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In the case you pointed out, 200,000 children were vaccinated in 1955 with a batch of defective polio vaccine where the virus was insufficiently inactivated. 200 children suffered partial paralysis and 10 died as a result. This was a disastrous accident.
1/ https://twitter.com/JuanchoRadek/status/1334189801784946690
1/ https://twitter.com/JuanchoRadek/status/1334189801784946690
It is exceptionally unlikely that such an accident could happen with #COVID19 vaccines. None of the frontrunner vaccines are 'live' attenuated vaccines, as such they cannot cause infection. Also, modern vaccines are expected to be produced under far higher safety standards.
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That said, accidents can happen and no medical procedure is 100% safe for everyone, ever. Rare side effects are also expected when millions of people get vaccinated. The case for vaccination is based on a utilitarian cost/benefit argument.
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Given the high fatality rate of #COVID19, the cost/benefit ratio of any vaccine - even ones that might be far less safe than the ones under advanced development - would be extremely favourable at the level of the population.
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A feature of #COVID19 is the exceptional heterogeneity in mortality, with close to a ~100,000x higher risk of death for the elderly relative to young children. The risk ratio may be even higher when comorbidities are additionally factored in.
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https://www.nature.com/articles/s41586-020-2918-0
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https://www.nature.com/articles/s41586-020-2918-0
The incoming vaccines look highly safe and will undoubtedly have an overall mean positive benefit-over-risk ratio for any population. Though, assuming rare side effects are evenly distributed, vaccines will be ~100,000x more beneficial for the most at-risk in society.
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Given the age heterogeneity in #COVID19 mortality, it feels a complete no-brainer to me that the most at-risk in society should be vaccinated in absolute priority. Once this will be achieved, higher population coverage can be considered, I believe, on a voluntary basis.
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I worry that once those most at-risk will have been vaccinated, the bitter discussions about the ethics of 'herd immunity' strategies may be back on the table. I don't dare to envision how toxic the discussion about vaccinating children for #COVID19 could be.
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