Is the Shingrix vaccine available in Thailand?  (I have already had the Zostavax vaccine, but I understand the newer one is much more effective).

No, not available yet. I am waiting for it as well.

Unfortunately the new shingles vaccine (Shingrix) is a two dose regimen to be effective.  Second dose is administered 2 to 6 months after the first.  When it was first offered the manufacturer did not have enough vaccine for the second dose, so many (myself included) were forced to eventually end up with 3 shots, in order to get the series done during the recommended time frame

 

So if it does make it's way to Thailand, only half of the battle will have been won, since you will need two doses 

 

Quote

source:  https://www.cdc.gov/vaccines/vpd/shingles/public/shingrix/index.html

 

3 hours ago, Langsuan Man said:

Unfortunately the new shingles vaccine (Shingrix) is a two dose regimen to be effective.  Second dose is administered 2 to 6 months after the first.  When it was first offered the manufacturer did not have enough vaccine for the second dose, so many (myself included) were forced to eventually end up with 3 shots, in order to get the series done during the recommended time frame

 

So if it does make it's way to Thailand, only half of the battle will have been won, since you will need two doses 

Exactly.  When I was in the US last year, my local veterans hospital offered me SHINGRIX but I would have had to stay for an additional six months for the 2nd unit.  I was told the 2nd unit had to be from the same production lot and that I could not transport it to Thailand with me for later injection as there was no way to guarantee it was properly stored at low temperature.

It is actually 2-6 month interval so if you can be in the US for 2 full months it is possible, but not  less than that. 6 months is the maximum interval.