I mean #1 has been widely debunked and in #2 they didn't test against Delta or Omicron. Maybe the results generalize but from the adult studies we've seen all show reduced neutralizing responses to Delta and Omicron as compared to the original strain.
Prior infection seems better against Delta but omicron is it's own thing as in immunity is not maintained. Interestingly omicron infection may protect against delta however.
"Plasma samples from 19 children and 18 adults at >6 months after primary infection were tested for binding to spike and RBD from Alpha (B.1.1.7), Beta (B.1.351) and Gamma (P.1) variants compared to the original Wuhan genotype, which was used in previous assays."
Prior infection seems better against Delta but omicron is it's own thing as in immunity is not maintained. Interestingly omicron infection may protect against delta however.
https://www.imperial.ac.uk/news/232698/omicron-largely-evade...
"Plasma samples from 19 children and 18 adults at >6 months after primary infection were tested for binding to spike and RBD from Alpha (B.1.1.7), Beta (B.1.351) and Gamma (P.1) variants compared to the original Wuhan genotype, which was used in previous assays."