Clin Assoc Prof Helen Oh, MBBS, MMed (Int. Med), FRCP (Edin & Glasgow), is a Senior Consultant, Department of Infectious Disease, Changi General Hospital.
She received her medical degree from National University of Singapore. She received training in adult Infectious Disease from University of British Columbia, Canada, and in molecular diagnostics from the University of Alabama, Birmingham, USA.

She had been the Chairperson of Infection Control Committee, CGH from 1999 to 2014 and was a member of Infection Control Workgroup, Antimicrobial Taskforce from 2009 to 2013.  She is a member of the Technical Advisory Group (TAG) on Immunization and Vaccine preventable diseases, Western Pacific Regional Office, World Health Organisation since 2011.

She was the Chairperson, Expert Committee on Immunization, MOH from 2004 to 2010 and currently serves as a member. She has been Vice president, Infection Control Association (Singapore) since 2000. She was the Chairperson, Clinical Practice Guidelines on the Use of Antibiotics in Adults, 2002 – 2006 and Review Committee for Donor Recipient screening for Blood-borne infections, 2016 – 2017. She was a member, Independent Review Committee, Hepatitis C outbreak SGH, 2015 and is a current member, Expert Committee on COVID-19 Vaccination from 2020.

Her research interests include dengue immunology, nosocomial infections, travel vaccines and adult immunisation.

To this day, it is perceived by many that a vigorous bout of exercise can temporarily suppress immune function. The three principles of the “open window” hypothesis include (i) infection risk is increased after an acute bout of prolonged and vigorous aerobic exercise; (ii) acute bouts of vigorous exercise can lead to a temporary reduction to salivary IgA levels culminating in a higher risk of opportunistic infections; and (iii) transient decreases in the number of peripheral blood immune cells, which occurs in the hours following vigorous exercise, represents a period of immune suppression.

There is evidence that frequent exercises enhances - rather than suppresses – immune competency, and highlight key findings from human vaccination studies (pneumococcal and influenza) which show heightened responses to bacterial and viral antigens following bouts of exercise.  Rationale for selecting 90 minute exercise was based on unpublished findings of demonstrating that 90 minute of exercise results in significant increase of type 1 interferon, interferon alpha production by plasmacytoid dendritic cells upon activation.

Regular physical activity and frequent exercise might limit or delay aging of the immune system, providing further evidence that exercise is beneficial for immunological health across the lifespan.