Table 3. Additional RSVpreF Vaccine Effectiveness (VE) Estimates Against Respiratory Syncytial Virus (RSV)–Related Lower Respiratory Tract Disease (LRTD) Hospitalizations or Emergency Department Visits by End Point Type, Kaiser Permanente Southern California Network, November 2023 to April 2024.
| Patients, No. (%) | VE (95% CI) | |||||
|---|---|---|---|---|---|---|
| Test negative (strict control definition)a | Test positive | Crude | Adjustedb | |||
| Unvaccinated | Vaccinated | Unvaccinated | Vaccinated | |||
| VE against RSV-related LRTD hospitalizations (n = 692)c | 380 (96.9) | 12 (3.1) | 299 (99.7) | 1 (0.3) | 89 (18 to 99) | 87 (−8 to 98) |
| VE against RSV-related LRTD hospitalizations among patients with high-risk chronic medical conditions (n = 683)d | 375 (96.9) | 12 (3.1) | 295 (99.7) | 1 (0.3) | 89 (18 to 99) | 87 (−6 to 98) |
| VE against RSV-related LRTD ED visits (n = 735) | 395 (95.9) | 17 (4.1) | 322 (99.7) | 1 (0.3) | 93 (45 to 99) | 93 (45 to 99) |
| VE against severe RSV-related LRTD hospitalizations and ED events (n = 719) | 389 (96.8) | 13 (3.2) | 316 (99.7) | 1 (0.3) | 91 (27 to 99) | 89 (13 to 99) |
Abbreviation: RSVpreF, Respiratory Syncytial Virus Prefusion F.
A case is considered positive for RSV. A control is considered positive for a nonvaccine preventable disease and negative for RSV, human metapneumovirus, and vaccine preventable diseases. Identified pathogens included adenovirus, Chlamydia pneumoniae, coronavirus (229E, HKU1, NL63, and OC43), human rhinovirus/enterovirus, parainfluenza (serotypes 1-4), and Mycoplasma pneumoniae.
VE was adjusted for age, sex, encounter months, race and ethnicity, Charlson index, previous outpatient encounters, previous inpatient encounters, and previous ED encounters.
95% CI included for this end point provided for comparability with other end points; formal prespecified interim analysis for this end point used a 99.99% CI which was (−754 to 100).
This estimate is limited to those at high risk for severe disease based on underlying comorbidities, including asthma; chronic obstructive pulmonary disease; congestive heart failure; coronary artery disease; other chronic lung, cardiac, kidney, or liver diseases; diabetes; neurological conditions; stroke; autoimmune disorders; immunocompromising conditions and medications; HIV; AIDS; cancers; organ transplant; and blood disorders.