The long answer of why that good news may be true follows:
BCG is a Tuberculosis (TB) vaccine that is made from deactivated (dead) bovine TB cells. It is administered via skin prick in low income, high population, and poor health countries such as India. This skin prick is just like the old Smallpox vaccines many of us got in our shoulder as children here in the USA. The effectiveness of BCG against TB is for adults and is widely variable, based on which strain is used, but consistently low (Zero percent in southern India). Again this is for ADULTS. For small children it is much more effective against TB, but the effect generally disappears during adolescence. As for BCG helping with other infectious diseases, there is some good data to support effectiveness against Leprosy, but not really for anything else. Keep in mind that both TB and Leprosy are caused by bacteria, which we also call "germs" or "cooties" and are living organisms like the amoebas and parameciums we saw under the microscope in grade school. TB and Leprosy belong to a specific subset of bacteria called mycobacteria, which means they are slow-growing, Gram-positive, catalase positive, non-motile, non-spore forming, rod-shaped bacteria (0.2–0.6 μm wide and 1.0–10 μm long).
Being bacteria is an important distinction from the Wuhan Virus, aka Corona Virus or now officially the SARS-CoV-2 Virus which causes the disease called COVID-19. A virus is an entirely different animal from a bacterium, and technically not an "animal" at all. A bacterium is a single-celled living organism that can survive and reproduce on its own, while a virus is not technically "alive" at all. Viruses are simply a single piece of genetic material (DNA or RNA) inside a protein shell called a capsid. They cannot stay active or reproduce without a host cell. Viruses propagate and "survive" by hijacking host cells and using them to make new viral proteins. Viruses are pure evil - almost all of them cause disease, while most bacteria are beneficial for health or ecosystems with less than 1% causing disease. Many bacteria can be killed with antibiotics, which do nothing at all to viruses.
Both viruses and bacteria can be controlled with vaccines, which operate quite differently from antibiotics or other drugs. But the vaccines tend to be very specific to each disease. In short they introduce something to your body that is similar to the actual disease virus, but (hopefully) different enough to not cause the disease, or cause illness less severe than the targeted disease. This is why some people get sick after getting flu shots, for instance, the assumption being that that illness is less severe than actual influenza. The vaccines do not attack the disease directly. How could they, since they are almost universally administered to people who don't have the disease in the first place? Instead the body reacts to the vaccine, identifying it as something bad, and marshaling your natural defenses to stop it. Contrary to popular opinion, all the detailed natural responses your body has to disease or toxins are not known or fully understood. But we do have an idea that vaccines help your body to identify them as bad actors, and your immune system develops "antibodies" that effectively stop them. The designs of those specific antibodies go into your immune system's "memory database," so that if the real disease shows up, they system determines it has seen these before, then it dials up, generates, and deploys the appropriate antibodies to stop the real disease.
What the mainstream media are reporting, and it all seems to be repeats of a single story that they are all parroting almost verbatim, is that maybe this 100 year old vaccine may be the magic cure to stop the SARS-CoV-2 virus. The data show very broad based statistics from national health organizations from lesser developed countries that use BCG skin prick vaccines, mostly at birth, and all of that data comes with suspect reliability and consistency. Laying that iffy data against data from the World Health Organization (WHO) compares rates of infection and rates of BCG vaccination. These very unreliable data show a POTENTIAL correlation between high BCG vaccine rates and low infection rates. These data come from disparate sources of wildly variable reliability, and most from areas with low GDP and very low levels of testing, so even the statistical inference of correlation can only spawn new testing of the correlation using controlled data collection. Unsurprisingly, several of those new studies have been initiated.
And we all KNOW (but often forget) that correlation and causation are different and not necessarily linked. For instance there is a very high statistical correlation between people that have committed murders and consumption of ground beef in the previous 72 hours. Does this mean that vegetarians are all peaceful and hamburger-eaters are all poised to kill? Of course not! So there is a lot of work to be done to see if BCG can be used or modified to fight SARS-CoV2. And keep in mind that the BCG treatments for bladder cancer are NOT the same as these vaccinations.
A reasonably neutral summary of what has been reported and what it really means can be found in this YouTube video:
By now you are wondering, where is the good news? There actually is some. As Bladder Cancer survivors, most of us have received 3 or more BCG treatments, but almost NONE of us have had BCG vaccines via skin prick. Our Bladder Cancer BCG treatments are NOT vaccines, but are Immunotherapy treatments. As I have discussed in previous blogs, there is no agreement about how Bladder Cancer propagates - some believe the bladder is defective and genetically will produce or allow production of cancerous cells, while others (like me) believe the cancer forms from external stimuli (diet, toxins in the environment, etc.) and propagates by "seeding" from the original site. Therefore, because there is no agreement on how Bladder Cancer actually works, there is no full understanding about how BCG might really work. But all immunotherapies work somewhat like vaccines. In our case the BCG tricks your body into thinking something is VERY wrong with your bladder, and therefore stimulates your immune system to send in "all the troops" (which are not fully understood) to fight the supposed infection. This is why we get "flu-like" symptoms after BCG treatments.
Based on your point of view about Bladder Cancer, you either think the immunotherapy OVER TIME "trains" your bladder to stop making cancer cells, or "trains" your immune system to stop allowing Bladder Cancer seeds to propagate into tumors. How it happens is, of course, less important than the fact that SOMETHING does happen and the correlation and causation have been proved over time to be statistically significant.
So what does that mean for us? Since our immune systems have been tricked into responding with antibodies (and T cells, and NK "killer" cells, and various types of white blood cells, and other both known and unknown things) to react to BCG's trickery, it is certainly possible that our immune systems are in general stronger than before, with quicker and more specific reactions, and therefore more effective than the average person's. I can personally share with you that I have had only 4-5 colds in the past 10+ years, and only one was severe enough to require bedrest (and only lasted 2-3 days). And nothing else. In general I cannot tell the difference between catching a cold and having a couple of bad allergy days. So it seems to me that my immune system's reaction time and effectiveness is on hyperdrive. Which is cool, and potentially life-saving these days.
The benefit that most of us will receive from our BCG immunotherapy treatments is something called "non-specific immune-boosting effects," which is a science-y way to say that our immune systems are complex and not fully understood, and many of the things "learned" by immune systems are able to fight things other than the ones originally targeted. This is the good news - the tiredness, general malaise, and other flu-like symptoms produced by BCG immunotherapy will not only help our bodies to fight bladder cancer, but also to fight other things.
A final few words on just how bad this pandemic might be:
This is my rational and data-based take on the current pandemic faced globally with SARS-CoV-2 and COVID19. What has been reported so far is statistically over-biased towards higher than actual mortality rates. This bias happens because the people who are being tested for the disease is a MUCH smaller number than those who actually have (or had) COVID19. This low level of testing is both reasonable and necessary because of the limited number of test kits. Those being tested are those with the strongest reactions, worst symptoms, many of whom may otherwise be in the higher risk groups. SARS stands for Severe Acute Respiratory Syndrome, and anyone with any type of lung impairment (even mild asthma) is more at risk than an average person. What that boils down to is that the high fatality rates (widely reported at over 5% and even as high as 20%) are primarily a mathematical function of the denominator of the fraction being understated. It works like this:
Mortality rate = Number of deaths (for any reason) of COVID19 infected persons
Number of confirmed cases (by testing)
Simple math tells us that this fraction will be a lower number when the bottom number (denominator) is higher than the top number (numerator). If a lot of people that have COVID-19 are not tested due to a lack of test kits, they are not counted and the bottom number (denominator) is smaller than it should be. Most honest news sources have calmed down a bit and are reporting mortality rates at around 2%. This is still hugely bad - with regular influenza's mortality rate being well known at 0.1% (a tenth of a percent), that means COVID-19 is about 20 times worse as far as risk of dying.
Here's the problem - that 2% is probably grossly overstated, by a LOT. I have a real-life example, first person, directly from a someone I know and reported to me, whose entire office was exposed and infected This is first hand information, from the source, not secondhand from "a guy my cousin knows" or whatever. His office has only 26 people, so it is not statistically significant in any way, but it can be indicative of how even the 2% mortality rate should be viewed with some realistic skepticism.
Of the total population of that office, only 1 person was tested (5%). That person was admitted to the hospital for 2 days for observation and represents ONE confirmed case in the statistics. Nobody else in the office was tested, and therefore were NOT confirmed cases. Instead they were told, after an analysis of their work space, habits, and proximity, that there was a nearly 100% chance they were exposed and almost equally high chance they were infected. And they should ALL assume they WERE infected and simply go home for and self quarantine for 14 days, and otherwise do nothing unless their symptoms required a trip to the Emergency Room.
Using slightly rounded numbers, of that office population (100%)
- 95-100% actually infected (this 5% range presumes one person might have been exposed and not infected, which is quite unlikely)
- 15% had significant symptoms (3.5 days chest pain/cough + 3.5 days difficulty breathing)
- 55% had mild symptoms (4-5 days extreme fatigue - hard to stay awake all day)
- 25-30% had NO SYMPTOMS at all (this 5% range presumes one person might have been exposed and not infected, which is quite unlikely)
- 0% mortality in this small (not statistically significant) sample
Here's the thing - BEFORE they were aware by testing that they had been exposed, it has been estimated that they unknowingly exposed an ADDITIONAL 91 persons, an unknown number of which may have been tested or died. Here's where the math gets interesting. For only ONE confirmed and tested case, there were another 24-25 definite cases which are NOT reported in the stats as confirmed (by testing), plus up to ANOTHER 90+ probable cases, an unknown number of which ever became "confirmed." This puts the margin of error at somewhere between 20 times and 110 times as many actual COVID-19 cases versus the number reported as confirmed (and tested).
If we go VERY conservative, and suggest that it's only 10 times as many (rather than 25-110 times), that puts the mortality rate at 0.2% or twice as bad as regular flu. I am NOT trying to trivialize this, because the SARS-CoV-2 virus is stronger and therefore more survivable outside the host than regular flu - meaning you can get infected from a metal surface, for example, up to 2 days after it's contaminated. COVID-19 is therefore MUCH more contagious and infectious, and certainly MUCH more perilous to anyone with compromised lung function. So the numbers of deaths could certainly get much higher than regular flu, simply because a lot more people will likely get COVID-19 than would ever get regular flu, and the mortality rate is perhaps twice as high as regular flu (though likely less than that).
What I am trying to do is offer encouragement to those who have received BCG (or any other) immunotherapy treatments. Your chances of being in the 85% with mild symptoms or no symptoms may well be larger than 85% simply because your immune response is faster and more effective than average. And that is pretty good news indeed.