Australia's population is 24 million people and in 2015 Australia received 7.4 million visitors. This equates to approximately 30% of Australia's population arriving during the course of 12 months.
No, not 30% but about 1% since the tourists are not there for the whole year, right?
Most tourists stay 1-2 weeks (and often tourists are the ones getting the most vaccinations). And a lot of them are vaccinated.
But let's say the majority are not. That leaves you with 5 million people.
They are in the country for 1 week. Makes about 100K "year-people-equivalents".
Or halve a percent for the 24 million population.
Also tourists tend to be concentrated in one place, making an epidemic far less likely, but maybe concentrating sickness in hotels.
however most illnesses have a time (I don't know the english word) it takes from getting the virus yourself until the time you are able to infect another person.
So even if a tourist gets infected in your country he might already have left the country by the time she is dangerous.
Great point. Most tourists check with their doctors before visiting a foreign country to see what diseases are particularly prevalent and get vaccinated against them before travelling. This plus the fact that the number of tourists is very low in comparison to actual residents means herd immunity may probably not be affected that much. However the article does make a good point that herd immunity could be influenced with a large number of visitors. I personally believe herd immunity is very important, and stops the spread of many infectious diseases.