In the most recent London Review of Books, Hugh Pennington has a generally excellent article on measles and erroneous (to put it charitably) research linking the combined MMR vaccine to autism. It’s a pity therefore that, on a peripheral issue, he perpetuates an equally glaring error, saying
‘Most people have an intuitive appreciation that the best vaccine programme, from an individual’s point of view, is one where almost everyone else is vaccinated while they are not, so that they are indirectly protected without incurring any of the risks or inconvenience associated with direct protection.’ If too many people act in this way, the infection becomes commoner in the population as a whole, and returns as a real and significant threat to the unimmunised. This is a modern version of the ‘Tragedy of the Commons’ described by Garrett Hardin in his influential 1968 essay: 16th-century English peasants had free grazing on commons; their need to supplement food supplies and income was very great; the resulting overgrazing wrecked the commons for everyone.
As I’ve pointed out previously Hardin’s story was, in historical terms, a load of tripe.
It’s interesting to note that, in repeating Hardin’s story, Pennington adds the spurious specificity of “16th century England”, whereas Hardin’s account was not specific regarding dates and places, and therefore harder to refute. This is characteristic of the way in which factoids are propagated.