James Hamilton, M. D.
Apples and Oranges
This is more of my thoughts about the coronavirus which will dovetail on my comments in Post #6914. It is more of an "Op-Ed" but based on some known facts. Obviously, politics have gotten into the discussion of this disease but I want to concentrate on the medical/scientific aspects of it.
There have been a lot of comparisons mentioned in the press and on this Forum between COVID-19 and influenza infections. Some are valid. As I stated in #6914 personal, community, national (and international) hygienic and quarantine measures are important factors to help interrupt cycles of trainsmission for both. They are both viral infections of the respiratory system. However, outside of these I feel the comparison fades into the apple and oranges realm.
There have been decades of research into influenza viruses and the vaccines that can prevent them. The route which the flu viruses traverses through the USA is fairly consistent and goes from SW to NE in most years. This usually happens from the late fall into mid spring or so.The probability of which flu strains are going to occur is usually predictable and the vaccines are guided by those predictions. In most years the vaccines seem to be around 40-60% "effective". Even given that, the vaccines may still be proctective or, at least partially so (by attenuating the disease severity), in a multitude of individuals.
Past vaccine recipients may also have a greater protective effect when there is a current year "mismatch" since the viruses may share some properties with strains and the current vaccine may have an "anamnestic" effect on the host patient's immune system to develop a higer level of antibody response.
Another factor is that of "herd immunity" wherein more patients who get the vaccines and, therefore, may not become infected with the disease, cannot transfer the influenza infection to non-vaccinated persons.
Unlike influenza (which can be treated with things like Tamiflu and others) there are no drugs to offer patients in the early stages of COVID-19 infections.
COVID-19 has no vaccine currently. It is unknown whether it is a seasonal virus. It has not yet established a "natural" pathway for progression across the country since it is being spread mostly by the traveling public. We also don't know if infection and recovery results in immunity and there has not yet been been enough time for herd immunity to develop.
Why does COVID-19 appear to not affect children as severely as adults? My guess is that a child's lung cells may not yet have developed the needed "attachment" sites for the virus. But that is my own GUESS.
My opinion here is that comparisons between flu and COVID-19 are way to early to to have much validity. That includes death rates. Once we find a vaccine and/or antiviral medications that are effective, then we can make more appropropriate comparisons.
Jim
ADDENDUM:
Recently it has been found that COVID-19 can be shed in stools. This brings up the possibility of a fecal-oral transmission (sounds gross but it is mainly a breach in hand washing after toilet use type of prevention) and prompts me to wonder if that shedding continues for some time after resolution of the clinical respiratory disease or the quarantine time. After all, the source of the infection in China was believed to be in a market where food is sold and handled.
Indeed, there is much more that is needed to be learned about this virus.
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