Not that many people died in the first release. We didn't know back then that it even was a release. The first instalment of the horror that was to follow went mostly unnoticed. A few fringe media outlets ran the usual end of world stories, but as part of daily life they were mainly ignored. You couldn't even use the excuse of people not wanting to see what was going on in front of them, as it really was so unremarkable at first as to pass by the majority of the population without a flicker of warning of the desolate future that lay ahead.
Flu. The NHS warned of a expected severe flu outbreak that winter and for people to take all possible precautions. The number of casualties was anticipated to be higher than a average year but nothing to really be concerned over. The elderly and people with existing medical issues would be effected as usual and potentially a higher mortality rate than usual but the vast majority of the population would fight it off no problem.
Except that wasn't exactly what happened. People did get sick. A lot of people. And the elderly and vulnerable group were unable to fight it and died exactly as expected, but no higher than anticipated numbers. There were two things about this particular flu virus that made it very different to anything that ever came before but it was a long time before anyone noticed.
The first difference was the amount of relatively healthy people who couldn't fight the virus on their own. People who would not normally succumb to seasonal flu were having to visit the GP for anti biotics. A lot of people. Far higher than anyone would have anticipated. Not just once either, repeated visits for more anti biotics, as the damn thing just wouldn't go away. The people who should have been taking a lot more notice considered the numbers and decided it was a particular strain of flu that had developed a resistance to anti biotics and although slightly concerning, at this point nothing to really worry about. Not really.
The second thing that made this flu virus so massively different from anything ever known before went by completely unnoticed for a very long time. And yet, this was the one thing that really showed what type of madness had been unleased.