Thanks for all the replies to this. In summary, a few people sailed through with little discomfort; most were quite unwell after the first or second dose (more commonly the second), rarely both. But without exception, people said it was worth it, however unwell they felt. Many related their own experience of Shingles, or that of a close family member, asserting that it was MUCH worse than any side effects from the vaccine. So I will go ahead and get vaccinated ASAP, even though it's expensive here (nearly €500 for the two doses) and not covered by HSE (the national health service) at the moment.