NEWS RELEASE November 2020
Herd Immunity with a Combination of Vaccines and CATE Masks
Future cases of COVID can be determined by the reproduction number (RO pronounced “R naught”) In the case of measles in an unvaccinated population it is a high as 18. Each infected person infects 18 others. Herd immunity occurs when the RO is below 1 as is the case when most people are vaccinated. Presently the RO for COVID in some countries is as high as 3. The calculation is that when herd immunity reaches 70% the disease will start disappearing.
There are a number of variables relative to immunity through vaccines including the efficiency and length of protection. Given the recent announcements relative to vaccines we can guesstimate that 20% of the world population could be vaccinated by July 1. Over the following year the percentage could increase to 65%.
Mask use can compensate for the lack of vaccine with maximum deployment in the next six months and then steady reduction over the next 20 months. Many people will refuse to take the vaccine. In poorer countries it is unlikely that the 65% vaccination level can be obtained in the next two years.
It is important to understand the big differences between masks.
CATE is an acronym for Comfortable, Attractive, Tight Fitting, Efficient. These masks have been available for many years to combat air pollution, wildfires and pollen. They are the ideal selection for the general public in the fight against COVID. This is not true of other mask types. Here are the numbers.
In a room where people are social distancing at six feet and MERV 8 filters are used in an HVAC system with three air changes per hour unmasked individuals will be generating a cloud of virus particles similar to perfume or cigarette smoke. If masks are worn by transmitters as well as recipients, the net protection is a combination of the performance of both masks.
The net effectiveness is a function of the potential capability of the mask minus failure to achieve a tight fit and periods where the mask is discarded due to discomfort or social drivers. When all is considered the CATE mask combination is 93% effective compared to only 49% for the cloth mask.
Mask type: CATE masks are generally reusable and have various features to make them attractive, tight fitting and comfortable as well as efficient. Surgical masks are efficient but not tight fitting. N95 masks can be fitted for a tight seal but when worn by general public they are often not used properly. Cloth masks can excel in comfort and attractiveness but are loose fitting and inefficient.
Direct Leakage: This is the amount of air which is exhaled around the mask directly.
Re-entrainment: Droplets initially captured on masks evaporate and split causing virus to escape.
Penetration: This relates to the efficiency of the filter media.
Use Discount: Masks should be worn as appropriate. Cloth and CATE masks are more comfortable than the others and are more likely to be used in borderline situations.
Recipient Load: This is the virus escaping the transmitter mask.
In Leakage: This is the amount inhaled around the mask seals.
There is no question that tight fitting efficient masks are the most effective weapon against COVID. These masks prevented any U.S. medical staff fighting Ebola to become infected. The COVID incidence among medical personnel in high COVID environments is very low. In cases where these personnel had no choice but loose fitting surgical masks the infection rate was high. If a comfortable, attractive version is available to the general public the battle can be easily won.
So combining CATE masks and vaccines is a winning combination. CATE masks have a 7% inefficiency factor. So when 20% are vaccinated you need 57% wearing masks to reach the 70% herd immunity. If 6 billion of the 8 billion people in the world need to be masked or vaccinated then 3.4 billion people will need masks through July of next year. This number decreases over the next 12 months to just 720 million people. (These estimated do not take into account the people who are immune because they were infected. Nor those who take the vaccine but are not immune. These may not be entirely offsetting.)
Because CATE masks are reusable it is not an insurmountable challenge to supply masks for billions of people. Longer term the market could fall to 720 million people wearing three masks per year at $30 per mask or $64.8 billion. This does not include masks needed for air pollution, pollen, and wildfire protection.
The technical analyses of masks and filters are found in Coronavirus Technology Solutions Click here for more information