Subhajit Biswas , Ph.D.

Principal Scientist & Head, Infectious Diseases & Immunology Division
Infectious Diseases and Immunology

Research Focus

Dr.Subhajit Biswas is an Indian virologist. His research interest is directed towards elucidating the molecular details of virus infection and pathogenesis, particularly virus replication; viral protein translation and trafficking; virus genome packaging and virus assembly with the aim of developing novel strategies of diagnosis and intervention (vaccines and antivirals).

Research Interest

  1. Research into Dengue virus diagnostics and antivirals.
  2. Understanding the “Leishmania donovani–Leptomonas seymouri-Lepsey NLV1 virus” triple pathogen interaction in Indian Visceral Leishmaniasis/kala-azar 
  3. Investigate the mechanisms of genesis of occult hepatitis B virus (HBV) infections (OBI), especially OBIs caused by altered production or secretion of HBV surface protein (S protein) or immune escape of the HBV surface antigen (HBsAg).
  4. Elucidate the role of herpesvirus helicase and primase (conserved replication enzymes) in the biology of virus infections and exploitation of these enzymes as targets for antiviral development for human and veterinary medicine.


  • Associate Professor, Academy of Scientific and Innovative Research (AcSIR) (2018-present) 
  • Assistant Professor, Academy of Scientific and Innovative Research (AcSIR) (2014-18) 
  • Senior Lecturer , School of Life Sciences, University of Lincoln, UK (2013-2014) 
  • Lecturer , School of Life Sciences, University of Lincoln, UK (2012-2013)
  • Post-doctoral Research Associate, School of Biological Sciences; School of Clinical Medicine, University of Cambridge, UK (2008-2012) 
  • Ph.D. (Cambridge Nehru Scholar), University of Cambridge, UK, (2004-2008) 
  • Member, Microbiology Society, UK
  • M.V.Sc. (Virology, IVRI, Mukteswar) 
  • Masters Degree Topper, Indian Veterinary Research Institute (IVRI), 2003 
  • ICAR-JRF: All India Rank-1, Veterinary Science Group, 2001 
  • B.V.Sc. & A.H. (WBUAFS, Kolkata); Topper, 2001

Honours & Awards

Our research findings highlighted in Newspapers & other Media




  • “Virus or Us: Who will smile the last?? The Tug-of-War continues……”-Special Webinar Series Lecture by Dr Subhajit Biswas: JIGYASA CSIR, YOUTUBE CHANNEL, delivered on 27th July, 2020.(





  • Citation: Faculty of 1000 Biology: evaluations for Subhajit Biswas et al Arch Virol 2007 Aug 152 (8): Title of paper: Single amino acid substitutions in the HSV-1 helicase protein that confer resistance to the helicase-primase inhibitor, BAY 57-1293 are associated with increased or decreased virus growth characteristics in tissue culture. Archives of Virology, 152, 1489-500. (Evaluated by Prof Donald Coen, Harvard Medical School, USA and selected as “New finding” in Microbiology). (



Grants & Supports

  1. CSIR-Mission Mode Project
  2. SERB, Department of Science and Technology, India
  3. Department of Biotechnology, Government of West Bengal


Patents & Publications


On non-cytopathic herpes simplex virus type-1 isolates from Kolkata, India

1. Roy S, Sukla S, De A, Biswas S*. Non-cytopathic herpes simplex virus type-1 isolated from acyclovir-treated patients with recurrent infections. Scientific Reports 2022 Jan 25;12(1):1345.

Included in the list of Top 100 in Microbiology-2022, by Scientific Reports ( 

2. Supplementary information: (*Corresponding author). Impact factor: 4.996.

3. Drug-resistant herpes viruses that evade immunity”- Research findings highlighted in nature INDIA


On diagnosis of viral diseases 

1. Sukla, S.; Mondal, P.; Biswas, S*.; Ghosh, S*. A Rapid and Easy-to-Perform Method of Nucleic-Acid Based Dengue Virus Diagnosis Using Fluorescence-Based Molecular Beacons. Biosensors 2021, 11, 479. Supplementary Information. (*Corresponding author). Impact factor: 5.519.



1. Sarker S, Dutta C,  Mallick A , Das S, Das Chowdhury C,  De A, Gorai S,  Biswas S* (2023). Pre-dominance of dengue non-cross-reacting SARS-CoV-2 spike antibodies during the Omicron era and their role in the ADE-mediated surge of Dengue virus serotype 3. MedRxiv 2023.09.08.23295136; (*Corresponding author).

2. Dutta D, Ghosh A, Dutta C, Sukla S*, Biswas S* (2023). Cross reactivity of SARS-CoV-2 with other pathogens, especially dengue virus: A historical perspective. J Med Virol. 95: e28557. PMID: 36755367. , Wiley link share to full PDF:    (*Corresponding author). Impact Factor: 20.69.

Our findings published by India Science Wire 

(  and twitted:

3. Biswas S*, Sukla S. COVID-19 virus infection and transmission are observably less in highly Dengue-endemic countries: is pre-exposure to Dengue virus protective against COVID-19 severity and mortality? will the reverse scenario be true? Clinical & Experimental Investigations. 2020; 1 (2). (*Corresponding author).

4. Himadri Nath#, Abinash Mallick#, Subrata Roy, Soumi Sukla, Subhajit Biswas*. Computational modelling supports that dengue virus envelope antibodies can bind to SARS-CoV-2 receptor binding sites: Is pre-exposure to dengue virus protective against COVID-19 severity? Computational and Structural Biotechnology Journal, 2021; 19, Pages 459-466. Impact Factor: 7.271. OSF Preprints. 2020; (*Corresponding author).   
POLICY CITATION: COVID-19 Scientific and Public Health Policy Update (02 February 2021), Africa CDC.

5. Himadri Nath#, Abinash Mallick#, Subrata Roy, Soumi Sukla, Keya Basu, Abhishek De, Subhajit Biswas*. Dengue antibodies can cross-react with SARS-CoV-2 and vice versa-Antibody detection kits can give false-positive results for both viruses in regions where both COVID-19 and Dengue co-exist. medRxiv 2020.07.03.20145797; doi: (*Corresponding author). 
POLICY CITATION: Our first report (globally) (6th July 2020; medRxiv preprint above) that archived Dengue serum samples from 2017 cross-reacted in COVID-19 lateral flow-based strip tests has been cited in "National Guidelines for Dengue Case Management during COVID-19 pandemic" by the Ministry of Health & Family Welfare, Govt. of India. Please see page number 13 and 31 of the Report.

6. Subrata Roy, Himadri Nath, Abinash Mallick, Subhajit Biswas* SARS-CoV-2 has observably higher propensity to accept uracil as nucleotide substitution: Prevalence of amino acid substitutions and their predicted functional implications in circulating SARS-CoV-2 in India up to July, 2020 bioRxiv 2020.10.07.329771; doi: (*Corresponding author).

7. Biswas S*, Sukla S, Roy S, Nath H, Mallick A. Regarding: Masyeni S, Santoso MS, Widyaningsih PD, Wedha Asmara DG, Nainu F, Harapan H, et al. Serological cross-reaction and co-infection of dengue and COVID-19 in Asia: Experience from Indonesia. Int J Infect Dis 2020; 102:152-4. (*Corresponding author). Impact factor: 12.074.

8. Nath H, Mallick A, Roy S, Sukla S, Basu K, De A, Biswas S*. Archived dengue serum samples produced false-positive results in SARS-CoV-2 lateral flow-based rapid antibody tests. J Med Microbiol. 2021 Jun; 70 (6). doi: 10.1099/jmm.0.001369. PMID: 34110279. (*Corresponding author). Impact factor: 3.196.

9.  Nath H, Mallick A, Roy S, Kayal T, Ranjan S, Sengupta S, Sukla S, Biswas S*. COVID-19 serum can be cross-reactive and neutralizing against Dengue virus (DV) as observed by DV neutralization test (2022). Int J Infect Dis. (*Corresponding author). Impact factor: 12.074.


On epidemiology and pathogenesis of flaviviruses like dengue and zika in human and mosquito samples from Eastern India

1. Sukla S#, Ghosh A#, Saha R, De A, Adhya S, Biswas S*(2018). In-depth molecular analysis of a small cohort of human and Aedes mosquito (adults and larvae) samples from Kolkata revealed absence of Zika but high prevalence of dengue virus. Journal of Medical Microbiology, 67, 1109-1119 *Corresponding author; #Joint first authors. Impact factor: 3.196.

2. Himadri Nath, Keya Basu, Abhishek De, Subhajit Biswas*. Dengue virus sustains viability of infected cells by counteracting apoptosis-mediated DNA breakage. bioRxiv 2020.06.19.162479;

3. Anisa Ghosh#, Soumi Sukla#, Himadri Nath, Rajdeep Saha, Abhishek De, Subhajit Biswas * (2022). Non-structural protein 1 (NS1) variants from dengue virus clinical samples revealed mutations that influence NS1 production and secretion. Eur J Clin Microbiol Infect Dis. Online text-only view under Springer Nature SharedIt Initiative:  *Corresponding author; #Joint first authors. Impact factor: 5.1.


On discovery of virus in kala-azar samples from India

1. Soumi Sukla, Syamal Roy, Shyam Sundar, Subhajit Biswas* (2017). Leptomonas seymouri narna-like virus 1 and not leishmaniaviruses detected in kala-azar samples from India. Archives of Virology, 162, 3827-35. Online text-only view under Springer Nature SharedIt Initiative: *Corresponding author. Impact factor: 2.68.

2. Sukla S*, Nath H, Kamran M, Ejazi SA, Ali N, Das P, Ravichandiran V, Roy S, Biswas S* (2022). Detection of Leptomonas seymouri narna-like virus in serum samples of visceral leishmaniasis patients and its possible role in disease pathogenesis. Scientific Reports, Aug 24;12(1): 14436. (*Corresponding author). Impact factor: 4.996.


On human pandemic norovirus contamination of coastline blue mussels in the UK

1. Subhajit Biswas *, Philippa Jackson, Rebecca Shannon, Katherine Dulwich, Soumi Sukla  and Ronald A Dixon  (2017).  Molecular screening of blue mussels indicated high mid-summer prevalence of human genogroup II Noroviruses, including the pandemic “GII.4 2012” variants in UK coastal waters during 2013. Brazilian Journal of Microbiology, 49, 279-84. Impact factor: 2.48.                                 *Corresponding author.


On superior probiotics identified from bacteria of marine origin

1. Palashpriya Das, Suman Khowala, Subhajit Biswas *(2016). In vitro probiotic characterization of Lactobacillus casei isolated from marine samples. LWT - Food Science and Technology, 73, 383-390. *Corresponding author. Impact factor: 4.952.


On occult hepatitis B virus prevalence and mechanisms of escape of immune-detection

1. Das P #, Supekar R #, Chatterjee R, Roy S, Ghosh A, Biswas S*. Hepatitis B virus detected in paper currencies in a densely populated city of India: A plausible source of horizontal transmission? World J Hepatol 2020; 12(10): 775-791. * Corresponding author. # Joint first authors.Impact factor: 3.26.

2. De A, Roy S, Sukla S, Ansari A & Biswas S* (2017). Occult hepatitis B virus infections (often with human herpesvirus 7 co-infection) detected in Pityriasis rosea patients: A pilot study. Indian Journal of Dermatology, 62, 598-605. *Corresponding author Impact factor: 1.49.

3. Biswas S, Candotti D¶  & Allain J-P (2013). Specific amino acid substitutions in the S protein prevent its excretion in vitro and may contribute to occult hepatitis B virus infection. Journal of Virology, 87, 7882-92. Impact Factor: 6.549 ¶ equal contribution.

4. Candotti D, Lin CK, Belkhiri D, Sakuldamrongpanich T, Biswas S, Lin S, Teo D, Ayob Y & Allain J-P (2012). Occult Hepatitis B infection in asymptomatic blood donors from South East Asia: molecular characterization and potential mechanisms of occurrence. Gut-British Medical Journal, 61, 1744-53. Impact Factor: 23.059.


On understanding of rotavirus RNA packaging

1. Biswas S, Li W, Manktelow E, Lever J, Lukavsky PJ, Desselberger U & Lever AM (2014). Physicochemical analysis of rotavirus segment 11 supports a 'modified panhandle' structure and not the predicted alternative tRNA-like structure. Archives of Virology, 159, 235-48. Impact Factor: 2.68.


On herpes simplex virus helicase-primase as a novel target for antiviral chemotherapy

1. Biswas S, Sukla S, Goldner T, Field HJ, Kropeit D, Paulsen D, Welbers A, Ruebsamen-Schaeff H, Zimmermann H & Birkmann A (2014). Pharmacokinetics-pharmacodynamics of the helicase-primase inhibitor pritelivir following treatment of wild-type or pritelivir-resistant virus infection in a murine HSV-1 infection model.  Antimicrobial Agents and Chemotherapy, 58, 3843-52. Impact Factor: 5.938.

2. Sukla S, Biswas S¶, Birkmann A, Lischka P, Ruebsamen-Schaeff  H, Zimmermann H & Field HJ (2010). Effects of therapy using a helicase-primase inhibitor (HPI) in mice infected with deliberate mixtures of wild-type HSV-1 and an HPI-resistant UL5 mutant. Antiviral Research, 87, 67-73. Impact Factor: 10.1  ¶ Joint first author.

3. Sukla S, Biswas S, Birkmann A, Lischka P, Zimmermann H & Field HJ (2010). Mis-match primer-based PCR reveals that helicase-primase inhibitor resistance mutations pre-exist in herpes simplex virus type 1 clinical isolates and are not induced during incubation with the inhibitor. Journal of Antimicrobial Chemotherapy, 65, 1347-52. Impact Factor: 5.758.

4. Biswas S * , Núñez Miguel R, Sukla S & Field HJ (2009).  A mutation in helicase motif IV of herpes simplex virus type 1 UL5 that results in reduced growth in vitro and lower virulence in a murine infection model is related to the predicted helicase structure. Journal of General Virology, 90, 1937-42. Impact Factor: 5.14. *Corresponding author

5. Biswas S, Tiley LS, Zimmermann H, Birkmann A & Field, HJ (2008). Mutations close to functional motif IV in HSV-1 UL5 helicase that confer resistance to HSV helicase-primase inhibitors, variously affect virus growth rate and pathogenicity. Antiviral Research, 80, 81-5. Impact Factor: 10.1.

6. Biswas S, Kleymann G, Swift M, Tiley LS, Lyall J, Aguirre-Hernández J & Field HJ (2008). A single drug-resistance mutation in HSV-1 UL52 primase points to a difference between two helicase-primase inhibitors in their mode of interaction with the antiviral target. Journal of Antimicrobial Chemotherapy, 61, 1044-7. Impact Factor: 5.758.

7. Biswas S, Smith C & Field HJ (2007). Detection of HSV-1 variants highly resistant to the helicase-primase inhibitor BAY 57-1293 at high frequency in two of ten recent clinical isolates of HSV-1. Journal of Antimicrobial Chemotherapy, 60, 274-79. Impact Factor: 5.758.

8. Biswas S, Jennens L & Field HJ (2007). Single amino acid substitutions in the HSV-1 helicase protein that confer resistance to the helicase-primase inhibitor, BAY 57-1293 are associated with increased or decreased virus growth characteristics in tissue culture. Archives of Virology, 152, 1489-500. Impact Factor: 2.68 ¶Citation: Faculty of 1000 Biology/Faculty Opinions: evaluations for S Biswas et al Arch Virol 2007. ( Evaluated by Prof Donald Coen, Harvard Medical School, USA and selected as “New finding” in Microbiology.

9. Biswas S, Swift M & Field HJ (2007). High frequency of spontaneous helicase primase inhibitor (BAY 57-1293) drug resistant variants in certain laboratory isolates of HSV-1. Antiviral Chemistry and Chemotherapy, 18,13-23. Impact factor: 2.89.

10. Biswas S, Jennens L & Field HJ (2007). The helicase primase inhibitor, BAY 57-1293 shows potent therapeutic antiviral activity superior to famciclovir in BALB/c mice infected with herpes simplex virus type 1. Antiviral Research, 75, 30-5. Impact Factor: 10.1.



1. Biswas S, Sukla S & Field HJ (2014). Helicase-primase inhibitors for HSV: looking back to the future of non-nucleoside inhibitors for treating herpesvirus infections. Future Medicinal Chemistry, 6, 45-55. Impact Factor: 4.8.

2. Field HJ & Biswas S (2011). Antiviral drug resistance and helicase-primase inhibitors of herpes simplex virus. Drug Resistance Update, 14, 45-51. Impact Factor: 22.22.

3. Biswas S & Field HJ (2008). Pointer: Herpes simplex virus helicase-primase inhibitors: recent findings from the study of drug-resistance mutations. Antiviral Chemistry and Chemotherapy, 19, 1-6. Impact factor: 2.89.

4. Field HJ, Biswas S & Mohammad IT (2006).  Herpesvirus latency and therapy-From a veterinary perspective (Mini-review). Antiviral Research, 71, 127-33. Impact Factor: 10.1.



Biswas S & Field HJ (2011). Helicase-primase inhibitors-a new approach to combat herpes simplex  virus and varicella zoster virus. Antiviral Drug Strategies (Wiley-VCH Verlag GmbH & Co. KGaA), Chapter 6, 129-46.


On molecular epidemiology of foot-and-mouth disease virus (FMDV) in India

1. Mohapatra JK, Sanyal A, Hemadri D, Tosh C, Biswas S, Knowles NJ, Rasool TJ, Bandyopadhyay SK & Pattnaik B (2008). Comparative genomics of serotype Asia 1 foot-and-mouth disease virus isolates from India sampled over the last two decades. Virus Research, 136, 16-29. Impact Factor: 6.286.

2. Biswas S, Sanyal A, Hemadri D, Tosh C, Mohapatra JK, Kumar RM & Bandyopadhyay SK (2006). Sequence analysis of the non-structural 3A and 3C protein-coding regions of foot-and-mouth disease virus serotype Asia1 field isolates from an endemic country. Veterinary Microbiology, 116, 187-93. Impact Factor: 3.246.

3. Biswas S, Sanyal A, Hemadri D, Tosh C, Mohapatra JK, Kumar RM & Bandyopadhyay SK (2005). Genetic comparison of large fragment of the 5'untranslated region among foot-and-mouth disease viruses with special reference to serotype Asia1. Archives of Virology, 150, 2217-39. Impact Factor: 2.68.

4. Sanyal A, Mohapatra JK, Kumar RM, Biswas S, Hemadri D, Tosh C, Sabarinath GP, Gupta SK, Mittal M, Giridharan P & Bandyopadhyay S (2004). Complete nucleotide sequence analysis of a vaccine strain (IND 491/97) and a field-isolate of foot-and-mouth disease virus serotype Asia 1 with an insertion in VP1 protein. Acta Virologica, 48, 159-66. Impact Factor: 1.82.

5. Biswas S, Sanyal A, Hemadri D, Tosh C, Gupta SK, Mittal M, Mohapatra JK, Sabarinath GP, Kumar RM & Bandyopadhyay SK (2004). Sequence analysis of VPg protein of Asia1 field isolates of foot-and-mouth disease virus in India. Journal of Animal and Veterinary Advances, 3, 522-26.


Link to publications in Pubmed