As more information is discovered, it looks like maybe the blood clotting problems soon after vaccination is causal and not coincidence. Research has shown that the spike protein can lead to an attack on blood vessels, and the common vaccines right now flood the body with spike proteins.
This has made several countries concerned enough that they have paused vaccinations because of the issue, but given that the side effects are more rare than COVID, some people are saying that the vaccinations should continue. And now it looks like most of the countries were following Germany, afraid to be the odd one out.
This article (Google Translated) suggests that the problem is in incorrect vaccination technique. Apparently for intramuscular shots, you’re supposed to draw back the plunger slightly to see if you hit a blood vessel, and move the needle if you see blood. The article says that if the vaccine gets into the blood (instead of the lymph system where it is supposed to be), then it can get places it shouldn’t and cause inflammation and from there, clotting.
See also this Twitter thread, which has more detail.
Yet another article which says that the mRNA vaccines are unfazed by B.1.1.7, are slightly less effective against P.1 and B.1.427/9, but still effective enough; even less effective against B.1.351, but still effective enough.
A Danish study says that one bout of COVID-19 gives about 80% protection for at least six months, though that protection seems to be significantly lower — possibly to a little less than 50% — for the elderly. The second bout is usually much milder than the first, though.
The study also found that the protection that people got from a natural infection varied quite a bit; the protection from vaccination was more uniform and higher.