GK Balasubramani

Contributions to Public Health

Liver disease reduces the effectiveness of the influenza vaccine in preventing hospitalization: I collaborated with Po Han Huang, graduate student, and Richard Zimmerman from the Department of Family Medicine on a CDC-sponsored national clinical trial. Our HAVEN study focused on understanding how effective influenza vaccines are at preventing flu-related hospitalizations, especially among adults with chronic liver disease. We found that liver disease may reduce the protection offered by the vaccine, highlighting the need for targeted preventive strategies for this vulnerable group. 

• Huang PH, Nowalk MP, Zimmerman RK, Olson SM, Talbot HK, Zhu Y, Gaglani M, Murthy K, Monto AS, Martin ET, Silveira FP, Balasubramani GK. Vaccine effectiveness against influenza-associated hospitalizations in adults with liver disease, 2015-2020: US Hospitalized Adult Influenza Vaccine Effectiveness Network (HAIVEN). Human Vaccines and Immunotherapeutics. 2025 Dec;21(1):2457205. doi: 10.1080/ 21645515.2025.2457205. Epub 2025 Jan 28. PMID: 39875316; PMCID: PMC11776484.
• Hughes Kramer K, Zimmerman RK, Haggerty CL, Balasubramani GK, Nowalk MP, Martin ET, Gaglani M, Phillips CH, Belongia E, Chung J, Silveira FP. Effectiveness of the influenza vaccine for preventing laboratory-confirmed influenza infections in outpatient immunocompromised adults, 2017-2018. Human Vaccines and Immunotherapeutics. 2024 Dec 31;20(1):2354013. doi: 10.1080/21645515.2024.2354013. Epub 2024 Jun 19. PMID: 39693194; PMCID: PMC11188783.

Relative vaccine effectiveness (rVE) of the recombinant influenza virus (RIV4): I collaborated with Richard Zimmerman from the Department of Family Medicine on a Sanofi-sponsored project. In this work, we conducted a retrospective test-negative case-control study to evaluate the relative effectiveness of influenza vaccines in preventing hospitalizations. Our findings showed that both the recombinant influenza vaccine (RIV4) and the standard-dose inactivated influenza vaccine (SD-IIV4) effectively reduced influenza-related hospitalizations. Notably, RIV4 provided superior protection compared to SD-IIV4, especially among females, younger adults, and individuals without high-risk conditions.

• Zimmerman RK, Patricia Nowalk M, Dauer K, Clarke L, Raviotta JM, Balasubramani GK. Vaccine effectiveness of recombinant and standard dose influenza vaccines against influenza related hospitalization using a retrospective test-negative design. Vaccine. 2023 Aug 7;41(35):5134-5140. doi: 10.1016/j.vaccine.2023.06.056. Epub 2023 Jul 18. PMID: 37474406; PMCID: PMC10895541.
• Zimmerman RK, Dauer K, Clarke L, Nowalk MP, Raviotta JM, Balasubramani GK. Vaccine effectiveness of recombinant and standard dose influenza vaccines against outpatient illness during 2018-2019 and 2019-2020 calculated using a retrospective test-negative design. Human Vaccines and Immunotherapeutics. 2023 Dec 31;19(1):2177461. doi: 10.1080/ 21645515.2023.2177461. Epub 2023 Feb 21. PMID: 36809982; PMCID: PMC10026862.

Estimating the Burden of Respiratory Syncytial Virus: I collaborated with Mary Patricia Nowalk from the Department of Family Medicine on a Merck-sponsored project where we conducted a retrospective cohort study to estimate the burden of RSV hospitalizations among adults aged 18 and older. I developed a method to generate population-based RSV burden estimates using data from a large health system, supplemented by statewide hospitalization records. These estimates contribute valuable insights for public health policymakers and demonstrate a straightforward approach to producing population-based burden data.

• Nowalk MP, D'Agostino H, Dauer K, Stiegler M, Zimmerman RK, Balasubramani GK. Estimating the burden of adult hospitalized RSV infection including special populations. Vaccine. 2022 Jul 29;40(31):4121-4127. doi: 10.1016/j.vaccine.2022.05.077. Epub 2022 Jun 3. Erratum in: Vaccine. 2022 Oct 6;40(42):6187. doi: 10.1016/j.vaccine.2022.09.027. PMID: 35667912; PMCID: PMC10642722.
• Zimmerman RK, Balasubramani GK, D'Agostino HEA, Clarke L, Yassin M, Middleton DB, Silveira FP, Wheeler ND, Landis J, Peterson A, Suyama J, Weissman A, Nowalk MP. Population-based hospitalization burden estimates for respiratory viruses, 2015-2019. Influenza Other Respiratory Viruses. 2022 Nov;16(6):1133-1140. doi: 10.1111/irv.13040. Epub 2022 Aug 22. PMID: 35996836; PMCID: PMC9530548.

Concentrate on advancing epidemiological methods: I analyze data and focus on implementing methods from the Hospitalized Adult Influenza Vaccine Effectiveness Network (HAIVEN), applying necessary adjustments, and using Capture-Recapture calculations to estimate the burden of adult influenza. I demonstrated that when appropriately adjusted, the multiplier method provides a more accurate population estimates of influenza burden than estimates based on a single data source. I am also interested in leveraging advanced statistical approaches, including causal mediation frameworks and latent profile analysis, to explore and model the pathways connecting influenza infection, vaccination, and perceived severity. 

• Balasubramani GK, Nowalk MP, Clarke LG, Dauer K, Silveira F, Middleton DB, Yassin M, Zimmerman RK. Using capture-recapture methods to estimate influenza hospitalization incidence rates. Influenza Other Respiratory Viruses. 2022 Mar;16(2):308-315. doi: 10.1111/irv.12924. Epub 2021 Nov 8. PMID: 34750974; PMCID: PMC8818814.
• Balasubramani GK, Nowalk MP, Eng H, Zimmerman RK. Estimating the burden of adult hospitalized RSV infection using local and state data - methodology. Human Vaccines and Immunotherapeutics. 2022 Dec 31;18(1):1958610. doi: 10.1080/21645515.2021.1958610. PMID: 35271432; PMCID: PMC8920185.

Benefit of Selective Laser trabeculoplasty (SLT) on the impact of Glaucoma disease: I had the opportunity to address the critical public health issue by working with Dr. Realini from West Virginia University on the NIH-funded West Indies Glaucoma Laser Trial (WIGLS). In this project, I analyzed data demonstrating that selective laser trabeculoplasty (SLT) monotherapy significantly lowers intraocular pressure (IOP) in Afro-Caribbean patients with primary open-angle glaucoma (POAG). Building on the success of WIGLS, I am currently collaborating with Stephen Wisniewski and Dr. Realini on the ongoing multi-center randomized COAST trial.

• Realini T, Shillingford-Ricketts H, Burt D, Balasubramani GK. West Indies Glaucoma Laser Study (WIGLS): 1. 12-Month Efficacy of Selective Laser Trabeculoplasty in Afro-Caribbeans with Glaucoma. American Journal of Ophthalmology. 2017 Dec;184:28-33. doi: 10.1016/ j.ajo.2017.09.022. Epub 2017 Sep 28. PMID: 28962966; PMCID: PMC5705413.
• Realini T, Shillingford-Ricketts H, Burt D, Balasubramani GK. Long-Term Outcomes of Selective Laser Trabeculoplasty for Open-Angle Glaucoma in the Caribbean. American Journal of Ophthalmology. 2021 Dec;232:83-89. doi: 10.1016/j.ajo.2021.06.012. Epub 2021 Jun 18. PMID: 34153267; PMCID: PMC8634933.

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