Heres an interesting conundrum. he got his second Jag on the 31st of May. I got my 2nd Jag on the 9th of June. Therefore he gets a booster @ 31st of November, and I get mine @ 9th December. Happy days except for one thing. We go to France from Ireland mid May 22, returning June 7th. Adding 6 mths to 31st Nov 21 means his booster runs out while in France, and mine doesn't. Mmnnn! Question is will the Irish need double Jag and booster proof? Also what will the French think of a vaccination booster not covering the trip? This is assuming the booster lasts 6 mths of course! Appreciate it if someone could tell me the validity period for double vaccinations and boosters? We live in N. Ireland btw so UK rules.