Why don't some countries vaccinate against chickenpox?

 https://www.bbc.com/future/article/20240229-why-dont-some-countries-vaccinate-against-chickenpox

However, the decision not to vaccinate children against chickenpox is down to more than budget constraints – in many parts of the world, it's a calculated risk that aims to prevent disease in a different group: older adults.   

In the last five years, opinions has begun to shift following large-scale epidemiological studies which have shown that the US and other countries have not actually seen the feared increase in shingles cases over the last three decades. One UK study even estimated that the supposed immunity boosting effect of adults exposed to infected children might be less impactful than previously thought.

"What has changed in the last few years is that we now have very clear evidence from the US that shingles rates did not increase any faster after the vaccine was introduced and if anything, have somewhat levelled off in recent years," says Pollard. "The improved certainty about this has really made the cost-effectiveness modelling more robust." 

There are signs that other countries are also beginning to shift their mindset on the vaccine. Marie Studahl, a professor at the University of Gothenberg in Sweden, said that she welcomed the UK recommendation, and expressed hope that Norway, Denmark and Sweden will soon implement varicella vaccination. "In Sweden we have been waiting a very long time for this… I am convinced that doctors are mostly positive to implementation," she says.