devashish_paul wrote:
Can you help educate us on how some of this logic works and qualify it please with who you are and credentials (I am not questioning it, but its better if the statement is from a qualified identifiable person given all the misinformation that can flow around on internet message boards)
Question 1: If the vaccine is 90% effective, does this mean there is a 90% chance that I will not get Covid19. If I don't have it, I can't give it to someone else. There is a 10% chance I get it which means I can give it to someone else but the chance of giving it to someone else dropped by 90% compared to not vaccinated.
Question 2
Or is it 90% effective in ensuring that I don't get sick, but 0 percent chance of preventing me from getting it to some degree when I get exposed enough. So once I get it, how badly does it hammer me? But the vaccine itself is trying to minimize the impact on me, not shut the door for the virus on my body. If I get it I have 90% chance of not getting sick, but I still have it and can give to others?
Is this what you are getting at? I just assumed that those vaccinated will not give it to others just like those of us who got vaccinated from small pox could no longer give it to others since we would not get sick from it (but that was a totally different mechanism).
I have a Master's degree in public health, and I'm a current PhD candidate. Actually, I am
not an epidemiologist, which is the field that would deal directly with this (assuming they are infectious disease epidemiologists, anyway; note that not all of them specialize in infectious diseases). My bread and butter is clinical effectiveness, though, so I understand the basics.
In the randomized trials, the vaccine arm was around 90% less likely to get COVID than the placebo arm.
Here's one of the RCTs. I haven't gone deep into this one or others, but in this one, "to get COVID" means that you had COVID symptoms
and you got a positive PCR test (they stick a swab into your nose, then they stick that into a machine that replicates the virus' RNA or whatever it is, basically testing for an active infection). So, this is confirmed, symptomatic COVID.
So, to be really precise, it may be that you could still get asymptomatic COVID, not get any symptoms, but you still have enough of a viral load (amount of virus in, say, your nasal passages) to spread it. I don't have any clinical training, but I would assume that if you have the vaccine, your immune system responds much faster and more effectively to the virus. So, it stands to reason that your viral load would be lower if you got exposed to the virus. Maybe its near zero, and thus you are basically incapable of infecting anyone! But maybe not.
Basically, does the vaccine just block symptoms, or does it actually make you shed so little virus that you aren't infectious? We don't know this part. All we know is that compared to someone not vaccinated, you are 90% or more less likely to get symptomatic COVID.
Thus, out of an abundance of caution, once they vaccinate me, I intend to assume I could still get an asymptomatic but contagious infection. Naturally, I could also get symptomatic and infectious as well. I'm not going to live like a hermit for the rest of time, because nobody can. I would still urge people to be as cautious as they can sustain for the next year. We'll know more as time goes by, and we will certainly be able to lift the restrictions at some point. It's just that we have lost over 380,000 people here in the US.