Does it? Honest question. I don't know and want to learn more.
From the article (and presumably from the data in the peer reviewed study), the vaccine is 92% effective at preventing confirmed infection of its recipients starting 7 days after the second dose, with lower effectiveness at prior times. For instance 60% during the time between doses. So, short answer: yes, the vaccine does appear to be effective at reducing transmission of the virus and not just effective at preventing illness or death from it.
“vaccination chokes off transmission - Does it?”
Yes, it does. As people develop heightened immune responses to the virus, whether by vaccination or exposure to the virus, several measurable effects occur.
Those people become: less likely to fall sick, less likely to become seriously sick if they do develop illness, less likely to die if they were to become seriously sick, and overall less likely to transmit the disease to others.
How much less likely? For both those naturally exposed, and for those receiving the Pfizer or Moderna vaccines, it is better than 90% reductions.
By some estimates, more than half of the American population (up to 2/3rds) may have already been exposed to the virus through wild transmission. At least over a quarter has been demonstrated through random blood testing (CDC’s seroprevalence survey) - but that did not begin until sometime after spread was already high in NYC, so earlier cases were likely missed (the antibodies they test for are only detectable for 1-2 months after infection). So natural herd immunity may be approaching rapidly - perhaps April, by some optimistic estimates.
18% of American adults have already received a first shot of vaccine, and we are running at a rate of about 10% of the population per month with vaccination. That rate should increase, as new producers begin providing additional supplies - Johnson & Johnson is expected to be authorized this weekend. AstraZeneca and Novavax are expected to gain authorization in April.
Defense Procurement Act contracts have been made, and paid for, for a tidal wave of vaccine:
Moderna - 300 million doses by the end of June
Pfizer - 300 million doses by the end of July
Johnson & Johnson - 100 million by the end of June (single shot vaccine)
Novavax - 100 million doses (expected by the end of June, subject to timely authorization)
AstraZeneca - 400 million doses!
Over a billion doses in the next few months are likely. Talk about choking off transmission!
We will see the effects in Israel first, as they are ahead of the rest of the world in vaccinating their population. They plan to get to everyone (about 9 million) by April 10th. Over 90% of their over 65 year olds have already had their first shot.
The virus is going to increasingly find a dead end, as it jumps from one person to another. Somewhere between April and June, it will dwindle away to a low rate endemic disease in the background - just another case of coughs, that kids get over while growing up. They will keep pushing the vaccine through Summer to get most all adults, and likely reformulated booster shots (for the variants) in the Fall (like the flu shot).
But the bottom will soon drop out of the numbers for cases, hospitalizations and deaths; because the virus just won’t be able to transmit at a replication rate high enough to keep spreading.