The Swiss Cheese Theory of Coronavirus

Many countries are mired in a tough fight against the second wave of coronavirus. To win it, governments are seeking various restrictive measures that reduce social contact and slow down the chain of infections: curfews, hygiene recommendations, closure of hotels, gyms, schools … However, some scientists argue that no measure is as effective as the union of all. They explain this idea with the ‘Swiss cheese theory’.

What is the Swiss cheese theory?

Virologist Ian Mackay, associate professor at the University of Queensland (Australia), recently exposed this model of Swiss cheese applied to the pandemic, noting that no method is infallible because there can be failures or errors that make the coronavirus cross that barrier. However, all the measures added increase its reliability. Relate this fact to perforated slices of Emmental cheese. Each of these is a measure that will let the virus pass, but if they are combined effectively, plugging the gaps, they can create a very consistent wall against the virus.

Altogether, Mackay talks about ten slices overlapped in such a way as to prevent transmission. The first five would be related to individual responsibility, while the other five remain in the hands of the social and administrative responsibility:

1. Respect the social distance Y stay at home if we are sick or feel symptoms.

2. Use mask.

3. Maintain a good hand hygiene.

Four. Avoid touching our faces too.

5. Do not stay long in crowded placesespecially if it is indoors.

6. Make a good contact tracing to later make them fast and very sensitive tests.

7. When we are indoors it is important to maintain a good ventilation with air filtration systems. In any case, it is advisable to carry out all the activities that we can when fresh air.

8. Communicate the regulations well to the population, with clear messages to prevent confusions. Further, the administrations must financially support the measures aimed at fighting the pandemic.

9. Monitor the isolation of confirmed cases and quarantine of contacts.

10. Finally, there would be the creation of vaccines. But, while this long-awaited event arrives, it is essential to respect the above.


Like all theories, this one has its defenders and detractors. Tomás Pueyo, the engineer who advanced the impact of the first wave, was in favor of this idea in an interview on Antena 3, noting that China and the rest of Asia combined these slices of cheese well to slow the curve. On the other hand, according to Il Corriere della Sera, other scientists criticize this model, claiming that the coronavirus presents other variables to take into account, starting with your own virus behavior, which is very changeable. Other factors would also enter such as type of space in which it is (open or closed), the territory (a town or city, for example) or the application time of the measure.