HaRav Yitzchok Zilberstein
We don't assume the position of preachers, but it is amazing to see what seforim note, that the pogroms of Tach and Tat which broke out after a cholera epidemic, were blamed by the rabbonim of that era on the fact that the public was not grateful enough for the miracle of the decline of the terrible plague.
Similarly, in "Lehagid" by HaRav Shalom Schwadron, and in "Tuvcha Yabiu" by HaRav Yitzchok Zilberstein), it connects to the posuk "And they forgot the miracles which He showed them." Therefore it followed that, "Hashem heard and became angry and fire broke out by Yaakov."
We, here in Israel, saw a tremendous salvation in the discovery of the vaccination, and at the time that we emerged from the dusk to the light, throughout the world people are still dying in the thousands and tens of thousands, day by day.
Indeed, when we see the technical aspect of the vaccine, especially since it was thoroughly discussed in public, it appears to be natural. But we must bear in mind that at the time that Pfizer produced the vaccine, scientists in other places also attempted to develop a vaccine in the same way and by the same method. They failed, while Pfizer and Moderna succeeded. This could have failed by a hairsbreadth by the same token, but had they not succeeded, we would be in a terrible condition to which degree we don't want to know.
The Chazon Ish once said that there is a special yetzer hora which causes people to forget a miracle and begin thinking that it was a natural process.
The Brisker Rov quoted the posuk, "And Moshe told his father-in-law all about what Hashem had wrought." There is a halachic obligation to retell miracles, as is written, "They retold His deeds joyfully." Rabbenu Yonah also writes that it is a mitzvah to remember the kindnesses of Hashem.
It is amazing to see what the Ramban says about why Moshe Rabbenu remained tongue tied. Why didn't the Healer of all Flesh heal him as well? It is because Moshe Rabbenu himself requested that a sign remain of the miracle so that he could thank Hashem and retell His wonders.