It is highly unlikely (albeit not impossible) that a vaccine will be developed this year, but vaccinating 70% of the developed world (why leave out the US?) is pure fantasy on any timescale, let alone less than a year.
There are at least seven vaccines being tested on humans or about to be, all from reputable labs with good track records. There is I agree no guarantee but the track record suggests that about 2 will become commercial. I am more optimistic than you. We do indeed vaccinate 70% or more of the susceptible in the developed world with flu vaccine every winter and the only reason we dont vaccinate 70% of more people is cost. We universally aim to vaccinate with MMR and other vaccines and achieve well over 70%. If the money is there to manufacture, 70% is achievable in
about a year. The reason I say not the USA is simply because their record with flu vaccine is abysmal primarily because it isnt free at point of use, and the price isnt 'cost plus' but many times more. Hence the US death rate per million population is higher due to less vaccination.
For the majority however, the extra alcohol and takeaways they’re consuming during this intervening period is more likely to be injurious to their health than novel coronavirus.
True, because if fully locked down the risk of Covid-19 is effectively zero. However without lockdown we may have seen 924,000 deaths over a matter of months. That is a lot of takeaways