booster needed?

Not an expert on this, but the last I read seemed to indicate a booster that was given at least 7 days prior to arrival in France was required. It certainly could change, but one easy solution is simply to get the booster. If you have reasons why that is not an acceptable choice for both of you, then I probably would change my plans to go elsewhere.

The requirements are fluid, as is the pandemic. It is difficult to know from one day to the next what will happen.

Fully vaccinated for entry into France means you have received 3 doses, the 3rd, the booster, being a mRNA vaccine.

https://www.interieur.gouv.fr/covid-19-international-travel#from2

Thank you Carol and Tocard for your quick response to my query. I now see that France does indeed require a booster at this time. Somehow I didn't see that site. I guess France will have to wait. Carol, my husband has had some neurological issues since his vaccination and is unwilling to be boosted at this time.

You will need the booster as it stands now. You might though consider the timing of the booster somewhat. There has been debate over whether to put an "expiration" on the booster, with some countries saying 9 months, some 6, some not addressing it. Problem is, no fourth booster has been agreed upon, and with the Omicron variant in decline, countries will probably defer any action...until the next variant. You have waited this long, waiting a month or so for the booster might be an option, assuring plenty of effectivity left in June. Of course the various countries may agree that just having the booster, regardless of when, is sufficient.