Duration of viral shedding and culture positivity with post-vaccination SARS-CoV-2 delta variant infections

Isolation guidelines for SARS-CoV-2 are largely derived from data collected prior to emergence of the delta variant. We followed a cohort of ambulatory patients with post-vaccination breakthrough SARS-CoV-2 infections with longitudinal collection of nasal swabs for SARS-CoV-2 viral load quantification, whole genome sequencing, and viral culture. All delta variant infections (8/8, 100%) in our cohort were symptomatic, compared with 64% (9/14) of non-delta variant infections. Delta variant breakthrough infections were characterized by higher initial viral load, longer duration of virologic shedding by PCR (median 13.5 vs 4 days, hazard ratio [HR] 0.45, 95%CI 0.17-1.17), greater likelihood of replication competent virus at early stages of infection (6/8 [75%] vs 3/14 [23%], P=0.03), and longer duration of culturable virus (median 7 vs 3 days, HR 0.38, 95%CI 0.14-1.02) compared to non-delta variants. Nonetheless, no individuals with delta variant infections had replication competent virus by day 10 after symptom onset or 24 hours after resolution of symptoms. These data support current US Center for Disease Control isolation guidelines and reinforce the importance of prompt testing and isolation among symptomatic individuals with delta variant breakthrough infections. Additional data are needed to evaluate these relationships among asymptomatic and more severe delta variant breakthrough infections.

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Transmission potential of vaccinated and unvaccinated persons infected with the SARS-CoV-2 Delta variant in a federal prison, July-August 2021

10.1101/2021.11.12.21265796 ◽

2021 ◽

Author(s):

Phillip P. Salvatore ◽

Christine C. Lee ◽

Sadia Sleweon ◽

David W. McCormick ◽

Lavinia Nicolae ◽

...

Keyword(s):

Rt Pcr ◽

Federal Prison ◽

Transmission Potential ◽

Vaccination Rates ◽

Viral Shedding ◽

Viral Culture ◽

Culture Positivity ◽

Health Practitioners ◽

Polymerase Chain ◽

Public Health Practitioners

Background The extent to which vaccinated persons who become infected with SARS-CoV-2 contribute to transmission is unclear. During a SARS-CoV-2 Delta variant outbreak among incarcerated persons with high vaccination rates in a federal prison, we assessed markers of viral shedding in vaccinated and unvaccinated persons. Methods Consenting incarcerated persons with confirmed SARS-CoV-2 infection provided mid-turbinate nasal specimens daily for 10 consecutive days and reported symptom data via questionnaire. Real-time reverse transcription-polymerase chain reaction (RT-PCR), viral whole genome sequencing, and viral culture was performed on these nasal specimens. Duration of RT-PCR positivity and viral culture positivity was assessed using survival analysis. Results A total of 978 specimens were provided by 95 participants, of whom 78 (82%) were fully vaccinated and 17 (18%) were not fully vaccinated. No significant differences were detected in duration of RT-PCR positivity among fully vaccinated participants (median: 13 days) versus those not fully vaccinated (median: 13 days; p=0.50), or in duration of culture positivity (medians: 5 days and 5 days; p=0.29). Among fully vaccinated participants, overall duration of culture positivity was shorter among Moderna vaccine recipients versus Pfizer (p=0.048) or Janssen (p=0.003) vaccine recipients. Conclusions As this field continues to develop, clinicians and public health practitioners should consider vaccinated persons who become infected with SARS-CoV-2 to be no less infectious than unvaccinated persons. These findings are critically important, especially in congregate settings where viral transmission can lead to large outbreaks.

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Community-Based Phenotypic Study of Safety, Tolerability, Reactogenicity and Immunogenicity of Emergency-Use-Authorized Vaccines Against COVID-19 and Viral Shedding Potential of Post-Vaccination Infections: Protocol for a prospective study

10.1101/2021.06.28.21256779 ◽

2021 ◽

Author(s):

Irene S Gabashvili

Keyword(s):

Adverse Event Reporting System ◽

Community Based Participatory Research ◽

Adverse Event Reporting ◽

Security And Privacy ◽

World Health ◽

Research Approach ◽

Community Based ◽

Post Vaccination ◽

Viral Shedding ◽

The Us

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) led to a global pandemic that disrupted and impacted lives in unprecedented ways. Within less than a year after the beginning of the COVID-19 pandemic, vaccines developed by several research teams were emergency-use authorized and made their way to distribution sites across the US and other countries. COVID-19 vaccines were tested in clinical trials with thousands of participants before authorization, and were administered to over a billion people across the globe in the following 6 months. Post-authorization safety monitoring was performed using pre-existing systems (such as the World Health Organization's platform VigiBase or US Vaccine Adverse Event Reporting System, VAERS) and newly developed post-vaccination health checkers (such as V-safe in the US). Vaccinated individuals were also posting their experiences on multiple social media groups created on Facebook, Reddit, Telegram and other platforms, but the groups were often removed as "proliferating false claims". These forms of reporting are susceptible to biases and misclassifications and do not reach all vaccinated individuals, raising questions about risks of exacerbating health inequalities as well as security and privacy vulnerabilities. The objective of this paper is to present the protocol for a community-based participatory research approach enabling long-term monitoring of health effects, strengthening community participation via transparent messaging and support, and addressing challenges of transitioning to a new normal.

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