I think you missed one of the more obvious options
That was 4. Something else
Due to lockdowns etc the number of people infected fell to a very low level.
With restrictions eased, levels of infection have started to increase in various countries.
Cases, especially mild or asymptomatic cases, are far more likely to actually be counted now because testing capacity etc changed a lot compared to the first wave.
So, even though cases are rising, they are still a very small number of cases at any one time compared to the actual number of people that were infected at any one time during the peak of the first wave.
And this low number of current infections is reflected in hospitalisation and death stats.
If numbers infected, and demographics involved, go back up beyond a certain level, rises in hospitalisations and deaths will be expected to rise too.
But due to changes in testing etc, we would not expect to see the ratio of positive cases:deaths to be the same as the first time around.
So if in March there were 5000 cases detected on a particular day and 500 deaths that day, and then in September we see a day with 5000 cases detected but only 15 deaths, I do not need to look far for explanations (these are made up numbers for illustration only). Because I do not make the mistake of thinking that because these were both days with 5000 detected cases, that the wave of infections was actually at a similar level on both those occasions. So I wouldnt expect the death rates to resemble each other either.
Anyway thats the sort of scenario I use as a foundation, and then various other possibilities can be tacked on top if some evidence emerges to suggest that there is more going on.
I think that's probably most likely.
/Grabs back of fag packet and hits the ONS site to look at the figures/
There's currently about 1,000 cases per day being reported.
The current numbers of deaths is not completely clear - the official daily figure has been between 2 and 16 this week, but we know the ONS figure will be higher. Let's guess at around an average of 15 deaths per day.
That's about 67 infections per death every day.
During the peak week in April an average of around 1,300 per day were dying.
There are, of course, no figures for infections during the peak as the government gave up testing outside hospitals when things were really taking off (partly because they didn't have the capacity and partly because herd immunity). But if the ratio has remained constant that would mean a jaw dropping 87,100 people were being infected every day at the peak.
Can that be right?
Well, according to an
Imperial College study "slightly under 6% of the population may have antibodies for the virus by the end of June – an estimated 3.4 million people." For all those people to have been infected in the 5 months from February to June, there would be an average infection rate of around 22,333 people per day. That infection rate wouldn't be constant - not many would be getting infected at the beginning of February, loads would be getting infected in mid-March and the numbers would drop significantly after lockdown. That means the 87,100 infections per day figure, or one even higher, at the peak is quite believable.
So yeah, if I haven't completely fucked up my maths (and I did get a U in my maths A-level) it looks like the numbers do support your theory.