[oldalum]

I know three people so far who have been unable to get the CA vac certificates

digital photo of vaccine card will suffice: 

(from Stanford's website)
For proof of vaccination, individuals 18 and older must show a photo ID that matches the name on their vaccine record. Acceptable proof of vaccination includes a vaccine card (hard copy, paper photocopy, or clear digital photo) or a State of California digital COVID-19 vaccine record. Vaccination documentation must clearly indicate:

• Full Name
  
  
• Birthdate
  
  
• Vaccine name/manufacturer
  
  
• Date(s) of vaccination 
  

[oldalum]

I know three people so far who have been unable to get the CA vac certificates

digital photo of vaccine card will suffice: 

(from Stanford's website)
For proof of vaccination, individuals 18 and older must show a photo ID that matches the name on their vaccine record. Acceptable proof of vaccination includes a vaccine card (hard copy, paper photocopy, or clear digital photo) or a State of California digital COVID-19 vaccine record. Vaccination documentation must clearly indicate:

• Full Name
  
  
• Birthdate
  
  
• Vaccine name/manufacturer
  
  
• Date(s) of vaccination