*3.4. Petting Time*

There were eight out of nine possible successes, meaning that the time of interaction with their cats to reach a defined level of allergic symptoms for eight participants was greater at week 24 than the mean baseline of weeks 1–3 (Figure 3A). The change from mean 16.9 min (1016 s) at baseline to mean 27.7 min (1659 s) was statistically significant (*p* = 0.02). Of note, three participants had reached the maximum interaction time of 45 min by the end of the study.

**Figure 3.** Time of petting as part of the provocation test. (**A**) Mean petting time with SEM in seconds of nine participants comparing baseline (*n* = 3) versus week 24 at the end of the study. (**B**) Individual mean petting time with SEM in seconds at baseline (*n* = 3, weeks 1–3) compared to treatment period (*n* = 5, weeks 8, 12, 16, 20 and 24). (**C**) Factor of changed petting time for each participant shown as ratio of the mean timepoints during treatment (*n* = 5, weeks 8, 12, 16, 20 and 24) to mean baseline time (*n* = 3, weeks 1–3). (**D**) Change in % of the mean petting time with SEM of nine participants during the treatment period in weeks 8, 12, 16, 20 and 24 compared to mean baseline in weeks 1–3. Statistical significances were obtained by an exact Wilcoxon matched-paired signed rank test.

The improved petting time was apparent over the entire course of the study after vaccination of the cats in weeks 4, 7 and 10 (Figure 3B–D). On a per participant basis, the petting time was increased in seven of nine participants up to 6-fold (Figure 3B,C), which corresponded to an average improvement of 100%–230% across weeks 8, 12, 16, 20, and 24 compared to baseline (Figure 3D).

#### *3.5. General Weekly Symptom Score*

There were eight of possible nine successes, meaning that the GWSS of eight participants were lower at week 24 compared to baseline (Figure 4A). The mean GWSS at baseline compared to week 24 was significantly reduced from 7.2 to 4.4 (*p* = 0.023).

**Figure 4.** General weekly symptom score GWSS. (**A**) Mean GWSS with SEM of participants (*n* = 9) at baseline (*n* = 3, mean of weeks 1–3) versus week 24 at the end of the study. (**B**) Mean GWSS with SEM of participants (*n* = 9) at baseline (*n* = 3, weeks 1–3) and over the course of the study (*n* = 22, weeks 4–25). (**C**) Individual mean GWSS with SEM at baseline (*n* = 3, weeks 1–3) compared to treatment period (*n* = 22, weeks 4–25). (**D**) Mean GWSS with SEM of nine participants comparing baseline (*n* = 3, weeks 1–3) vs. treatment period (*n* = 22, weeks 4–25). Statistical significances were obtained by an exact Wilcoxon matched-paired signed rank test. Possible GWSS values from 0–30.

The average GWSS of all participants over the entire study period was also assessed (Figure 4B–D). Towards the end of the study, the mean GWSS was consistently lower than the baseline values (Figure 4B). Comparing the average baseline with the average treatment values of the GWSS, a change in the general allergic symptoms (*p* = 0.039) was observed in eight of nine participants, demonstrating a persistent improvement in symptoms upon immunization of the cats (Figure 4C,D).
