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RE: Why there is a second wave in India?
Prajjval Pratap Singh, Scientist,
Cytogenetics laboratory, Banaras Hindu University, Varanasi, India-221005
Other Contributors:
Gyaneshwer Chaubey, Molecular Anthropologist
(10 April 2021)
Why there is a second wave in India?
Prajjval Pratap Singh1, Gyaneshwer Chaubey1 and BHU Serosurveillance Consortium
1 Cytogenetics laboratory, Department of Zoology, Banaras Hindu University, Varanasi, India-221005
Dear Editor,
Buss et al. 1 have found >50% of seroprevalence among populations of Manaus. Brazil. This study has added a ray of hope to achieve herd immunity. However, we have taken a case of Indian city with >40% of seroprevalence, and shown here that the achieving herd immunity by infection is more hypothetical than real in case of SARS-CoV-2.
The recent steep rise of new cases in India have added a major concern 2. In the light of recent serosurveys in India, it was clear that many of the previous hotspots are saturated with approximately 50% of the seropositive individuals 3,4. With the recent explosion in cases, it has been seen that, most of the new hotspots are least affected, however, old hotspots do have substantial number of cases. Such rapid expansion of COVID-19 cases in India has raised an uncertainty on the existence of antibody among large number of individuals.
To investigate the key reason behind the second wave in India, we have revisited the people who have already shown seroprevalence in our previous survey 4. In addition with that, we have also included ten symptomatic individuals who have been tested with RT-PCR and their antibodies have been positive previously.
In this study, we have retested 100 people with the antibody kit CoviscreenTM from district Varanasi of India. Surprisingly, only seven individuals out of 100 showed seropositivity, suggesting that majority of individuals have lost their antibody within 3-6 months (Fig. 1). The frequency of seroprevalence significantly (p<0.0001) reduced from 0.409 (95% CI 0.362-0.457) to 0.07 (95% CI 0.035-0.068). Nevertheless, reports on other regions of world have also shown variable time estimates about the presence of antibodies after the infection 5–9.
Thus, here we explain the major reason for the second wave in India which is likely due to diminished antibody level from large number of seroprevalent population. One of the major driving component of this resurgence was due to broken wall of immunity landscape, formed during first wave of infection. However, it is less likely for a person to be critical in case of reinfection 10. This should significantly reduce the case fatality ratio in the second wave.
References
1. Buss, L. F. et al. Three-quarters attack rate of SARS-CoV-2 in the Brazilian Amazon during a largely unmitigated epidemic. Science 371, 288–292 (2021).
2. Coronavirus in India: Latest Map and Case Count. https://www.covid19india.org.
3. Murhekar, M. V. et al. SARS-CoV-2 antibody seroprevalence in India, August–September, 2020: findings from the second nationwide household serosurvey. Lancet Glob. Health 9, e257–e266 (2021).
4. Singh, P. P. et al. Estimation of real-infection and immunity against SARS-CoV-2 in Indian populations. medRxiv (2021).
5. Crawford, K. H. et al. Dynamics of neutralizing antibody titers in the months after severe acute respiratory syndrome coronavirus 2 infection. J. Infect. Dis. 223, 197–205 (2021).
6. Hueston, L. et al. The antibody response to SARS-CoV-2 infection. in Open forum infectious diseases vol. 7 ofaa387 (Oxford University Press US, 2020).
7. L’Huillier, A. G. et al. Antibody persistence in the first 6 months following SARS-CoV-2 infection among hospital workers: a prospective longitudinal study. Clin. Microbiol. Infect. (2021).
8. Pradenas, E. et al. Stable neutralizing antibody levels 6 months after mild and severe COVID-19 episodes. Med (2021).
9. Wang, K. et al. Longitudinal dynamics of the neutralizing antibody response to SARS-CoV-2 infection. Clin. Infect. Dis. (2020).
10. Abu-Raddad, L. J. et al. SARS-CoV-2 reinfection in a cohort of 43,000 antibody-positive individuals followed for up to 35 weeks. medRxiv (2021).
https://science.sciencemag.org/c ... e-second-wave-india
https://science.sciencemag.org/content/371/6526/288/tab-e-letters |
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