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Review of "Colorimetric Test for Fast Detection of SARS-CoV-2 in Nasal and Throat Swabs"

Reviewer: Chayan Kanti Nandi (Indian Institute of Technology Mandi) | 📒📒📒 ◻️◻️

Published onMay 07, 2022
Review of "Colorimetric Test for Fast Detection of SARS-CoV-2 in Nasal and Throat Swabs"
key-enterThis Pub is a Review of
Colorimetric Test for Fast Detection of SARS-CoV-2 in Nasal and Throat Swabs
Description

AbstractMass testing is fundamental to face the pandemic caused by the coronavirus SARS-CoV-2 discovered at the end of 2019. To this aim, it is necessary to establish reliable, fast and cheap tools to detect viral particles in biological material so to identify the people capable to spread the infection. We demonstrate that a colorimetric biosensor based on gold nanoparticle (AuNP) interaction induced by SARS-CoV-2 lends itself as an outstanding tool for detecting viral particles in nasal and throat swabs. The extinction spectrum of a colloidal solution of multiple viral-target gold nanoparticles – AuNPs functionalized with antibodies targeting three surface proteins of SARS-CoV-2 (spike, envelope and membrane) – is redshifted in few minutes when mixed to a solution containing the viral particle. The optical density of the mixed solution measured at 560 nm was compared to the threshold cycle (Ct) of a Real Time-PCR (gold standard for detecting the presence of viruses) finding that the colorimetric method is able to detect very low viral load with a detection limit approaching that of RT-PCR. Since the method is sensitive to the infecting viral particle rather than to its RNA, the achievements reported here open new perspective not only in the context of the current and possible future pandemics, but also in microbiology as the biosensor proves itself to be a powerful though simple tool for measuring the viral particle concentration.

To read the original manuscript, click the link above.

Reviewer 1 (Chayan Kanti Nandi) | 📒📒📒 ◻️◻️

RR:C19 Strength of Evidence Scale Key

📕 ◻️◻️◻️◻️ = Misleading

📙📙 ◻️◻️◻️ = Not Informative

📒📒📒 ◻️◻️ = Potentially Informative

📗📗📗📗◻️ = Reliable

📘📘📘📘📘 = Strong

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Comments
1
Vape Factory:

Unauthorized Breeze and Esco Bar Disposables: FDA Issues Warning Letters

In recent news, the FDA Center for Tobacco Products (CTP) has taken a strong stance by issuing warning letters to the manufacturers of Breeze and Esco Bar disposable vapes. These letters order the companies to remove their products from the market, giving them a window of 15 business days to either dispute the allegations or respond accordingly.

The FDA's actions come on the heels of significant developments in the industry. Just last week, six Chinese exporters of Esco Bar products, including the manufacturer Innokin, found themselves added to the FDA's "red list." This list identifies shippers whose Esco Bar shipments can be detained at ports of entry without inspection. Furthermore, Elf Bar shipments were also included in the import alert, signifying the increased scrutiny on disposable vapes.

These recent enforcement actions are part of a broader wave of initiatives promised by CTP Director Brian King during his recent speeches and discussions. The FDA is facing mounting pressure from lawmakers, tobacco control groups, and even tobacco companies like R.J. Reynolds to crack down on flavored disposable vapes that have gained immense popularity over the past couple of years.

Director King, in a press release, stated that the FDA will utilize all available tools within their regulatory toolbox to ensure that those involved in the production, distribution, or sale of illegal e-cigarette products are held accountable. Firms that receive warning letters have 15 days to respond, outlining how they plan to address the violation. Failure to adequately address the violation may result in various enforcement actions being taken against them.

The warning letters issued to Breeze Smoke, LLC and Shenzhen Innokin Technology Co., Ltd., rightly highlight that the products mentioned have not received authorization for sales in the United States from the FDA. However, it is worth noting that thousands of other products with premarket tobacco applications (PMTAs) pending before the agency continue to remain on the market.

At present, all unauthorized products exist on the market due to the FDA's enforcement discretion. This includes both the aforementioned products and those produced by mass-market vape manufacturers like JUUL and Vuse Alto. Interestingly, the FDA seems to have chosen to enforce against the products that R.J. Reynolds has specifically targeted, while leaving untouched their own popular product, the Vuse Alto.

These recent FDA actions may indicate a shift in the agency's approach. It is possible that pending PMTAs will no longer be considered when deciding which companies to enforce against.

Regarding Esco Bar, it is believed that they submitted pending PMTAs during a brief window in 2022 when the FDA accepted applications for synthetic nicotine-based vape products. Unlike the first round of PMTA submissions, where the FDA published a list of the submitted products, no public list of PMTAs submitted for "non-tobacco nicotine" (NTN) products has been issued.

On the other hand, Breeze Smoke faced marketing denial orders (MDOs) for several products in 2021. In response, the company swiftly filed a petition for review in the Sixth Circuit Court of Appeals. Despite being denied a stay pending appeal, Breeze Smoke sought a stay from the Supreme Court while awaiting a full review by the circuit court. However, the Supreme Court declined to grant a stay, leading Breeze Smoke to voluntarily withdraw its petition for review just two weeks before the scheduled oral arguments.

It's important to note that the Breeze products mentioned in the FDA's warning letter were not among the MDOs that Breeze Smoke previously contested in court. As for the current status of the products sold by Breeze Smoke, whether they have pending PMTAs with the FDA remains unknown.

Conclusion

The FDA's warning letters to the vape manufacturers of Breeze and Esco Bar disposables mark a significant step towards stricter regulation of the flavored disposable vape industry. With mounting pressure from various stakeholders, the FDA is taking action to ensure accountability and address the unauthorized sale of e-cigarette products. While the enforcement actions may signal a shift in the agency's approach, the impact on the market and pending PMTAs is yet to be fully determined.

FAQs (Frequently Asked Questions)

Q: Why did the FDA issue warning letters to the manufacturers of Breeze and Esco Bar disposables?
A: The FDA took action to address the unauthorized sale of e-cigarette products and hold the manufacturers accountable.

Q: What is the deadline given to the companies to respond to the FDA's warning letters?
A: The companies have 15 business days to dispute the allegations or respond to the warning letters.

Q: Are there other products on the market without FDA authorization?
A: Yes, there are thousands of products with pending premarket tobacco applications (PMTAs) before the agency.

Q: Will pending PMTAs be considered in future enforcement actions?
A: The recent FDA actions suggest that pending PMTAs may no longer be a determining factor in deciding which companies to enforce against.

Q: What is the status of Breeze Smoke's previous marketing denial orders (MDOs) in court?
A: The products referenced in the FDA's warning letter were not among the MDOs challenged by Breeze Smoke in court.