Methods for Mitigation

Overview

The effort to get the pandemic under control has given rise to a host of remedies. Quarantines and social distancing guidelines have been the defacto first line of defense along with rigorous personal hygenics and use of surface disinfectants. Vaccines have the headlines and funding for accelerated development. Isolation can be effective but was not implemented fast enough to contain it and has been compromised by uneven compliance under the stress of a sustained lockdown. Vaccines, while raising hope, have yet to complete testing and approval for the general population.

The prolonged hardship makes a case for additional measures of mitigation in advance of a vaccine. The existing methods were reviewed along with a few relevant technologies for improved availability and effectiveness should we face this crisis again. It’s only a matter of time.

Isolation

The most effective way to keep humans from spreading the diesase is to limit H2H (human-human) contact.

Quarantine - Isolates carriers of the disease from the rest of the population until they are no longer contagious. Authorities have closed borders and imposed 14 day quarantines for travelers from infected regions. It works.

Social Distancing - The recommended separation of 6 ft/2m has been actively promoted with some benefit. However, the growing awareness of airborne transmission in aerosol form greatly exceeds this distance and is likely to increase the mandate for additional measures. It still helps.

PPE - Masks and other forms of PPE (personel protective equipment) help reduce the risk of infection with compliance by a majority of a population. And very recently, the use of masks seems to have some beneficial association with asymptotic carriers, perhaps responsbile for a minimal exposure level sufficient to trigger the immune response without overwhelming the system. It most definitely helps.

Contact Tracking - A form of this was rolled out in Wuhan not long after the original outbreak and is being credited with reducing further impact. Singapore made good use of this to track infection patterns for a specific incident and strengthen the case for compliance. Google and Apple have offered this option on cell phones in the US but effectiveness has been hampered by lack of response. For example, more than a third of the calls to people who tested positive over the course of a week in Los Angeles County went unanswered. More than half of those who did pick up refused to provide one close contact. Compliance is most likely higher in other countries.

Immunization

Vaccines are proven to be effective against a range of diseases, In all cases they trigger the immune system to create antibodies to fight a specific virus.

Herd Immunity - The “natural” progression of a disease. If enough people develop immunity through exposure or vaccination, the transmission of the disease is reduced or eliminated. It takes anywhere from 60-90% of the population to be infected to achieve this. In the absence of a vaccine, the number of deaths to achieve this state could become “unthinkable”.

Virus - Utilizes a weakened or inactivated version of the target virus to build immunity. This was the original method used to erdicate smallpox.

Viral Vector - Uses a non-lethal virus as a carrier for the payload. Replicating versions can be safe while triggering a strong immune response but only work with limited percentage of a population. Non-replicating versions have considerable usage in gene therapy but none have ever been licensed as a vaccine.

Nucleic Acids - Uses cell DNA/RNA as the trigger. mRNA based vaccines have the potential to be quickly manufactured in volume but must ovecome challenges with practical deployment. It’s worth noting no nucleic acid vaccine has ever been approved by the FDA.

Protein based - Injects bits of virus-related protein to activate an immune response. It is considered harder to make and can require adjuvants and multiple doses to be effective.

Inactivation

There is some comfort in an active response to the virus. The following methods act directly on the virus.

Chemicals - The focus for initial guidelines was localized hygenics (i.e. rigorous hand-washing) and surface disinfectants which deactivate the virus by oxidizing or otherwise breaking down the protective lipid coating of the virus. Active ingredients for disinfectants include;

Ethanol, alcohol-based products disintegrate the protective lipids.
Bleach and other potent oxidizers swiftly break down a virus’s essential components.
Quaternary ammonium commonly used in health-care and food-service industries, attack protein and lipid structures

The growing awareness and significance of airborne viruses in aerosol form as the main mode of transmission has raised the profile for a few alternatives given their potential to address the These methods are generally “indirect” in that human safety issues

UVC - UVC has been used in germicidal applications for 35 years to disinfect water, tools, surgical surfaces and more recently the general reduction of infections in hospitals. A wavelength of 254nm generated by high powered xenon or lamps.

The primary mechanism is to damage the RNA to prevent it from replicating using

The wavelength, power and ozone levels generated in operation are too high for human exposure which makes this approach only suitable for indirect applications.

FarUVC - covers the region of 207 -222nm. Preliminary testing has demonstrated meaningful inactivation in a matter of minutes. These wavelengths are too chort to penetrate deep enough to damage human cells without losing the ability to inactivate the virus which makes it a candidate for direct exposure deployments.

SRET - ( see ”SRET - Assessment & Summary”, BauNovus, 2020 )

Other - Include possibilties such as non-thermal plasma, et al could provide some alternative to the existing methods being considered.

Remedies

Testing - A significant factor in managing the scope and velocity of the spread, facing challenges to test sufficient numbers to be effective.

Active air filtering systems might help in confined quarters but with limited practical effectiveness.

Drugs such as Remdesiver, Synairgen, etc. have made headlines but are intended to relieve symptoms and lower the risk of death for hospitalized patients .

Hydroxychloroquine remains controversial and unproven as to confirmed benefit.

Summary

The well known methods have delivered some degree of relief, but all fall short of 100% wrt to either effectiveness, compliance or availability. It is unclear whether any one will be sufficient to end this quickly. It is clear that additional measures coiuld be helpful.

Isolation works with compelling evidence in the cases of compliance (NZ, DE, etc.) vs. non-compliance (US, SE, etc). The prolonged duration of the pandemic is likely to test the general publics ability to maintain the discipline required to achieve the desired results.
Vaccines take years to develop. The headlines have made a big deal of the accelerated efforts, but the existing record for a vaccine to market is four years (mumps). There will be concern over the potential for unforseen side effects. As of 12 Aug, the US govt has pre-emptively funded the manufacture and stockpiling of several promising vaccines in advance of successful completion of Phase III trials ($9B). A successful candidate could be available for distribution by early 2021.
No vaccine is 100% effective. Metadata analysis for the flu vaccine shows effectiveness for only 67% of the population.
Even when a vaccine becomes available, the durability remains an unknown. Effectiveness for the influenza vaccine drops from 35% ?!! after a few months to 0% in 150 days, which is why booster shots are promoted at the beginning of every flu season.
An additional challenge is the suspicion and rejection of vaccines based on indiviual beliefs that could defy innoculation for as much as 1/3 of the population in the US.
UVC has potential for it’s known germicidal capabilities and is starring in security theater for airlines but remains a secondary measure in terms of deployment. “FarUVC” has potential for a greater range of applications with the same degree of effectiveness and reduced concern with human exposure.
Efficacy vs. Effectiveness. The inactivation methods have demonstrated some degree of -efficacy- in research settings and limited installations, but -effectiveness- in practical applications remains to be determined.

A microwave based technology was explored in more detail and compared with the other methods to explore the potential to add to the toolbox. See Comparison of Methods for further detail.

THE PROJECT