Unvaccinated and vaccinated have similar viral load in communities high in SARS-CoV-2 delta – News-Medical.Net

A US-based study has recently compared the viral load in vaccinated and unvaccinated individuals who have been infected with the delta variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

The findings reveal that vaccinated and unvaccinated individuals exhibit similar viral loads following delta infection and that vaccine breakthrough cases have the potential to transmit infection to others. The study is currently available on the medRxiv* preprint server.

Study: Vaccinated and unvaccinated individuals have similar viral loads in communities with a high prevalence of the SARS-CoV-2 delta variant. Image Credit: NIAID

Study: Vaccinated and unvaccinated individuals have similar viral loads in communities with a high prevalence of the SARS-CoV-2 delta variant. Image Credit: NIAID

Background

Viral breakthrough infections occur when vaccinated individuals become infected with the pathogen against which the vaccine was developed. Following immunization, ideally, a vaccine is expected to completely inhibiting viral replication by inducing “sterilizing immunity.” However, not all intramuscular vaccines made against respiratory viruses — including the Coronavirus disease 2019 (COVID-19) vaccine — result in sterilizing immunity. These vaccines are expected to provide protection against symptomatic disease, severe disease, and death. In this context, vaccine-mediated reduction in viral load is believed to play an essential role in reducing disease severity and controlling person-to-person viral transmission.

In the current study, the scientists evaluated whether COVID-19 vaccines can reduce viral loads in vaccine breakthrough cases. Specifically, they have compared the viral load in SARS-CoV-2-positive samples collected from 83 individuals in Dane County, Wisconsin, which has exceptionally high vaccine coverage compared to other populated counties in the United States.

Based on the self-reported vaccination status and dates of complete vaccination, the scientists divided the participants into two groups: the fully vaccinated group with 32 individuals and the unvaccinated group with 51 individuals. Then, as a “convenient proxy” of viral load estimation, they used polymerase chain reaction (PCR)-generated threshold cycle (Ct) values to compare viral loads between vaccinated and unvaccinated individuals who have been infected mostly with the SARS-CoV-2 delta variant (B.1.617.2).

The delta variant of SARS-CoV-2, first identified in India, has caused a sharp increase in COVID-19 cases globally. Compared to other viral variants, the delta variant has significantly higher infectivity and is partially resistant to antibody-mediated neutralization.

<img alt="Viral loads for Dane County specimens are independent of vaccination status. A) N1 threshold cycle (Ct) values for SARS-CoV-2-positive specimens grouped by vaccination status. B) N1 Ct values for SARS-CoV-2-positive specimens confirmed to be delta variants by sequencing. In A and B, the horizontal dashed line represents the threshold for consistent recovery of infectious virus as well as our Ct cut-off for sequencing specimens. Sequence data were available only for specimens collected on or before 16 July 2021, not all samples had a Ct < 30, and not all samples with a Ct < 30 sequenced successfully, accounting for the relatively low number of delta confirmed sequences. P-values were calculated by comparing mean Ct values between groups by Welch two sample t-tests. Data from the Dane County cohort are shown." height="1068" src="https://d2jx2rerrg6sh3.cloudfront.net/image-handler/picture/2021/8/ddd387v1.jpg" srcset="https://d2jx2rerrg6sh3.cloudfront.net/image-handler/ts/20210802115339/ri/2044/picture/2021/8/ddd387v1.jpg 2044w, https://d2jx2rerrg6sh3.cloudfront.net/image-handler/ts/20210802115339/ri/1950/picture/2021/8/ddd387v1.jpg 1950w, https://d2jx2rerrg6sh3.cloudfront.net/image-handler/ts/20210802115339/ri/1750/picture/2021/8/ddd387v1.jpg 1750w, https://d2jx2rerrg6sh3.cloudfront.net/image-handler/ts/20210802115339/ri/1550/picture/2021/8/ddd387v1.jpg 1550w, https://d2jx2rerrg6sh3.cloudfront.net/image-handler/ts/20210802115339/ri/1350/picture/2021/8/ddd387v1.jpg 1350w, https://d2jx2rerrg6sh3.cloudfront.net/image-handler/ts/20210802115339/ri/1150/picture/2021/8/ddd387v1.jpg 1150w, https://d2jx2rerrg6sh3.cloudfront.net/image-handler/ts/20210802115339/ri/950/picture/2021/8/ddd387v1.jpg 950w, https://d2jx2rerrg6sh3.cloudfront.net/image-handler/ts/20210802115339/ri/750/picture/2021/8/ddd387v1.jpg 750w, https://d2jx2rerrg6sh3.cloudfront.net/image-handler/ts/20210802115339/ri/550/picture/2021/8/ddd387v1.jpg 550w, https://d2jx2rerrg6sh3.cloudfront.net/image-handler/ts/20210802115339/ri/450/picture/2021/8/ddd387v1.jpg 450w" sizes="(min-width: 1200px) 673px, (min-width: 1090px) 667px, (min-width: 992px) calc(66.6vw – 60px), (min-width: 480px) calc(100vw – 40px), calc(100vw – 30px)" title="Viral loads for Dane County specimens are independent of vaccination status. A) N1 threshold cycle (Ct) values for SARS-CoV-2-positive specimens grouped by vaccination status. B) N1 Ct values for SARS-CoV-2-positive specimens confirmed to be delta variants by sequencing. In A and B, the horizontal dashed line represents the threshold for consistent recovery of infectious virus as well as our Ct cut-off for sequencing specimens. Sequence data were available only for specimens collected on or before 16 July 2021, not all samples had a Ct < 30, and not all samples with a Ct

Viral loads for Dane County specimens are independent of vaccination status. A) N1 threshold cycle (Ct) values for SARS-CoV-2-positive specimens grouped by vaccination status. B) N1 Ct values for SARS-CoV-2-positive specimens confirmed to be delta variants by sequencing. In A and B, the horizontal dashed line represents the threshold for consistent recovery of infectious virus as well as our Ct cut-off for sequencing specimens. Sequence data were available only for specimens collected on or before 16 July 2021, not all samples had a Ct < 30, and not all samples with a Ct < 30 sequenced successfully, accounting for the relatively low number of delta confirmed sequences. P-values were calculated by comparing mean Ct values between groups by Welch two sample t-tests. Data from the Dane County cohort are shown.

Important observations

The respiratory samples used in this study to estimate viral load were collected during July 2021, when the delta variant was predominantly circulating worldwide and the number of new COVID-19 cases was increasing in the United States.

<img alt="Viral loads for the expanded Wisconsin cohort, including Dane County, are independent of vaccination status. A) N1 cycle threshold (Ct) values for SARS-CoV-2-positive specimens grouped by vaccination status. Specimens were collected from 11 Wisconsin counties. B) N1 Ct values for SARS-CoV-2-positive specimens were confirmed to be delta variants by sequencing. In A and B, the horizontal dashed line represents the threshold for consistent recovery of infectious virus as well as our Ct cut-off for sequencing specimens. Sequence data were available only for specimens collected on or before 16 July 2021, not all samples with a Ct < 30 were sequenced successfully, and not all were delta, accounting for the relatively low number of delta confirmed sequences. P-values were calculated by comparing mean Ct values between groups by Welch two-sample t-tests. Data from the expanded Wisconsin cohort, including Dane County, are shown." height="1071" src="https://d2jx2rerrg6sh3.cloudfront.net/image-handler/picture/2021/8/dd3331387v1.jpg" srcset="https://d2jx2rerrg6sh3.cloudfront.net/image-handler/ts/20210802115424/ri/2044/picture/2021/8/dd3331387v1.jpg 2044w, https://d2jx2rerrg6sh3.cloudfront.net/image-handler/ts/20210802115424/ri/1950/picture/2021/8/dd3331387v1.jpg 1950w, https://d2jx2rerrg6sh3.cloudfront.net/image-handler/ts/20210802115424/ri/1750/picture/2021/8/dd3331387v1.jpg 1750w, https://d2jx2rerrg6sh3.cloudfront.net/image-handler/ts/20210802115424/ri/1550/picture/2021/8/dd3331387v1.jpg 1550w, https://d2jx2rerrg6sh3.cloudfront.net/image-handler/ts/20210802115424/ri/1350/picture/2021/8/dd3331387v1.jpg 1350w, https://d2jx2rerrg6sh3.cloudfront.net/image-handler/ts/20210802115424/ri/1150/picture/2021/8/dd3331387v1.jpg 1150w, https://d2jx2rerrg6sh3.cloudfront.net/image-handler/ts/20210802115424/ri/950/picture/2021/8/dd3331387v1.jpg 950w, https://d2jx2rerrg6sh3.cloudfront.net/image-handler/ts/20210802115424/ri/750/picture/2021/8/dd3331387v1.jpg 750w, https://d2jx2rerrg6sh3.cloudfront.net/image-handler/ts/20210802115424/ri/550/picture/2021/8/dd3331387v1.jpg 550w, https://d2jx2rerrg6sh3.cloudfront.net/image-handler/ts/20210802115424/ri/450/picture/2021/8/dd3331387v1.jpg 450w" sizes="(min-width: 1200px) 673px, (min-width: 1090px) 667px, (min-width: 992px) calc(66.6vw – 60px), (min-width: 480px) calc(100vw – 40px), calc(100vw – 30px)" title="Viral loads for the expanded Wisconsin cohort, including Dane County, are independent of vaccination status. A) N1 cycle threshold (Ct) values for SARS-CoV-2-positive specimens grouped by vaccination status. Specimens were collected from 11 Wisconsin counties. B) N1 Ct values for SARS-CoV-2-positive specimens were confirmed to be delta variants by sequencing. In A and B, the horizontal dashed line represents the threshold for consistent recovery of infectious virus as well as our Ct cut-off for sequencing specimens. Sequence data were available only for specimens collected on or before 16 July 2021, not all samples with a Ct

Viral loads for the expanded Wisconsin cohort, including Dane County, are independent of vaccination status. A) N1 cycle threshold (Ct) values for SARS-CoV-2-positive specimens grouped by vaccination status. Specimens were collected from 11 Wisconsin counties. B) N1 Ct values for SARS-CoV-2-positive specimens were confirmed to be delta variants by sequencing. In A and B, the horizontal dashed line represents the threshold for consistent recovery of infectious virus as well as our Ct cut-off for sequencing specimens. Sequence data were available only for specimens collected on or before 16 July 2021, not all samples with a Ct < 30 were sequenced successfully, and not all were delta, accounting for the relatively low number of delta confirmed sequences. P-values were calculated by comparing mean Ct values between groups by Welch two-sample t-tests. Data from the expanded Wisconsin cohort, including Dane County, are shown.

Based on the Ct values, no significant difference in viral load was observed between fully vaccinated and unvaccinated individuals. Of all collected samples, 16 were sequenced to identify viral variants. The delta variant was identified in the majority (88%) of sequenced samples, indicating a high prevalence of this variant in Dane county.

For further analysis, additional 208 samples from other Wisconsin counties were included. Of a total of 291 samples from all counties, 73 were associated with vaccine breakthrough cases. About 84% of vaccine breakthrough cases exhibited Ct values less than 30, which indicates the presence of infectious virus in respiratory samples. Similar Ct values were estimated in 83% of unvaccinated individuals with SARS-CoV-2 infection. Surprisingly, about 33% of vaccine breakthrough cases exhibited very high viral loads with Ct values less than 20.

Based on the genetic sequencing data, the delta variant was identified in 84% of all tested samples. This further indicates a high prevalence of the delta variant in Wisconsin during the study period. Based on this information, the scientists assumed that the delta variant caused almost all infections considered in the study.     

Study significance

Taken together, the study findings indicate that the delta variant of SARS-CoV-2 is capable of inducing infection even in fully vaccinated individuals and that a significant proportion of vaccinated individuals with breakthrough infections are capable of transmitting the virus to others.

In Dane county, almost 68% of the population is fully vaccinated. Unfortunately, despite high vaccine coverage, a high percentage of vaccine breakthrough infections with high viral loads have been detected in this county. This finding further highlights the need for frequent testing and continuous adherence to non-pharmacological control measures to limit the community-level spread of SARS-CoV-2.

*Important Notice

medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information

Journal reference:

Source of this news: https://www.news-medical.net/news/20210803/Unvaccinated-and-vaccinated-have-similar-viral-load-in-communities-high-in-SARS-CoV-2-delta.aspx

Related posts:

Apple Putting a Stop to Email Tracking Pixels With Mail Privacy Protection in iOS 15 and macOS Monte...
Tracking when you've opened up an email and what you've read is something that many companies and advertisers rely on for their marketing efforts, plus there are email clients out there designed to l...
Best VPN services to use in Thailand - The Thaiger
Due to a series of laws that censor websites and increase surveillance powers for local authorities, internet freedom has changed dramatically in Thailand. Over 100,000 websites are blocked in the co...
Fix Netflix Error NSEZ-40 properly once and for all - TheWindowsClub
Netflix Error NSEZ-403 occurs on Windows 11/10 when you try to play a video. In fact, as per users, the error message appears mainly when trying to play specific videos. Continue with the troubleshoo...
Lincoln Star Concept: Could a sport tourer be in Lincoln's electric future? - Yahoo Entertainment
Lincoln unveiled Wednesday at an event in Hollywood its first fully electric concept vehicle: The Lincoln Star Concept, a crossover that looks a lot like a Corsair or Nautilus crossover with a longer...
Are usually Purpose of a Proxy Computer? - Digital Information Sector
If you ever went the net using a corporate or a study PC, you've probably used the proxy server. Their prime objective is to serve as any kind of buffer between your device and the rest of the models...
Form DEF 14A Enact Holdings, Inc. For: May 12 - StreetInsider.com
Get inside Wall Street with StreetInsider Premium. Claim your 1-week free trial here. SCHEDULE 14AProxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No...
TheSocialProxy Review: Taking Social Media Management to the Next Level - Make Tech Easier
As a social media marketer, or simply a person who manages multiple social media accounts, you may benefit from using a proxy service. Most social networks don’t allow multiple accounts, so the...
Rotating Proxies for Scraping - London Post
The truth is, most websites have a limit to the number of requests sent from the same IP address within a given time frame. Exceeding the rate limit will get your address blocked, and the connection...
Tools Of The (Ad Fraud) Trade - Forbes
Over the years, many ad fraud deniers have come out of the woodwork to attack my research and me personally. They say I’m deliberately overblowing ad fraud for personal gain, and that ad fraud is low...
Studio Network Solutions Improves EVO Suite With Apple-Certified ProRes Transcoding, More Upgrades -...
Story Highlights The Slingshot automations engine and ShareBrowser media asset management system—both included with EVO media servers — have been updated with incredible new features for creative tea...
Relaxed initiation pausing of ribosomes drives oncogenic translation - Science Advances
INTRODUCTIONDysregulation of mRNA translation is a frequent feature of cancer cells (1–3). Many oncogenic signaling pathways (e.g., RAS, phosphatidylinositol 3-kinase/mechanistic target of rapamycin ...
How to use a VPN on PS4 or PS5 - The Loadout
As gaming consoles become more advanced, we find ourselves using them for more things beyond simple gaming. With built-in browsers and apps allowing us to do most things that we might also do on a ga...
The safety Implications of Application Progress | eWEEK - eWeek
Particulars Point No . 4: Associations don’t feel confident of the security. A little less than part of surveyed organizations said these are definately very or extremely proficient about the...
Macdonalds Developing "SiliFuzz" For Fuzzing CPUs To Uncover Electrical Blemishes - Phoronix
By having OSS-Fuzz for continuous fuzzing of open-source projects and after that along with working on the various sanitizers for compilers, Google has been doing a lot for proactively unveiling s...
What is iCloud Private Relay? - TrustedReviews
Apple’s iCloud Private Relay is a service available to iCloud+ subscribers who use iOS 15, iPadOS 15 and macOS Monterey. It makes your web browsing and online activities more private by concealing yo...
Mandiant finds threat actor focusing on email collection over very long stretches - iTWire
Security nice Mandiant has released details about a particular threat actor it has referred to as UNC3524, which infiltrates and furthermore resides for long periods located in Windows environments...
Are there Most Secure Methods Of Storing Bitcoin? - News Chant MARKET
Nevertheless in 2020 and 2021, the price of cryptocurrencies such as Bitcoin has increased significantly, exceeding it really is previous all-time highs. Often the victims stand by and watch because...
10 Techno-Cool Cars - IEEE Spectrum
The auto industry is quick to entertain new ideas but slower to implement them. Although Robert Bosch perfected diesel fuel injection in the 1920s, it was decades before the technology made it into t...

IP Rotating Proxy Onsale

SPECIAL LIMITED TIME OFFER

00
Months
00
Days
00
Hours
00
Minutes
00
Seconds
First month free with coupon code FREE30