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Front. Genet., 02 June 2021 |

Correlation Between SARS-Cov-2 Vaccination, COVID-19 Incidence and Mortality: Tracking the Effect of Vaccination on Population Protection in Real Time

  • 1KAB Group, Goncalo Moniz Institute, Oswaldo Cruz Foundation, Salvador, Brazil
  • 2Multinational Organization Network Sponsoring Translational and Epidemiological Research Initiative, Salvador, Brazil
  • 3Center of Data and Knowledge Integration for Health, Oswaldo Cruz Foundation, Salvador, Brazil

Coronavirus disease 19 (COVID-19) has struck the world since the ending of 2019. Tools for pandemic control were scarce, limited only to social distance and face mask usage. Today, upto 12 vaccines were approved and the rapid development raises questions about the vaccine efficiency. We accessed the public database provided by each country and the number of death, active cases, and tests in order to evaluate how the vaccine is influencing the COVID-19 pandemic. We observed distinct profiles across the countries and it was related to the vaccination start date and we are proposing a new way to manage the vaccination.


A new SARS-Cov-2 associated disease is commonly known as coronavirus disease 19 (COVID-19) and present as a spectrum of clinical manifestations ranging from asymptomatic, minor flu-like symptoms to acute respiratory distress syndrome, pneumonia, and death (Sharma et al., 2020). Rapidly, the COVID-19 became a worldwide public health emergency and several attempts to control its dissemination were proposed by non- pharmacological interventions. The most used interventions were social distancing and the use of face masks, since there was no antiviral treatment or any effective vaccine (Randolph and Barreiro, 2020). In the last year, several vaccine candidates were in development, as a result of the great effort to contain the pandemic. However, due to the rapid vaccine development, uncertain questions have been raised in common media, such as the vaccine production capacity to attempt the global demand and its efficacy (Chen, 2020). The emergencial development of COVID-19 vaccines occurred extremely fast, integrating various tools and vaccine platforms. In the future, this technology will be useful to quickly develop vaccines against other new emerging diseases (Hodgson, 2020). Each government must have its own platform for vaccination tracking, in order to perform the monitoring of vaccine coverage and to early identification of possible adverse effects (Hanney et al., 2020). In 2020, we developed a recursive sub-typing screening surveillance system able to perform automated genomic surveillance accessing all the sequences deposited in different repositories for mining, subtyping and performing a genomic surveillance. This system was also able to evaluate the vaccination profile in Brazil by accessing the global vaccination program dataset. As a result the system was able to identify new zika lineage occurrences (Kasprzykowski et al., 2020) and revealed a decrease in children vaccination in the last years in Brazil (Césare et al., 2020). Given the relevance of the SARS-Cov-2 pandemic, we adapted our system to track the association between implementation of vaccines, occurrence of new cases and mortality over time.

Materials and Methods

To evaluate the COVID-19 vaccination, we developed an application of this tool to real-time access a public access COVID-19 database provided in a cross-country database of COVID-19 (Hasell et al., 2020). CaVaCo (Cases, Vaccinations, and COVID-19) tool allows us to retrieve the COVID-19 cases, deaths and vaccination data to compare and correlate countries vaccination coverage with other parameters. The tool was developed in R (Wickham and Grolemund, 2016), powered to download and standardize the data automatically. As a result the correlation between number of daily vaccines by number of new cases, number of new deaths and number of tests is performed, using the spearman correlation. To access the real-time tool, access:


So far (April 23, 2021), there are 10 vaccines approved and being used worldwide (until: CanSino, Covaxin, EpiVacCorona, Johnson & Johnson, Moderna, Oxford/AstraZeneca, Pfizer/BioNTech, Sinopharm, Sinovac, and Sputnik V). From the 193 countries that started vaccination (List of countries below) the majority have started the vaccination program using Oxford/AstraZeneca vaccine (n = 135, 37.9%) while 25% had chosen the Pfizer/BioNTech and 10.4% Moderna and the remaining 26.7% used CanSino, Covaxin, EpiVacCorona, Johnson & Johnson, Sinopharm, Sinovac, and Sputnik V (Figure 1). Using the date available up to April 23, 2021, we performed a correlation analysis between the numbers of new cases with the daily vaccinations. As a result, 60 countries presented positive correlations (Table 1) and 27 countries with negative correlation (Table 1). Despite the vaccination, the number of new cases has been still increasing in these countries. This finding reinforces the need to keep social distance and the use of face masks recommendations to reduce the virus transmission. In other hand the decreasing number of vaccinations and cases can depict a positive correlation and the number of days and the percent of vaccine population could inform how successfully the vaccination program is going. These recommendations should be employed until at least the immunization starts to show a significant reduction in the number of cases (Ahmed et al., 2021). The countries with negative correlation started to have a reduction in the number of new cases and the vaccination should maintain the decreasing number of cases, since the isolation alone is not able to control the COVID-19 (Hellewell et al., 2020). The same approach has employed with the number of new deaths and we observed 37 countries with positive correlations and 33 countries have negative correlations (Table 1). These results show that implementation of vaccines is not the final solution and the maintenance of the non-pharmacological interventions should not be abandoned once the increase of new cases and deaths are indicating the population remains vulnerable to SARS- COV2 infection (Billon-Denis and Tournier, 2020). On the other hand, the negative correlation in certain countries point to a success en route to the vaccination program in reducing both the COVID-19 cases and related deaths. Only 5 countries have positive correlation between the number of vaccination and the number of tests positive for COVID-19 in February 2, 2021 (This data was discontinued). These countries remained testing the population even though the vaccination started. Only Sweden presented a negative correlation (Supplementary Table 1). This approach is useful for pandemic surveillance and the stop of population testing is dangerous and does not prevent the identification of new waves (Holt, 2021). The correlation between the cases/deaths and the vaccination numbers could be a powerful indicator of disease control, since a certain coverage is required for population protection. The continuous follow up of the correlation patterns from the beginning of the vaccination can be used to track the immunization program in each country. Additionally with the genomic surveillance can reveal how the vaccine responds against the introduction of new COVID-19 variants, as previously described (Korber et al., 2020). The present study has some limitations, such as the heterogeneity of strategies applied by the different countries indicated that an individual analysis of specific countries should be performed to evaluate in more granularities the distinct epidemiologic situations, to minimize this effect the number of days used in the correlation analysis are depicted in the table. Some countries displayed substantial missing data or discontinue measuring few variables, like the number of test to COVID-19 in their database. This analysis uses numerical measurements and it cannot reflect the entire national behavior or public politics. Also the present analysis cannot handle or correct numeric bias or outlier interferences. However, taking together these data and applying statistics methods allowed us to monitor the vaccination process in countries or in sub national units. Recursive evaluation of immunization and COVID-19 morbimortality has potential to provide a unique tool to aid decision-making strategies to overcome the current pandemic.


Figure 1. Worldwide distribution of vaccines. (A) Proportional of usage of vaccines by countries represented in a sector graph. (B) Daily distribution in all countries with a top six countries highlighted.


Table 1. Correlation between the numbers of vaccines against the number of new cases and new deaths in the country have started the vaccination.

Data Availability Statement

The original contributions presented in the study are included in the article/Supplementary Material, further inquiries can be directed to the corresponding author.

Author Contributions

KF and AQ performed data acquisition and analysis. KF, BA, and AQ performed the results interpretation. All authors wrote the manuscript, contributed to the article, and approved the submitted version.

Conflict of Interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Supplementary Material

The Supplementary Material for this article can be found online at:


Ahmed, I., Ahmad, M., Rodrigues, J. J. P. C., Jeon, G., and Din, S. (2021). A deep learning-based social distance monitoring framework for COVID-19. Sustain. Cities Soc. 65:102571. doi: 10.1016/j.scs.2020.102571

PubMed Abstract | CrossRef Full Text | Google Scholar

Billon-Denis, E., and Tournier, J.-N. (2020). [COVID-19 and vaccination: a global disruption]. Med. Sci. 36, 1034–1037.

Google Scholar

Césare, N., Mota, T. F., Lopes, F. F. L., Lima, A. C. M., Luzardo, R., Quintanilha, L. F., et al. (2020). Longitudinal profiling of the vaccination coverage in Brazil reveals a recent change in the patterns hallmarked by differential reduction across regions. Int. J. Infect. Dis. 98, 275–280. doi: 10.1016/j.ijid.2020.06.092

PubMed Abstract | CrossRef Full Text | Google Scholar

Chen, W. (2020). Promise and challenges in the development of COVID-19 vaccines. Hum. Vaccin. Immunother. 16, 2604–2608. doi: 10.1080/21645515.2020.1787067

PubMed Abstract | CrossRef Full Text | Google Scholar

Hanney, S. R., Wooding, S., Sussex, J., and Grant, J. (2020). From COVID-19 research to vaccine application: why might it take 17 months not 17 years and what are the wider lessons? Health Res. Policy Syst. 18:61.

Google Scholar

Hasell, J., Mathieu, E., Beltekian, D., Macdonald, B., Giattino, C., Ortiz-Ospina, E., et al. (2020). A cross-country database of COVID-19 testing. Sci. Data 7:345.

Google Scholar

Hellewell, J., Abbott, S., Gimma, A., Bosse, N. I., Jarvis, C. I., Russell, T. W., et al. (2020). Feasibility of controlling COVID-19 outbreaks by isolation of cases and contacts. Lancet Glob. Health 8, e488–e496.

Google Scholar

Hodgson, J. (2020). The pandemic pipeline. Nat. Biotechnol. 38, 523–532. doi: 10.1038/d41587-020-00005-z

PubMed Abstract | CrossRef Full Text | Google Scholar

Holt, E. (2021). COVID-19 testing in Slovakia. Lancet Infect. Dis. 21:32. doi: 10.1016/s1473-3099(20)30948-8

CrossRef Full Text | Google Scholar

Kasprzykowski, J. I., Fukutani, K. F., Fabio, H., Fukutani, E. R., Costa, L. C., Andrade, B. B., et al. (2020). A recursive sub-typing screening surveillance system detects the appearance of the ZIKV African lineage in Brazil: is there a risk of a new epidemic? Int. J. Infect. Dis. 96, 579–581. doi: 10.1016/j.ijid.2020.05.090

PubMed Abstract | CrossRef Full Text | Google Scholar

Korber, B., Fischer, W. M., Gnanakaran, S., Yoon, H., Theiler, J., Abfalterer, W., et al. (2020). Tracking Changes in SARS-CoV-2 Spike: evidence that D614G Increases Infectivity of the COVID-19 Virus. Cell 182, 812–827.e19.

Google Scholar

Randolph, H. E., and Barreiro, L. B. (2020). Herd Immunity: understanding COVID-19. Immunity 52, 737–741. doi: 10.1016/j.immuni.2020.04.012

PubMed Abstract | CrossRef Full Text | Google Scholar

Sharma, O., Sultan, A. A., Ding, H., and Triggle, C. R. (2020). A Review of the Progress and Challenges of Developing a Vaccine for COVID-19. Front. Immunol. 11:585354. doi: 10.3389/fimmu.2020.585354

PubMed Abstract | CrossRef Full Text | Google Scholar

Wickham, H., and Grolemund, G. (2016). R for Data Science: import, Tidy, Transform, Visualize, and Model Data. United States: O’Reilly Media, Inc.

Google Scholar

Keywords: COVID19, vaccine, worldwide, epidemiology, virosis

Citation: Fukutani KF, Barreto ML, Andrade BB and Queiroz ATL (2021) Correlation Between SARS-Cov-2 Vaccination, COVID-19 Incidence and Mortality: Tracking the Effect of Vaccination on Population Protection in Real Time. Front. Genet. 12:679485. doi: 10.3389/fgene.2021.679485

Received: 14 March 2021; Accepted: 06 May 2021;
Published: 02 June 2021.

Edited by:

Nimisha Ghosh, Siksha O Anusandhan University, India

Reviewed by:

Gustavo Fioravanti Vieira, Universidade La Salle Canoas, Brazil
Ruchi Tiwari, Pranveer Singh Institute of Technology PSIT, India

Copyright © 2021 Fukutani, Barreto, Andrade and Queiroz. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

*Correspondence: Artur T. L. Queiroz,

These authors have contributed equally to this work