A candy made of caramel and dehydrated S. cerevisie (the yeast used for making bread or beer) that allows easy and early detection of COVID-19
One of the main problems with coronavirus is the development of quick tests that can be performed at home. Even if quick tests have been developed
they either require the use of nasopharingeal swabs to increase viral load for detection, or in case of blood test, they test for antibodies rather than the
virus itself, so detection is variable and only happens once the inmune system is starting to response.
How it is used
1. People eat Sweet-Cov2
2. Thanks to the water and temperature of our mouth together with the sugar in the candy, yeast is activated and detects COVID-19
3. In response to COVID-19 detection, yeast produces quorum sensing molecules, which are alcohols
4. Person breathes in a breathalyzer either at home, or before entering a supermarket, going to the airport etc.
How does Sweet-Cov2 detects low viral loads?
1. Since it is a candy, this will ensure we will have it in our mouth for a long period of time, increasing sensitivity even with low viral loads
2. Since the COVID-19 detection activates quorum sensing pathway, not all yeast cells need to detect COVID-19 in order to produce the quorum sensing alcohols,
and therefore signal is amplified before measurement
Technical Design
1. We use yeast since COVID binds to the human protein ACE2 and therefore we need to use an eukaryotic system if we want to be able to detect it
2. We will design a gene circuit with ACE2 under a constitutive promoter so that S. cerevisie binds COVID-19 when present
3. We will include another gene that mediates the response to ACE2 activation but that will be linked to the quorum sensing response genes that S. cerevisiae already has in its genome
3. S. cerevisie produces aromatic alcohols as quorum sensing response: 2-phenylethanol, tryptophol
4. Production of these quorum sensing alcohols will increase yeast response, amplifying the signal detection for COVID-19
5. Then the person will just need to breath in a breathalyzer similar to those use for alcohol tests, detecting the presence of COVID-19
Steps for accelerated approval by the US FDA
Under the current situation, the approval will be much easier since the FDA approved Emergency Use Authorization (EUA) of in vitro diagnostics for COVID-19
1. As a diagnostic device, we will need to prove efficiency, calculating the Limit of Detection (LoD), inclusivity (100% detection of all SARS-Cov2 strains) and cross-reactivity (analytical specificity)
2. The FDA has published a “Test Kit Manufacturer: EUA Template”, that can be completed and sent for approval
3. Review and approval is granted on a rolling basis so although times are not specified, I believe it should be pretty quick.
Steps for regular approval of a vaccine by the US FDA
In case of a non-urgent vaccine approval, the process could take up to several years (8-10) since it would have to follow the same regulatory pathway as with any drug.
1. Pre-clinical trials, including in vitro and animal studies that define the ADME/PK, toxicity, efficacy and safety of the vaccine in animals.
2. Submission of IND (Investigational New Drug Development before clinical trials in humans are allowed
3. Phase I clinical trials: very few individuals. We study safety
4. Phase II clinical trials: enroll some hundreds of patients and study dose-ranging in different individuals to understand toxicities.
5. Phase III clinical trials: thousands of individuals, to study efficacy
6. Submission of Biologics License Application (BLA)
7. After that, the review by the VRBPAC is done by a committe of non-FDA members and manufacturers have to be approved too