static Physician Global Assessment (sPGA) 0 or 1 response assessed as a percentage of participants with a sPGA score of 0 or 1 as assessed at week 16 with at least a 2-point improvement from baseline. The sPGA is a 5-point scale of an average assessment of all psoriatic lesions based on erythema, scale, and induration. The sPGA measure determines psoriasis severity at a single point in time (without taking into account the baseline disease condition) as clear (0), almost clear (1), mild (2), moderate (3), or severe (4). A higher score equates to higher severity of disease. The individual scores at each visit will range from 0-4 and will be captured for erythema, induration, and scaling. A total score will also be computed based on the average of the 3 characteristic scores. The average score will be rounded to the nearest whole number and data for this endpoint will be derived from the total average score.

Psoriasis Area and Severity Index (PASI) 75 response is an assessment defined as the percentage of participants who experience at least a 75% improvement in PASI score at Week 16 as compared with baseline value. PASI is a measure of the average redness, thickness, and scaliness of psoriatic skin lesions graded on a scale from 0-4 (0= absent symptoms, 1= mild symptoms, 2= moderate symptoms, 3= severe symptoms, 4= very severe symptoms), weighted by the area of involvement (head, arms, trunk to groin, and legs to top of buttocks). The PASI produces a numeric score that can range from 0 to 72, with higher PASI scores denoting more severe disease activity. The PASI includes multiple subscores and a final total score. Individual plaque characteristic rating scores are provided for each body region as well as the weighted score. The PASI Total score will be used to assess response to treatment.

Vaccine cohort only Defined as ≥ 2-fold increase in immunoglobulin (IgG) antibody titers or geometric mean fold rise (GMFRs) titers of ≥ 6

Vaccine cohort only A serologic response is defined as: * Postvaccination titer levels ≥ 0.40 IU/mL if prevaccination IgG antibody titer level is ≤ 0.10 IU/mL OR * Postvaccination titer levels of at least a 4-fold increase if prevaccination titer level is \> 0.10 IU/mL and ≤ 2.7 IU/mL OR * Postvaccination titer levels of at least a 2-fold increase if prevaccination titer level is \> 2.7 IU/mL

The sPGA is a 5-point scale of an average assessment of all psoriatic lesions based on erythema, scale, and induration. sPGA 0/1 is the response as a number of participants who experience a sPGA score that determines psoriasis severity as clear (0) or almost clear (1) with at least 2-point improvement from baseline at week 16 using the non-responder imputation (NRI) method. The higher sPGA score denotes to more severe disease activity: * Clear (0) * Almost clear (1) * Mild (2) * Moderate (3) * Severe (4)

PASI is a measure of the average redness, thickness, and scaliness of psoriatic skin lesions (each graded on a 0 to 4 scale; 0 = none to 4 = very severe), weighted by the area of involvement (head, upper extremities, trunk, and lower extremities). The PASI produces a numeric score that can range from 0 to 72, with higher PASI scores denoting more severe disease activity. PASI 75 is the response as a number of participants who experience at least a 75% improvement in PASI score as compared with the baseline value using the non-responder imputation (NRI) method.

The sPGA is a 5-point scale of an average assessment of all psoriatic lesions based on erythema, scale, and induration. The average of the 3 scales, which is rounded to the nearest whole number, is the final sPGA score. The higher sPGA score denotes to more severe disease activity (0 = Clear; 1 = Almost clear; 2 = Mild; 3 = Moderate; Severe = 4). sPGA 0/1 is the response as a number of participants who experience a sPGA score that determines psoriasis severity as 0 or 1 with at least 2-point improvement from baseline using the non-responder imputation (NRI) method that will be used for participants who discontinue treatment or study prior to week 16 or who have missing week 16 endpoint data for any reason.

PASI is a measure of the average redness, thickness, and scaliness of psoriatic skin lesions (each graded on a 0 to 4 scale; 0 = none to 4 = very severe), weighted by the area of involvement (head, upper extremities, trunk, and lower extremities). The PASI produces a numeric score that can range from 0 to 72, with higher PASI scores denoting more severe disease activity. PASI 75 is the response as a number of participants who experience at least a 75% improvement in PASI score as compared with the baseline value using the non-responder imputation (NRI) method that will be used for participants who discontinue treatment or study prior to week 16 or who have missing week 16 endpoint data for any reason. Baseline is defined as the measurement at the randomization visit (Week 0).

Psoriasis Area and Severity Index (PASI) 75 response: patients who achieved ≥ 75% improvement (reduction) in PASI score compared to baseline were defined as PASI 75 responders. PASI scores can range from 0, corresponding to no signs of psoriasis up to theoretical maximum of 72.0, which means a higher PASI score reflects a higher psoriasis activity.

The safety and tolerability of BMS-986195 as assessed by the number of subjects with adverse events (AEs); number of subjects with serious adverse events (SAEs); number of subjects with adverse events leading to discontinuation