Dr. Mahajan is a general physician and public health expert with MD in Community Medicine (MUHS, Nashik; 2012) and doctorate (DrPH) in Epidemiology (University of Pittsburgh, USA; 2017). He has 14 years of work experience including research work in community-based observational and experimental studies in developed as well as developing countries. During his doctoral program (2014 to 2018), he worked in three well-established international cohort studies: (i) The Pittsburgh Epidemiology of Diabetes Complications Study (PI: Dr. Trevor Orchard); (ii) ERA- JUMP study (PI: Dr. Akira Sekikawa); and (iii) SESSA study (PI: Dr. Hirotsugu Ueshima) exploring the determinants of chronic diseases in children, young, middle, and old age community participants from different countries.

Prior to joining ICMR, Dr. Mahajan worked as Assistant Professor at the Public Health Foundation of India (2019-2021). In the capacity of Co-PI, he had secured two extramural grants (£800,000.0) funded by the Medical Research Council, UK: (i) Extending an inter-generational cohort to develop a Multimorbidity research platform in rural and urbanising India; (ii) Explaining the vulnerability of Indians to adverse cardio-metabolic effects of meat intake.

Dr. Mahajan joined the ICMR as a scientist D in July, 2021 and was posted in ICMR-RMRIMS, Patna for 16 months. At the ICMR-RMRIMS, Patna, in the capacity of PI and co-PI, Dr. Mahajan co-ordinated the activities for research studies related to: Animal and Snake bite burden assessment; Mental Health implications of Leishmaniasis; TB Elimination; and the efficacy of Dengue Tetravalent Vaccine. Dr. Mahajan was also the part of the multidisciplinary teams constituted by MOHFW, GOI to assess: the preparedness of state of Bihar for the third wave of COVID-19 (Dec 2021); and COVID-19 vaccination roll-out ( Post Introduction Evaluation, April 2022) for the state of Jharkhand. As a part of capacity building program of the Infectious diseases Data Observatory consortium (developed by the University of Oxford, UK in collaboration with ICMR-NIMR, Delhi), Dr. Mahajan has attended the short course on “Introduction to Mathematical Models of the Epidemiology and Control of Infectious Disease Course” held at the Imperial College, London, UK from September 11 - 23, 2022.

In the month of November 2022, Dr. Mahajan has joined ICMR-NIN, Hyderabad and co-ordinating the research activities for the Dietary & Biomarker Survey-1 (to assess the nutritional and health status of Indians); and the APCAPS cohort (to explore the determinants of multimorbidity and the role of meat consumption in cardiovascular diseases in urbanizing communities).

1. Shrestha R, Singh P, Dhakhwa P, Mahajan H, Operational Research Capacity Building Study Group. Augmenting the Referral Pathway for Retinal Services Among Patients With Diabetes Mellitus at Reiyukai Eiko Masunaga Eye Hospital, Nepal: Protocol for a Nonrandomized, Pre–Post Intervention Study. JMIR Res Protoc. 2021 Dec; 10(12): e33116.
2. Sabherwal S, Chinnakaran A,  Sood I. Mahajan H, Operational Research Capacity Building Study Group. Effect of door-to-door screening and awareness generation activities in the catchment areas of vision centers on service utilization: Protocol for a randomized experimental study. JMIR Res Protoc. 2021; Oct 2.
3. Shrestha M, Bhandari G, Rathi SK, Mahajan H. Operational Research Capacity Building Study Group. Improving the Follow-up Rate for Pediatric Patients (0-16 years) of an Eye Hospital in Nepal: Protocol for a Public Health Intervention Study. JMIR Res Protoc. 2021 Oct 8;10(10):e31578.
4. Mahajan H, Zaid M, Mackey R, et al. Lipoprotein particles and coronary artery calcium in middle-aged US-White and Japanese men. Open Heart  2019;6:e001119.
5. Mahajan H, Choo J, Masaki K, Fujiyoshi A, et al. Serum Long-Chain n-3 Polyunsaturated Fatty Acids and Aortic Calcification in Middle-Aged Men: The Population-Based Cross-sectional ERA-JUMP Study. Nutrition, Metabolism & Cardiovascular Diseases. 2019. Volume 29, Issue 8, 837-846.
6. Sekikawa A, Mahajan H, Miura K, et al. Association of blood levels of marine omega-3 fatty acids with coronary calcification and calcium density in Japanese men. European Journal of Clinical Nutrition. 2018
7. Mahajan H, Choo J, Masaki K, et al. Data on alcohol consumption and coronary artery calcification among asymptomatic middle-aged men for the ERA-JUMP study. Data In Brief. 2018;17:1091-98.
8. Mahajan H, Choo J, Masaki K, et al. Association of Alcohol Consumption and Aortic Calcification in Healthy Men Aged 40-49 Years for the ERA JUMP Study. Atherosclerosis. 2018; 268: 84-91.
9. Miller RG, Mahajan H, Costacou T, et al., Anderson SJ, Orchard TJ. A Contemporary Estimate of Total Mortality and Cardiovascular Disease Risk in Young Adults With Type 1 Diabetes: The Pittsburgh Epidemiology of Diabetes Complications Study. Diabetes Care. 2016; 39(12):2296-30.
10. Nale T, Chavan MK, Mahajan H, Mahajan A.Primary care based interventions are associated with improvement in nutritional status of children: evidence from community based study in India. International Journal of Scientific and Research Publications. 2013; 2(3)
11. Velhal GD, Sawant S, Rao A, Mahajan H. Awareness among nursing staff about roles and responsibilities in a tertiary level health care institute, India. International Journal of General Medicine and Pharmacy. 2013; 2(2):75-80.
12. Nale T, Chavan MK, Mahajan H, Velhal GD. Disentangling the influence of maternal factors on nutritional status of children: community based study in an urban slum of India International Journal of General Medicine and Pharmacy. 2013; 2(1):45-54.
13. Sharma B, Mahajan H, Gill N. Impact of health education on knowledge, attitude, self-care practices and life style modification factors in diabetic patients. International Journal of General Medicine and Pharmacy. 2013; 2(3): 29-38
14. Gill N, Velhal GD, Mahajan H, Sharma B. Treatment Outcome of Tuberculosis in Seropositive Patients in a Tertiary Care Hospital and ART Centre in Mumbai, India. Int J Med Health Sci. 2013; 2(3): 322-330.
15. Solat S, Velhal G, Mahajan H, Rao A, Sharma B. Assessment of awareness about HIV/AIDS and operationalization of interventions in rural population of Raigad district, India. International Journal of Scientific and Research Publications. 2012; 2(11):1-14
16. Pedgaonkar S, Velhal GD, Mahajan H, Sharma B. Awareness about cancer in urban slum population of Mumbai, India. J Dent Med Sci. 2012; 2:1-10.
17. Sharma B, Mahajan H, Suryawanshi SR, Bhondve A. Assessment of Co-Morbidities and Self Esteem in Obese Population of Urban Slum of Mumbai. International Journal of Prevention and Treatment. 2012; 1(4): 61-66.
18. Mahajan H. Kazi Y, Sharma B, Velhal GD. Assessment of KAP, risk factors and associated co-morbidities in hypertensive patients. IOSR Journal of Dental and Medical Sciences. 2012; 1(2):6-14.
19. Mahajan H. Kazi Y, Sharma B, Velhal GD. Health education: An effective intervention in hypertensive patients. International Journal of Recent Trends in Science and Technology. 2012; 4(2): 77-82.
20. Bhavsar S, Mahajan H, Kulkarni R. Maternal and environmental factors affecting the nutritional status of children in Mumbai urban slum. International Journal of Scientific and Research Publications. 2012; 2(11): 2250-3153.
21. Bhavsar S, Mahajan H, Kulkarni R. Assessment of the nutritional status and immunization coverage of Anganwadi children in Rafiq Nagar, Mumbai. Public Health Research. 2012; 2(6): 229-34.
22. Bhavsar S, Mahajan H, Kulkarni R. Impact of health intervention on nutritional status of malnourished children in an urban slum of India. International Journal of Medical and Health Science. 2012; 2(2):176-185.
23. Solat S, Velhal G, Mahajan H, Rao A, Sharma B. Assessment of knowledge and attitude of rural population about HIV/AIDS in Raigad District, India. Journal of Dental and Medical Science. 2012; 1: 31-45.