Thread by @TimMalia

Please understand the COVID-19 vaccines do NOT envelope you in a bubble. The virus, if in the air about you, can still enter your nose.
#ThingsITellMyPatients
#ROC
1/24

The vaccines make your immune system able to fight the virus if it enters the body, not before that. Goal is to prevent severe disease & lessen spread.
2/24

If enough SARS-COV-2 virus enters one's nose (nasopharynx actually), it will settle into the tissue lining it, the mucosa.
3/24

The virus then starts getting into some of those superficial cells, making a huge number of itself, aka replicating.
4/24

At some point, the body's immune system notes the virus is foreign & triggers an immune response. Earlier if vaccinated, later if not.
5/24

The immune system then clears the virus. One may not note anything, or may note mild symptoms, like a cold.
6/24

By doing its job, the vaccine trained the immune system to prevent the virus from getting far into the body & causing a big systemic infection/response.
7/ 24

An immune response to a superficial mucosal infection is mild. But it's big, adding other risks even, when responding to a systemic infection.
8/24

There is a small chance the vaccine doesn't fully prime the immune system (round number 5% risk). In that case, one can still get a big COVID19 infection.
9/24

If enough of us get vaccinated with strong protection, the virus won't be able to spread around sufficiently to pose much community risk (herd immunity).
10/24

Even if vax effective, if virus enters the nose & there's enough viral replicating, a test for COVID19 might be positive before it's cleared.
11/24

Surveillance tests find many of those (pre-surgery, screening returning students, etc) even if one is not ill or only with mild symptoms.
12/24

Research continues on how many vaccinated folks might pass virus in that early stage, even if asymptomatic.
13/24

One may be infectious for a time before immune system clears virus if enough early replication. Delta replicates a lot so # of that variant can be high in the nose.
14/24

Thus the general recommendation of public masking for all, even the vaccinated, until more is known & infection/death rates are much lower.
15/24

Research continues but I imagine a prior infection may give an added line of protection. Since virus entered one's nasopharynx, there may be a good early mucosal immune response.
16/24

Getting COVID19 infection has big risks for self & others, plus potential long term problems. Not a good thing & not advised to seek it.
17/24

I imagine a vaccine delivered in nasopharynx & lung tissue might be great. I'd defer that idea/possibility to viral/vax scientists.
18/24

Not long ago, polio vax was oral drops. It built immune response in lining of intestines where polio infection enters. I wonder if later the same idea could be used for COVID19 vax. We'll see.
19/24

For now, we have quite good injected vaccines for COVID19. As a society, the harm of infections can be massively cut, and perhaps eliminated IF ...
20/24

We all get vaccinated & in the meantime continue efforts to limit possible spread by masking & limiting time "sharing air" in close proximity to others.
21/24

Mucosal infections & positive tests after COVID19 vax are rarely true breakthrough systemic infection. It's a reminder that the virus is still floating about us & can be shared.
22/24

Later, COVID19 may become endemic, like a common cold, with vax preventing severe disease. Not as good as eliminated but may be reality, & is better than today!
23/24

But if some people still are getting sick from COVID19, it's floating about & may enter your nose ... 'cuz VAX DOESN'T FORM A BUBBLE AROUND YOU!
24/FIN