whole-cell oral cholera vaccine in Bangladesh: further follow-up of a cluster-randomised trial. Lancet Infectious Diseases. 2021 Jun 16:S1473-3099(20)30781-7. doi: 10.1016/S1473-3099(20)30781-7. Epub ahead of print. PMID: 34146473. 2021.

Kim JH, Marks F, Clemens JD. Looking beyond COVID-19 vaccine phase 3 trials. Nature Medicine. doi: 10.1038/s41591-021-01230-y. Epub ahead of print. 2021.

Qadri F, Ali M, Lynch J, Chowdhury F, Khan AI, Wierzba TF, Excler JL, Saha A, Islam MT, Begum YA, Bhuiyan TR, Khanam F, Chowdhury MI, Khan IA, Kabir A, Riaz BK, Akter A, Khan A, Asaduzzaman M, Kim DR, Siddik AU, Saha NC, Cravioto A, Singh AP, Clemens JD. Efficacy of a single-dose regimen of inactivated whole-cell oral cholera vaccine: Results from 2 years of follow-up of a randomised trial. Lancet Infectious Diseases. Jun;18(6):666-674.  doi:10.1016/S1473-3099(18)30108-7. 2018

Clemens J, Nair GB, Qadri F, Ahmed T, Holmgren J. Cholera. Lancet Sep 23;390(10101):1539-1549. doi:10.1016/S0140-6736(17)30559-7. 2017

Qadri F, Wierzba TF, Ali M, Chowdhury F, Khan AI, Saha A,Khan IA, Asaduzzaman M, Akter A, Khan A, Begum YA, Bhuiyan TR, Khanam F, Chowdhury MI, Islam T, Chowdhury AI, Rahman A, Siddique SA, You YA, Kim DR, Siddik AU, Saha NC, Kabir A, Cravioto A, Desai SN, Singh AP, Clemens JD. Efficacy of a single-dose, inactivated oral cholera vaccine in Bangladesh. New England Journal of Medicine. 374(18):1723 32. doi: 10.1056/NEJMoa1510330. 2016.

Qadri F, Ali M, Chowdhury F, Khan A, Saha A, Khan I, Begum Y, Bhuiyan T, Chowdhury M, Uddin M, Khan J, Chowdhury A,  Rahman A, Siddique S, Asaduzzaman M, Akter A, Khan M,You Y, SiddikM,  Saha N, Kabir A, Riaz B, Biswas S, Begum F, Unicomb L, Luby S, Cravioto A, Clemens J. Feasibility and effectiveness of oral cholera vaccine in an urban endemic setting in Bangladesh: A cluster randomised open-label trial. Lancet. 386: 1362-71. doi: 10.1016/S0140-6736(15)61140-0. 2015.

Bhattacharya S, Sur D, Ali M, Kanunga S, You Y, Manna B, Sah B, Nyogi S, Park J, Sarkar B, Puri M, Kim D, Deen J, Holmgren J, Carbis R, Dingra M, Donner A, Nair G, Lopez A, Wierzba T, Clemens J. 5 year efficacy of a bivalent killed whole cell oral cholera vaccine in Kolkata, India: A cluster randomized, double-blind, placebo-controlled trial. Lancet Infectious Disease.  13: 1050-6. 2013.

Maskery B, DeRoeck D, Levin A, Kim YE, Wierzba T, Clemens J. Strategy, demand, management and costs of an international cholera vaccine stockpile. Journal of Infectious Diseases. 208 (Suppl 1): S15-22, 2013.

Clemens J, Shin S, Ali M. New approaches to the assessment of vaccine herd protection in vaccine trials. Lancet Infectious Diseases. 11: 482-7, 2011.