Published: 2021-07-27

COVID-19: sudden and dramatic upsurge in the number of cases in India

Ketul S. Barot, Saloni H. Naik, Mehrie H. Patel, Saptak P. Mankad, Akash A. Patel, Pankti S. Pandya, Vishwa V. Patel, Somashekhar M. Nimbalkar


The second wave of coronavirus disease 2019 (COVID-19) in India, which commenced in March’21, continues to create a major crisis of medications, hospital beds, oxygen, and Intensive Care Units at very rapid rate which has placed the country on the verge of a humanitarian crisis. While no definite treatment for SARS-CoV-2 has been found, different types of vaccines have been manufactured which have shown some effectiveness in preventing disease progression and severity. The objective of this manuscript is to review the available data from the pandemic and highlight the factors that have contributed to the development of second wave in India which has led to crisis. In this review, using available scientific literature on various indexes such as PubMed, Google Scholar, Medline and news articles- where appropriate, we dive into understanding newer virus variants, vaccines and their effectiveness against new strains, overwhelming burden on the Indian healthcare system and socio-politico-environmental factors responsible for upsurge. The sudden upsurge in the number of cases is multifactorial, which includes virus variants, complacency in following COVID-19 appropriate behaviour, burden over the health care system, various socio-politico-environmental factors. As the definitive treatment is yet to be discovered, vaccination remains at the top. 


COVID-19, Second wave, India, Upsurge, Vaccine, Healthcare burden

Full Text:



Darby, A. C., & Hiscox, J. A. (2021). Covid-19: variants and vaccination. BMJ (Clinical research ed.), 372, n771.

Bhatt, N. (2021, April 24). 'The horror is real': India faces oxygen crisis alongside world's highest COVID-19 caseload. The Globe and Mail.

Srivastava, S., Banu, S., Singh, P., Sowpati, D. T., & Mishra, R. K. (2021). SARS-CoV-2 genomics: An Indian perspective on sequencing viral variants. Journal of biosciences, 46(1), 22.

Mahase E. (2021). Covid-19: What new variants are emerging and how are they being investigated?. BMJ (Clinical research ed.), 372, n158.

Fontanet, A., Autran, B., Lina, B., Kieny, M. P., Karim, S., & Sridhar, D. (2021). SARS-CoV-2 variants and ending the COVID-19 pandemic. Lancet (London, England), 397(10278), 952–954.

Farrer, M. (2021, April 21). Why is India seeing such a huge surge in Covid-19 cases? The Guardian.

Naqvi, A. A. T., Fatima, K., Mohammad, T., Fatima, U., Singh, I. K., Singh, A., Atif, S. M., Hariprasad, G., Hasan, G. M., & Hassan, Md. I. (2020). Insights into SARS-CoV-2 genome, structure, evolution, pathogenesis and therapies: Structural genomics approach. Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease, 1866(10), 165878.

CDC. (2020, February 11). Coronavirus Disease 2019 (COVID-19). Centers for Disease Control and Prevention.

Thiagarajan, K. (2021). Why is India having a covid-19 surge? BMJ, 373, n1124.

Indian SARS-CoV-2 Genomic Consortia (INSACOG) | Department of Biotechnology. (n.d.). Retrieved May 12, 2021, from

Cherian, S., Potdar, V., Jadhav, S., Yadav, P., Gupta, N., Das, M., Das, S., Agarwal, A., Singh, S., Abraham, P., Panda, S., Mande, S., Swarup, R., Bhargava, B., Bhushan, R., Team, N. I. C., & Consortium, I. (Unpublished results). Convergent evolution of SARS-CoV-2 spike mutations, L452R, E484Q and P681R, in the second wave of COVID-19 in Maharashtra, India. BioRxiv, 2021.04.22.440932.

Tracking Changes in SARS-CoV-2 Spike: Evidence that D614G Increases Infectivity of the COVID-19 Virus: Cell. (n.d.). Retrieved May 3, 2021, from

Volz, E., Hill, V., McCrone, J. T., Price, A., Jorgensen, D., O’Toole, Á., Southgate, J., Johnson, R., Jackson, B., Nascimento, F. F., Rey, S. M., Nicholls, S. M., Colquhoun, R. M., Filipe, A. da S., Shepherd, J., Pascall, D. J., Shah, R., Jesudason, N., Li, K., … Connor, T. R. (2021). Evaluating the Effects of SARS-CoV-2 Spike Mutation D614G on Transmissibility and Pathogenicity. Cell, 184(1), 64-75.e11.

Yurkovetskiy, L., Wang, X., Pascal, K. E., Tomkins-Tinch, C., Nyalile, T. P., Wang, Y., Baum, A., Diehl, W. E., Dauphin, A., Carbone, C., Veinotte, K., Egri, S. B., Schaffner, S. F., Lemieux, J. E., Munro, J. B., Rafique, A., Barve, A., Sabeti, P. C., Kyratsous, C. A., … Luban, J. (2020). Structural and Functional Analysis of the D614G SARS-CoV-2 Spike Protein Variant. Cell, 183(3), 739-751.e8.

Sarkar, R., Banerjee, A., Dutta, S., & Chawla-Sarkar, M. (Unpublished results). Emergence of SARS-CoV-2 stains harbouring the signature mutations of both A2a and A3 clade. MedRxiv, 2021.02.04.21251117.

Deng, X., Garcia-Knight, M. A., Khalid, M. M., Servellita, V., Wang, C., Morris, M. K., Sotomayor-González, A., Glasner, D. R., Reyes, K. R., Gliwa, A. S., Reddy, N. P., Martin, C. S. S., Federman, S., Cheng, J., Balcerek, J., Taylor, J., Streithorst, J. A., Miller, S., Kumar, G. R., … Chiu, C. Y. (Unpublished results). Transmission, infectivity, and antibody neutralization of an emerging SARS-CoV-2 variant in California carrying a L452R spike protein mutation. MedRxiv, 2021.03.07.21252647.

Jangra, S., Ye, C., Rathnasinghe, R., Stadlbauer, D., Alshammary, H., Amoako, A. A., Awawda, M. H., Beach, K. F., Bermúdez-González, M. C., Chernet, R. L., Eaker, L. Q., Ferreri, E. D., Floda, D. L., Gleason, C. R., Kleiner, G., Jurczyszak, D., Matthews, J. C., Mendez, W. A., Mulder, L. C. F., … Schotsaert, M. (2021). SARS-CoV-2 spike E484K mutation reduces antibody neutralisation. The Lancet Microbe, 0(0).

Tortorici, M. A., Beltramello, M., Lempp, F. A., Pinto, D., Dang, H. V., Rosen, L. E., McCallum, M., Bowen, J., Minola, A., Jaconi, S., Zatta, F., De Marco, A., Guarino, B., Bianchi, S., Lauron, E. J., Tucker, H., Zhou, J., Peter, A., Havenar-Daughton, C., … Veesler, D. (2020). Ultrapotent human antibodies protect against SARS-CoV-2 challenge via multiple mechanisms. Science (New York, N.Y.), 370(6519), 950–957.

Kumar, V., Singh, J., Hasnain, S. E., & Sundar, D. (Unpublished results). Possible link between higher transmissibility of B.1.617 and B.1.1.7 variants of SARS-CoV-2 and increased structural stability of its spike protein and hACE2 affinity. BioRxiv, 2021.04.29.441933.

GISAID - India. (n.d.). Retrieved May 17, 2021, from

Regeneron COVID-19 Dashboard. (n.d.). Retrieved May 17, 2021, from

Forni, G., & Mantovani, A. (2021). COVID-19 vaccines: Where we stand and challenges ahead. Cell Death & Differentiation, 28(2), 626–639.

COVID-19 vaccines. (n.d.). Retrieved May 14, 2021, from

Vaccine information, ICMR New delhi—COVID-19 Vaccine. (n.d.). Retrieved May 19, 2021, from

About the Oxford COVID-19 vaccine. (n.d.). Retrieved May 23, 2021, from

Knoll, M. D., & Wonodi, C. (2021). Oxford–AstraZeneca COVID-19 vaccine efficacy. The Lancet, 397(10269), 72–74.

Mallapaty, S., & Callaway, E. (2021). What scientists do and don’t know about the Oxford–AstraZeneca COVID vaccine. Nature, 592(7852), 15–17.

Sputnik V, Covishield, Covaxin: What we know about India’s Covid-19 vaccines—BBC News. (n.d.). Retrieved May 15, 2021, from

Press Releases. (n.d.). Retrieved May 17, 2021, from

Yadav, P., Sapkal, G. N., Abraham, P., Deshpande, G., Nyayanit, D., Patil, D. Y., Gupta, N., Sahay, R. R., Shete, A., Kumar, S., Panda, S., & Bhargava, B. (Unpublished results). Neutralization potential of Covishield vaccinated individuals sera against B.1.617.1. BioRxiv, 2021.05.12.443645.

Yadav, P. D., Sapkal, G. N., Abraham, P., Ella, R., Deshpande, G., Patil, D. Y., Nyayanit, D. A., Gupta, N., Sahay, R. R., Shete, A. M., Panda, S., Bhargava, B., & Mohan, V. K. (2021). Neutralization of variant under investigation B.1.617 with sera of BBV152 vaccinees. Clinical Infectious Diseases, ciab411.

Edara, V.-V., Lai, L., Sahoo, M. K., Floyd, K., Sibai, M., Solis, D., Flowers, M. W., Hussaini, L., Ciric, C. R., Bechnack, S., Stephens, K., Mokhtari, E. B., Mudvari, P., Creanga, A., Pegu, A., Derrien-Colemyn, A., Henry, A. R., Gagne, M., Graham, B. S., … Suthar, M. S. (Unpublished results). Infection and vaccine-induced neutralizing antibody responses to the SARS-CoV-2 B.1.617.1 variant. BioRxiv, 2021.05.09.443299.

Singh, A. K., Phatak, S. R., Singh, N. K., Gupta, A., Sharma, A., Bhattacharjee, K., & Singh, R. (Unpublished results). Antibody Response after First-dose of ChAdOx1-nCOV (CovishieldTM®) and BBV-152 (CovaxinTM®) amongst Health Care Workers in India: Preliminary Results of Cross-sectional Coronavirus Vaccine-induced Antibody Titre (COVAT) study. MedRxiv, 2021.04.07.21255078.

Madhi, S. A., Baillie, V., Cutland, C. L., Voysey, M., Koen, A. L., Fairlie, L., Padayachee, S. D., Dheda, K., Barnabas, S. L., Bhorat, Q. E., Briner, C., Kwatra, G., Ahmed, K., Aley, P., Bhikha, S., Bhiman, J. N., Bhorat, A. E., du Plessis, J., Esmail, A., … Izu, A. (0). Efficacy of the ChAdOx1 nCoV-19 Covid-19 Vaccine against the B.1.351 Variant. New England Journal of Medicine, 0(0), null.

Irfan, N., & Chagla, Z. (2021). In South Africa, a 2-dose Oxford/AZ vaccine did not prevent mild to moderate COVID-19 (cases mainly B.1.351 variant). Annals of Internal Medicine.

Emary, K., Golubchik, T., Aley, P. K., Ariani, C. V., Angus, B., Bibi, S., Blane, B., Bonsall, D., Cicconi, P., Charlton, S., Clutterbuck, E. A., Collins, A. M., Cox, T., Darton, T. C., Dold, C., Douglas, A. D., Duncan, C., Ewer, K. J., Flaxman, A. L., Faust, S. N., … Oxford COVID-19 Vaccine Trial Group (2021). Efficacy of ChAdOx1 nCoV-19 (AZD1222) vaccine against SARS-CoV-2 variant of concern 202012/01 (B.1.1.7): an exploratory analysis of a randomised controlled trial. Lancet (London, England), 397(10282), 1351–1362.

Khoury, D.S., Cromer, D., Reynaldi, A. et al. Neutralizing antibody levels are highly predictive of immune protection from symptomatic SARS-CoV-2 infection. Nat Med (2021).

Singh A, Deedwania P, Vinay K, Chowdhury AR, Khanna P (2020) Is India's Health Care Infrastructure Sufficient for Handling COVID 19 Pandemic?. Int Arch Public Health Community Med 4:041.

Golechha, M. (2021). India should ramp up its emergency medicine and critical care infrastructure to combat COVID-19. Postgraduate Medical Journal, 97(1146), 266.

Hospital beds (per 1,000 people)—India | Data. (n.d.). Retrieved May 6, 2021, from

Medical doctors (per 10 000 population). (n.d.). Retrieved May 6, 2021, from

Sharma, N. C. (2020, October 19). India is in throes of community transmission, admits Vardhan. Mint.

Sunil, R., Bhatt, M. T., Bhumika, T. V., Thomas, N., Puranik, A., Chaudhuri, S., & Shwethapriya, R. (2021). Weathering the Storm: Psychological Impact of COVID-19 Pandemic on Clinical and Nonclinical Healthcare Workers in India. Indian Journal of Critical Care Medicine : Peer-Reviewed, Official Publication of Indian Society of Critical Care Medicine, 25(1), 16–20.

Hamid, H., Abid, Z., Amir, A., Rehman, T. U., Akram, W., & Mehboob, T. (2020). Current burden on healthcare systems in low- and middle-income countries: Recommendations for emergency care of COVID-19. Drugs & Therapy Perspectives, 1–3.

Rekha M (2020) COVID-19: Health Care System in India. Health Care: Current Reviews S1:262. doi: 10.35248/2375-4273.20.S1.262.

Schneider, M., Altersberger, M., Binder, C., Hengstenberg, C., & Binder, T. (2021). The COVID-19 burden for health care professionals: Results of a global survey. European Journal of Internal Medicine, 83, 96–98.

Behera, D., Praveen, D., & Behera, M. R. (2020). Protecting Indian health workforce during the COVID-19 pandemic. Journal of Family Medicine and Primary Care, 9(9), 4541–4546.

India rolls out the world’s largest COVID-19 vaccination drive. (n.d.). Retrieved May 20, 2021, from

Risk of Covid-19 spread during ongoing wedding season, say experts. (2021, February 17). Hindustan Times.

Superspreader events like weddings behind new Covid surge: Govt panel. (2021, March 19). Hindustan Times.

Coronavirus in India: Latest Map and Case Count. (n.d.). Retrieved May 20, 2021, from

India Covid crisis: Did election rallies help spread virus? (2021, April 29). BBC News.

Haridwar Kumbh Mela 2021: Gathering starts today—check dates of shahi snan, ganga snan, Covid 19 guidelines and more. (2021, April 1). Zee Business.

Covid-19 vaccination drive for people above the age of 45 begins from today. (2021, April 1). Hindustan Times.

Vaccination of 18-44 year olds takes off in Capital. (2021, May 4). Hindustan Times.

88% of Covid-19 fatalities, 40% of cases in 45+ age group: Govt data. (2020, December 18). Hindustan Times.

Half of Covid patients in Maharashtra under-40, only 18% elderly positive. (n.d.). The New Indian Express. Retrieved May 3, 2021, from