Skip to main content Accessibility help
×
Home
Hostname: page-component-684899dbb8-plzwj Total loading time: 0.387 Render date: 2022-05-16T23:25:45.403Z Has data issue: true Feature Flags: { "shouldUseShareProductTool": true, "shouldUseHypothesis": true, "isUnsiloEnabled": true, "useRatesEcommerce": false, "useNewApi": true }

Vaccination remains the first choice to control the spread of delta and other variants of severe acute respiratory coronavirus virus 2 (SARS-CoV-2)

Published online by Cambridge University Press:  06 August 2021

Qiwei Liang
Affiliation:
Children’s Hospital of Anhui Medical University, Hefei, Anhui, China Department of Epidemiology and Health Statistics, School of Public Health, Anhui Medical University, Hefei, Anhui, China
Chenyu Sun*
Affiliation:
Internal Medicine, AMITA Health Saint Joseph Hospital Chicago, Chicago, Illinois, United States
Haixia Liu
Affiliation:
Department of Epidemiology and Health Statistics, School of Public Health, Anhui Medical University, Hefei, Anhui, China
Xiuping Zhang
Affiliation:
Children’s Hospital of Anhui Medical University, Hefei, Anhui, China
Mubashir Ayaz Ahmed
Affiliation:
Internal Medicine, AMITA Health Saint Joseph Hospital Chicago, Chicago, Illinois, United States
Sudha Misra
Affiliation:
Internal Medicine, AMITA Health Saint Joseph Hospital Chicago, Chicago, Illinois, United States
John Patrick N. Uy
Affiliation:
Infectious Disease and International Health, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, United States
Mohammad Baseem Shaikh
Affiliation:
Hospital Medicine, University of Kentucky Albert B. Chandler Hospital, Lexington, Kentucky, United States
*
Author for correspondece: Dr Chenyu Sun, E-mail: drsunchenyu@yeah.net
Rights & Permissions[Opens in a new window]

Abstract

Type
Letter to the Editor
Copyright
© The Author(s), 2021. Published by Cambridge University Press on behalf of The Society for Healthcare Epidemiology of America

To the Editor—Since severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) first entered the population, the massive and rapid spread of the coronavirus disease 2019 (COVID-19) pandemic has led to the emergence of many variants, resulting in genetic diversity. Currently, there are 4 globally recognized variants of concern (VOCs). 1 Among them, the delta VOC has spread to >80 countries worldwide; it is even more transmissible than other variants and becoming the dominant strain of the disease worldwide. 2

Safe and effective vaccines are significant tool to control the pandemic. As of July19, >340 million doses have been administered globally and >169 countries have reported vaccinations. 3 Recently, the Public Health England study found that people who have had 1 vaccine dose are 75% less likely to be hospitalized by the delta VOC compared with unvaccinated individuals. In addition, recent studies conducted in Europe showed that both the Oxford–AstraZeneca and Pfizer–BioNTech COVID-19 vaccines were effective in reducing the risk of SARS-CoV-2 infection and COVID-19 hospitalization in people infected with the delta VOC. Reference Callaway4 Although the vaccines protect well against severe disease and death, they may not effectively prevent spreading COVID-19 to others. The association between vaccination and the spread of the delta VOC has caught our attention.

First, the delta VOC has moderate resistance to the vaccine. Compared with the alpha variant, the effectiveness of the COVID-19 vaccine against the delta VOC decreased. According to Israel Ministry of Health, the effectiveness of the COVID-19 vaccine in preventing infection and symptomatic illness has decreased to 64% since June 6 with the spread of the delta variant in Israel. 5 Because variants may cause breakthrough cases, vaccinated patients may not present with severe symptom or may even be asymptomatic, leading to transmission in the community, 6 whereas certain populations may have less lasting immunity through vaccination, including elderly patients and patients with certain underlying medical conditions, such as multiple myeloma. Reference Van Oekelen, Gleason and Agte7,Reference Soiza, Scicluna and Thomson8 Moreover, there is also a concern that protective immunity of vaccination may decline after 6 months. 9 All of these could increase the risk of transmission of the delta VOC, especially for people who are not vaccinated, who may be at greater risk under such circumstances. All of these factors contribute to the continuing uncertainty related to the pandemic.

Second, epidemiological analyses indicate that the delta VOC is more infectious. Recent studies suggest that its interactivity is likely to be at least 60% higher than the alpha VOC, with higher risk of transmission to close contacts. Reference Callaway4 Clusters of infection cases may arise among unvaccinated people, which may add to the risk of transmission of the delta VOC.

Third, the imbalance in vaccination rates may increases the risk of delta VOC transmission. Africa, where <2% of the population is vaccinated against SARS-CoV-2, is suffering the worst surge in COVID-19 cases since the pandemic began due to the delta VOC. Not only have hospitalizations increased >40% in recent weeks but also delta VOC has been detected at least 10 countries. Reference Callaway4,10 People in areas with low vaccination rates and insufficient access to vaccines are likely to be most affected by the delta VOC. The more massive and rapid the transmission, the more variants may emerge. 1

In summary, with the emergence of the delta VOC and other new variants, people who are not vaccinated will face greater risk; thus, every effort should be implemented to encourage vaccination and provide access to the vaccines. In addition, wearing a face mask and maintaining social distance in public should still be considered despite vaccination status due to the imminent possible surge of cases secondary to the new variants.

References

Tracking SARS-CoV-2 variants. World Health Organization website. https://www.who.int/en/activities/tracking-SARS-CoV-2-variants/. Published 2021. Accessed July 20, 2021.Google Scholar
WHO says delta COVID variant has now spread to 80 countries and it keeps mutating. CNBC website. https://www.cnbc.com/2021/06/16/who-says-delta-covid-variant-has-now-spread-to-80-countries-and-it-keeps-mutating.html. Published 2021. Accessed July 20, 2021.Google Scholar
WHO coronavirus (COVID-19) dashboard. World Health Organization (WHO) website. https://covid19.who.int/. Published 2021. Accessed July 20, 2021.Google Scholar
Callaway, E. Delta coronavirus variant: scientists brace for impact. Nature 2021;595:1718.Google ScholarPubMed
Decline in vaccine effectiveness against infection and symptomatic illness. Israel Ministry of Health website. https://www.gov.il/en/Departments/news/05072021-03. Published 2021. Accessed July 20, 2021.Google Scholar
COVID-19 vaccine breakthrough case investigation and reporting. Center for Disease Control and Prevention website. https://www.cdc.gov/vaccines/covid-19/health-departments/breakthrough-cases.html. Published 2021. Accessed July 20, 2021.Google Scholar
Van Oekelen, O, Gleason, CR, Agte, S, et al. Highly variable SARS-CoV-2 spike antibody responses to two doses of COVID-19 RNA vaccination in patients with multiple myeloma. Cancer Cell 2021. doi: 10.1016/j.ccell.2021.06.014.Google Scholar
Soiza, RL, Scicluna, C, Thomson, EC. Efficacy and safety of COVID-19 vaccines in older people. Age Ageing 2021;50:279283.Google ScholarPubMed
Pfizer says it’s time for a COVID booster; FDA and CDC say not so fast. Cable News Network website. https://amp.cnn.com/cnn/2021/07/08/health/pfizer-waning-immunity-bn/index.html. Published 2021. Accessed July 20, 2021.Google Scholar
Africa suffers worst surge in COVID cases as delta variant spurs third wave of pandemic. CNBC website. https://www.cnbc.com/2021/07/08/delta-variant-africa-suffers-worst-surge-in-covid-cases-officials-brace-for-third-wave.html?recirc=taboaaolainternal. Published 2021. Accessed July 20, 2021.Google Scholar
You have Access
2
Cited by

Save article to Kindle

To save this article to your Kindle, first ensure coreplatform@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Vaccination remains the first choice to control the spread of delta and other variants of severe acute respiratory coronavirus virus 2 (SARS-CoV-2)
Available formats
×

Save article to Dropbox

To save this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about saving content to Dropbox.

Vaccination remains the first choice to control the spread of delta and other variants of severe acute respiratory coronavirus virus 2 (SARS-CoV-2)
Available formats
×

Save article to Google Drive

To save this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about saving content to Google Drive.

Vaccination remains the first choice to control the spread of delta and other variants of severe acute respiratory coronavirus virus 2 (SARS-CoV-2)
Available formats
×
×

Reply to: Submit a response

Please enter your response.

Your details

Please enter a valid email address.

Conflicting interests

Do you have any conflicting interests? *