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NCT Number: NCT06077968

A Study to Learn About ABRYSVO Vaccine in Older Adults to Prevent Severe Respiratory Syncytial Virus (RSV) Disease

The main purpose of this study is to learn about the effectiveness of Pfizer's ABRYSVO vaccine. This vaccine helps to prevent infections caused by Respiratory Syncytial Virus (RSV). RSV is a virus that can cause infections in the airways. These symptoms can be cold-like symptoms, but in some cases can lead to severe symptoms or hospitalization.

This study uses only healthcare data that are already collected from routine visits to healthcare providers. This means that participants will not be actively enrolled in the study and there are no study treatments. The study will look at data for about two years. This study will look at patient information from:

* Adults ages 60 years and older * Adults who are eligible to receive the ABRYSVO vaccination

Substudy A:

* This study will assess the duration of protection of ABRYSVO in adults ages 60 years and older after completion of the original study. * The substudy will look at data from subsequent RSV seasons after the first dose of ABRYSVO for about 5 years.

Substudy B:

* This study will assess vaccine effectiveness of ABRYSVO after revaccination in routine use, pending ACIP recommendation for revaccination. * The substudy will look at data for about 2 years after revaccination.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

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Key information

Conditions

Respiratory Syncytial Viruses

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Pfizer

New York, 10001, United States

About this study

The overall research question asks how effective ABRYSVO® is against severe RSV disease in real-world populations. The primary objective of this study is to estimate the VE of Pfizer's ABRYSVO® vaccine against RSV-related LRTD hospitalizations among Kaiser Permanente Southern California members who are eligible for vaccination per Advisory Committee on Immunization Practices (ACIP) recommendations. Key secondary objectives include determining ABRYSVO® VE against RSV-related LRTD hospitalizations among the immunocompetent and stratified by age group (60-74 years vs 75 years and older). Additional secondary objectives include assessment of ABRYSVO® VE stratified by RSV subgroup, against ARI endpoints, death, among high-risk subgroups, and against critical outcomes.

A case control study with test negative design will be the primary analysis assessing RSV-related outcomes. An exploratory cohort design may also be used to assess all-cause outcomes and RSV-related outcomes.

Standard-of-care specimens (e.g. stored remnant respiratory specimens) from patients who did not receive RSV testing, who tested negative for RSV via RSV-only test, or a had limited multiplex viral respiratory panel assay will be salvaged and tested using a full respiratory multiplex polymerase chain reaction (PCR) panel at KPSC. Further, all RSV positives will be tested for RSV A and RSV B.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • KPSC patients eligible to receive ABRYSVO® per ACIP recommendations for adults ages 60 and older who are admitted to the hospital with ARI/LRTD, (defined using International Classification of Diseases (ICD) codes after start of study period, and who have had an RSV test, either through SOC testing or blinded study testing of remnant respiratory specimens.
  • For secondary objectives estimating VE against ED admission, the TND will include KPSC patients eligible to receive ABRYSVO® who present to the ED with ARI/LRTD after start of study period, and who have had an RSV test, either through standard of care testing or blinded study testing of remnant respiratory specimens.
  • For exploratory objectives estimating VE against RSV-related cardiac hospitalization, the TND will include KPSC patients eligible to receive ABRYSVO® who are hospitalized or present to the ED with cardiac events (defined using ICD codes) after start of study period, and who have had an RSV test, either through SOC testing or blinded study testing of remnant respiratory specimens.
  • We will include membership requirement of 1 year prior to index date, which is defined as the date of hospitalization or ED admission (allowing 45-day administrative gap), to facilitate accurate capture of comorbid conditions.

Exclusion criteria

Patients meeting any of the following criteria will not be included in the study:

We will exclude patients who receive another licensed or investigational RSV vaccine prior to hospitalization or ED visit from the study population and analysis. Patients will be excluded if the index date is within certain time windows from vaccination date, outlined further in the exposure section below.

SSA and SSB Eligibility Criteria:

The inclusion criteria for Substudy A are described above for the Test Negative Design.

Treatment and study plan

Prior standard of care receipt of Pfizer's ABRYSVO vaccine

Biological

Participants will receive Pfizer's ABRYSVO vaccine as part of standard of care. Vaccine is not administered in this study.

Primary outcomes

  1. 1. Vaccine Effectiveness (VE) calculated as 1 minus the odds ratio (OR) comparing the odds of being vaccinated with ABRYSVO for RSV-related hospitalized LRTD cases and controls, multiplied by 100%.

    Time frame: Up to 2 years

    Adjusted for confounding factors using logistic regression. To estimate the effectiveness of ABRYSVO against RSV-related LRTD hospitalizations

  2. SSA Primary: To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations during the 3rd RSV season after a single dose

    Time frame: Up to 3 years

    Among those with 3 completed RSV seasons after vaccination with a single dose of ABRYSVO®, VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for RSV-related hospitalized LRTD cases and controls, multiplied by 100%, using LRTD events from the 3rd season

Secondary outcomes

  1. Key Secondary 1: Among the immunocompetent, VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for RSV-related LRTD hospitalizations cases and controls, multiplied by 100%.

    Time frame: Up to 2 years

    Adjusted for confounding factors using logistic regression. To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations among the immunocompetent.

  2. Key Secondary 2: ABRYSVO® VE estimates stratified by age group

    Time frame: Up to 2 years

    To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations stratified by age group (60-74 years vs 75 years and older)

  3. Secondary 3: To further describe the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations stratified by RSV subgroup (A and B)

    Time frame: Up to 2 years

    Adjusted for confounding factors using logistic regression. ABRYSVO® VE estimates stratified by virus subgroups

  4. Secondary 4: VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for RSV-related severe LRTD cases and controls, multiplied by 100%

    Time frame: Up to 2 years

    Adjusted for confounding factors using logistic regression. To estimate the effectiveness of ABRYSVO® against RSV-related severe LRTD.

  5. Secondary 5: ABRYSVO® VE estimates stratified by frailty index

    Time frame: Up to 2 years

    Adjusted for confounding factors using logistic regression. To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalization stratified by frailty index.

  6. Secondary 6: ABRYSVO® VE estimates stratified by chronic medical condition risk category

    Time frame: Up to 2 years

    Adjusted for confounding factors using logistic regression. To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations, stratified by chronic medical condition risk category (3 strata: not high-risk conditions, immunocompromising high-risk conditions, non-immunocompromising high-risk conditions).

  7. Secondary 7: VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for RSV-related hospitalized LRTD cases and controls, multiplied by 100%, among those with CHF or COPD

    Time frame: Up to 2 years

    Adjusted for confounding factors using logistic regression. Among those with congestive heart failure (CHF) or Chronic Obstructive Pulmonary Disease (COPD,) to estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations

  8. Secondary 8-1: VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for ED (without subsequent hospitalization) cases and controls, multiplied by 100%

    Time frame: Up to 2 years

    Adjusted for confounding factors using logistic regression. To estimate the effectiveness of ABRYSVO® against ED admission (without subsequent hospitalization)

  9. Secondary 8-2: VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for hospitalized or ED visit (without subsequent hospitalization) cases and controls, multiplied by 100%.

    Time frame: Up to 2 years

    Adjusted for confounding factors using logistic regression. To estimate the effectiveness of ABRYSVO® against ED (without subsequent hospitalization) or hospitalization

  10. Secondary 9: VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for RSV-related death cases and controls, multiplied by 100%.

    Time frame: Up to 2 years

    Adjusted for confounding factors using logistic regression. To estimate the effectiveness of ABRYSVO® against RSV-related death

  11. Secondary 10-1: VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for hospitalized RSV-related ARI cases and controls, multiplied by 100%

    Time frame: Up to 2 years

    Adjusted for confounding factors using logistic regression. To estimate the effectiveness of ABRYSVO® against RSV-related ARI hospitalization

  12. Secondary 10-2: VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for RSV-related ARI ED visit (without subsequent hospitalization) cases and controls, multiplied by 100%

    Time frame: Up to 2 years

    Adjusted for confounding factors using logistic regression. To estimate the effectiveness of ABRYSVO® against RSV-related ARI ED visits (without subsequent hospitalization).

  13. TND Secondary 10-3: VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for ARI ED visit (without subsequent hospitalization) or ARI hospitalized RSV-related cases and controls, multiplied by 100%

    Time frame: 2 years

    Adjusted for confounding factors using logistic regression. To estimate the effectiveness of ABRYSVO® against RSV-related ARI hospitalization or ARI ED visits (without subsequent hospitalization)

  14. TND Secondary 11: Describe age, sex, race/ethnicity, clinical and laboratory characteristics, and disease severity (LOS, ICU admission, respiratory support) of any patients who received ABRYSVO® and tested positive for RSV as compared to unvaccinated

    Time frame: Up to 2 years

    To describe demographic, clinical, and laboratory characteristics and disease severity of any RSV events among vaccinated individuals as compared to unvaccinated

  15. Secondary 12: ABRYSVO® RSV-related VE estimates stratified by age group and chronic medical risk categories

    Time frame: Up to 2 years

    Adjusted for confounding factors using logistic regression. To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations stratified by age group and chronic medical risk categories.

  16. Secondary 13: ABRYSVO® VE estimates stratified by immunocompromised status

    Time frame: 2 years

    Adjusted for confounding factors using logistic regression. To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations stratified by (1) immunocompromised vs immunocompetent, and separately (2) within those with immunocompromising condition, by severe vs moderate immunocompromised status.

  17. Secondary 14: VE calculated as 1 minus the odds ratio (OR) comparing the odds of being vaccinated with ABRYSVO® for hMPV-related hospitalized ARI/LRTD cases and controls, multiplied by 100%

    Time frame: 2 years

    Adjusted for confounding factors using logistic regression. To estimate the effectiveness of ABRYSVO® against hMPV-related ARI/LRTD hospitalizations

  18. Secondary 15: ABRYSVO® VE estimates stratified by age group.

    Time frame: 2 years

    Adjusted for confounding factors using logistic regression. To estimate ABRYSVO® VE against RSV-related LRTD hospitalizations by alternative age groups 60-69 years, 70-79 years, 80 years and older

  19. Secondary 16: Among the immunocompetent, VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for RSV-related hospitalized/ED visits LRTD cases and controls, multiplied by 100%

    Time frame: 2 years

    Adjusted for confounding factors using logistic regression. To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations or ED visits (without subsequent hospitalization) among the immunocompetent.

  20. Secondary 17: ABRYSVO® VE estimates stratified by age group

    Time frame: 2 years

    Adjusted for confounding factors using logistic regression. To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations or ED visits (without subsequent hospitalization), stratified by age group (60-74 years vs 75 years and older)

  21. SSA Key Secondary 1: To estimate effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations in the 3rd season after a single dose overall and by time since vaccination up to 36 months

    Time frame: Up to 3 years

    After the 3rd RSV season, VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for RSV-related hospitalized LRTD cases and controls, overall and stratified by time since vaccination, multiplied by 100%, using LRTD hospitalization events from all seasons

  22. SSA Secondary 2: To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations or ED visits (without subsequent hospitalization) during the 2nd RSV season after a single dose

    Time frame: Up to 2 years

    Among those with 2 completed RSV seasons after vaccination with a single dose of ABRYSVO®, VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for RSV-related hospitalized/ED visit LRTD cases and controls, multiplied by 100%, using LRTD events from the 2nd season

  23. SSA Secondary 3: To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations during the 2nd RSV season after a single dose

    Time frame: Up to 2 years

    Among those with 2 completed RSV seasons after vaccination with a single dose of ABRYSVO®, VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for RSV-related hospitalized LRTD cases and controls, multiplied by 100%, using LRTD events from the 2nd season

  24. SSA Secondary 4: To estimate effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations or ED visits (without subsequent hospitalization) during the 3rd RSV season after a single dose

    Time frame: Up to 3 years

    Among those with 3 completed RSV seasons after vaccination with a single dose of ABRYSVO®, VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for RSV-related hospitalized/ED visit LRTD cases and controls, multiplied by 100%, using LRTD events from the 3rd season

  25. SSA Secondary 5: To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations or ED visits (without subsequent hospitalization) during the 4th RSV season after a single dose

    Time frame: Up to 4 years

    Among those with 4 completed RSV seasons after vaccination with a single dose of ABRYSVO®, VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for RSV-related hospitalized/ED visit LRTD cases and controls, multiplied by 100%, using LRTD events from the 4th season

  26. SSA Secondary 6: To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations during the 4th RSV season after a single dose

    Time frame: Up to 4 years

    Among those with 4 completed RSV seasons after vaccination with a single dose of ABRYSVO®, VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for RSV-related hospitalized LRTD cases and controls, multiplied by 100%, using LRTD events from the 4th season

  27. SSA Secondary 7: To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations or ED visits (without subsequent hospitalization) during the 5th RSV season after a single dose

    Time frame: Up to 5 years

    Among those with 5 completed RSV seasons after vaccination with a single dose of ABRYSVO®, VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for RSV-related hospitalized/ED visit LRTD cases and controls, multiplied by 100%, using LRTD events from the 5th season

  28. SSA Secondary 8: To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations during the 5th RSV season after a single dose

    Time frame: 5 years

    Among those with 5 completed RSV seasons after vaccination with a single dose of ABRYSVO®, VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for RSV-related hospitalized LRTD cases and controls, multiplied by 100%, using LRTD events from the 5th season

  29. SSA Secondary 9: To estimate effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations/ED visits (without subsequent hospitalization) in the second season after a single dose overall and by time since vaccination, up to 24 months

    Time frame: 2 years

    After the 2nd RSV season, VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for RSV-related hospitalized/ED visit LRTD cases and controls, overall and stratified by time since vaccination, multiplied by 100%, using LRTD hospitalization/ED events from all seasons

  30. SSA Secondary 10: To estimate effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations/ED visits (without subsequent hospitalization) in the third season after a single dose overall and by time since vaccination, up to 36 months

    Time frame: 3 years

    After the 3rd RSV season, VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for RSV-related hospitalized/ED visit LRTD cases and controls, overall and stratified by time since vaccination, multiplied by 100%, using LRTD hospitalization/ED events from all seasons

  31. SSA Secondary 11: To estimate effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations/ED visits (without subsequent hospitalization) in the fourth season after a single dose overall and by time since vaccination, up to 48 months

    Time frame: 4 years

    After the 4th RSV season, VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for RSV-related hospitalized/ED visit LRTD cases and controls, overall and stratified by time since vaccination, multiplied by 100%, using LRTD hospitalization/ED events from all seasons

  32. SSA Secondary 12: To estimate effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations/ED visits (without subsequent hospitalization) in the 5th season after a single dose overall and by time since vaccination, up to 60 months

    Time frame: 5 years

    After the 5th RSV season, VE calculated as 1 minus the OR comparing the odds of being vaccinated with ABRYSVO® for RSV-related hospitalized/ED visit LRTD cases and controls, overall and stratified by time since vaccination, multiplied by 100%, using LRTD hospitalization/ED events from all seasons

  33. SSB Primary: To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations after revaccination among those with 2 vs 0 dose of ABRYSVO®, in the first season after revaccination

    Time frame: 1 year

    VE calculated as 1 minus the OR comparing the odds of being vaccinated with two doses of ABRYSVO® vs not vaccinated with any dose of ABRYSVO® for RSV-related hospitalized LRTD cases and controls, multiplied by 100%, using events from the first season after the 2nd dose

  34. SSB Secondary 1: To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations or ED events (without subsequent hospitalization) after revaccination among those with 2 vs 0 dose of ABRYSVO®, in the first season after revaccination

    Time frame: 1 year

    VE calculated as 1 minus the OR comparing the odds of being vaccinated with two doses of ABRYSVO® vs not vaccinated with any dose of ABRYSVO® for RSV-related hospitalized/ED visit LRTD cases and controls, multiplied by 100%, using events from the first season after the 2nd dose

  35. SSB Secondary 2: To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations after revaccination among those with 2 vs 1 dose of ABRYSVO®, in the first season after revaccination

    Time frame: 2 years

    VE calculated as 1 minus the OR comparing the odds of being vaccinated with two doses of ABRYSVO® vs being vaccinated with one dose of ABRYSVO® for RSV-related hospitalized LRTD cases and controls, multiplied by 100%, using events from the first season after the 1st and 2nd dose

  36. SSB Secondary 3: To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations or ED events (without subsequent hospitalization) after revaccination among those with 2 vs 1 dose of ABRYSVO®, in the first season after revaccination

    Time frame: 2 years

    VE calculated as 1 minus the OR comparing the odds of being vaccinated with two doses of ABRYSVO® vs being vaccinated with one dose of ABRYSVO® for RSV-related hospitalized/ED visit LRTD cases and controls, multiplied by 100%, using events from the first season after the 1st and 2nd dose

  37. SSB Secondary 4: To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations after revaccination among those with 2 vs 0 dose of ABRYSVO®, in the second season after revaccination

    Time frame: 2 years

    VE calculated as 1 minus the OR comparing the odds of being vaccinated with two doses of ABRYSVO® vs not vaccinated with any dose of ABRYSVO® for RSV-related hospitalized LRTD cases and controls, multiplied by 100%, using events from the second season after the 2nd dose

  38. SSB Secondary 5: To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations or ED events (without subsequent hospitalization) after revaccination among those with 2 vs 0 dose of ABRYSVO®, in the second season after revaccination

    Time frame: 2 years

    VE calculated as 1 minus the OR comparing the odds of being vaccinated with two doses of ABRYSVO® vs not vaccinated with any dose of ABRYSVO® for RSV-related hospitalized/ED visit LRTD cases and controls, multiplied by 100%, using events from the second season after the 2nd dose

  39. SSB Secondary 6: To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations after revaccination among those with 2 vs 1 dose of ABRYSVO®, in the second season after revaccination

    Time frame: 2 years

    VE calculated as 1 minus the OR comparing the odds of being vaccinated with two doses of ABRYSVO® vs being vaccinated with one dose of ABRYSVO® for RSV-related hospitalized LRTD cases and controls, multiplied by 100%, using events from the second season after the 1st and 2nd dose

  40. SSB Secondary 7: To estimate the effectiveness of ABRYSVO® against RSV-related LRTD hospitalizations or ED events (without subsequent hospitalization) after revaccination among those with 2 vs 1 dose of ABRYSVO®, in the second season after revaccination

    Time frame: 2 years

    VE calculated as 1 minus the OR comparing the odds of being vaccinated with two doses of ABRYSVO® vs being vaccinated with one dose of ABRYSVO® for RSV-related hospitalized/ED visit LRTD cases and controls, multiplied by 100%, using events from the second season after the 1st and 2nd dose

Sponsors and collaborators

Lead sponsor

Pfizer

Industry

Collaborators

  • Kaiser Permanente

Registry information

Official study title

RETROSPECTIVE STUDY EVALUATING ABRYSVO® VACCINE EFFECTIVENESS AGAINST SEVERE LOWER RESPIRATORY TRACT DISEASE IN OLDER ADULTS

Important dates

Study start
2023
Primary completion
2029
Study completion
2029
First posted
Oct 11, 2023
Registry last updated
May 11, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

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This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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