In my post arguing that elderly vaccination saved lives, I presented the following chart as evidence that vaccine effectiveness has been overestimated. It shows a large spike in excess mortality in South Korea, coinciding with the country’s Omicron wave.
The spike occurred after 90% of over 80s had been double-vaccinated, and was comparable to spikes that occurred in other countries before anyone was vaccinated. This casts doubt on claims of 90% vaccine effectiveness against death.
On the other hand, if we compare South Korea to an East Asian country with a much lower vaccination rate among the elderly, we find evidence that the vaccines were effective against death.
Like South Korea, Hong Kong managed to contain the virus for the first two years of the pandemic. Then in February of 2022, both countries were hit by the Omicron variant and the virus began spreading rapidly. This makes the pair ideal for testing claims about vaccine effectiveness.
According to the Hong Kong government, only around 25% of over 80s had been double-vaccinated by 31st December, 2021. By 4th March, it was still only 30%. This means that when Omicron hit, 90% of South Koreans over 80 were double-vaccinated, compared to less than 30% of HongKongers over 80.
Which, in turn, almost certainly explains why Hong Kong saw a much greater spike in excess mortality than South Korea, as shown in the left-hand chart below.
One might object that Hong Kong is a densely-populated city state, or that Hongkongers are different from Koreans. Yet if we compare Hong Kong to Singapore – which is also a densely-populated city state, inhabited mainly by the ethnic Chinese – we see the very same pattern.
As shown in the right-hand chart above, Hong Kong saw a much greater spike in excess mortality than Singapore. And as in South Korea, 90% of over 80s in Singapore were double-vaccinated when Omicron hit.
At the time, Hong Kong’s overall vaccination was fairly high – 64%, about the same as Israel’s. Which indicates that elderly vaccination, rather than vaccination in general, is what matters – consistent with the argument in my earlier post.
The evidence from Hong Kong, South Korea and Singapore suggests that vaccine effectiveness against death is lower than 90% but still greater than zero. Vaccinating the elderly in these countries saved lives too.