British Expats - Vaccination record missing

Hi can someone help...

My dad is currently in the process of getting his ir1 visa. He has lived and worked in the US for 19 years before returning to the UK for 17 years and is now ready to return with my mom to the US. The only problem is when he requested his vaccination record from his gp surgery it only has two listed. One tetanus and one flu jab. Is there anyway around the vaccination record for the medical if he lived in the US already on a student visa and then a spouse visa and had to have all the relevant vaccinations for those. The problem I think is that his dr office here in the US that he used to go to no longer exists and then previous to that I think they didn't do digital files. Any advice would be helpful. Thank you.