SIDE EFFECTS
Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a vaccine cannot be directly compared to rates in the clinical trials of another vaccine and may not reflect the rates observed in practice.
The clinical development program for ERVEBO included clinical studies conducted in North America, Europe and Africa, in which a total of 15,399 adults received a dose of ERVEBO. The total number of subjects vaccinated with ERVEBO in double-blind, placebo-controlled trials was 1,712 and in open label trials was 13,687.
In Study 1 (NCT02344407), conducted in Liberia (N=1,000), subjects were randomized 1:1 to receive ERVEBO or saline placebo. Subjects were assessed at Week 1 and Month 1 postvaccination for solicited local and systemic reactions. In a subset of subjects (n=201), joint symptoms and signs were also solicited during a Week 2 visit. Memory aids were not used and postvaccination temperatures were measured only at study visits. Unsolicited adverse events were collected through Month 1 postvaccination. The median age of subjects was 29 years, 63.6% were male and 100% were Black. Serious adverse events were monitored through 1 year postvaccination.
In Study 2 (NCT02503202), conducted in the United States, Canada and Spain (N=1,197), subjects were randomized to receive ERVEBO (n=1,061) or saline placebo (n=133). Subjects used a memory aid to record solicited local reactions from Days 1 to 5 postvaccination, and daily temperature measurements and solicited joint and skin events from Days 1 to 42 postvaccination. Unsolicited adverse reactions were collected through Day 42 postvaccination. The median age of subjects was 42 years; 46.8% were male; 67.9% were White, 29.2% were Black or African American, 1.4% were Multi-racial, 0.8% were Asian, 0.4% were American Indian or Alaska Native, and 0.3% were Native Hawaiian or Pacific Islander; 14.5% were Hispanic or Latino. Serious adverse events were monitored through 6 months postvaccination and a subset of subjects (n=511) were monitored through 24 months postvaccination.
In Study 3 (Pan African Clinical Trials Registry, PACTR201503001057193), an open-label clusterrandomized study conducted in the Republic of Guinea, 5,643 adult subjects received a dose of ERVEBO. The median age of vaccinated subjects was 37 years, 68% were male and 100% were Black.
Serious adverse events were monitored through 84 days postvaccination.
In Study 4 (NCT02378753), a randomized open-label study conducted in Sierra Leone, 7,998 adult subjects received a dose of ERVEBO. The median age of subjects was 31 years, 63% were male; 99.8% were Black and 0.2% collectively were Multi-racial, Asian or White. Serious adverse events were monitored through 180 days postvaccination.
Eight additional studies (NCT02269423, NCT02280408, NCT02374385, NCT02314923, NCT02287480, NCT02283099, NCT02296983) contributed to the assessment of serious adverse reactions.
Adverse Reactions
Table 1 presents the proportion of subjects reporting solicited adverse reactions in Study 1.
Table 1: Percentage of Subjects with Solicited Local and Systemic Adverse Reactions After Vaccination (Study 1)
| ERVEBO (%) | PLACEBO (%) |
Injection-site reactions* | N= 500 | N= 500 |
Injection site pain | 34.0 | 11.2 |
Local reactions (redness/swelling) | 1.8 | 0.8 |
Systemic adverse reactions† | N= 498 | N= 499 |
Headache | 36.9 | 23.2 |
Feverishness | 34.3 | 14.8 |
Muscle pain | 32.5 | 22.8 |
Fatigue | 18.5 | 13.4 |
Nausea | 8.0 | 4.4 |
Joint pain/tenderness | 7.0 | 5.8 |
Rash | 3.6 | 3.2 |
Abnormal sweating | 3.2 | 2.6 |
Arthropathy (joint redness/warmth)‡ | 0.6 | 0.2 |
Joint swelling‡ | 0.4 | 0.4 |
Joint stiffness‡ | 0.4 | 0.2 |
* Adverse reactions were solicited at 30 minutes, Week 1 and Month 1 postvaccination. † Adverse reactions were solicited at Week 1 and Month 1 postvaccination. ‡ In a subset of subjects (n=201), joint symptoms and signs were also solicited during a Week 2 visit. |
In Study 1, 56.4% of subjects reported at least one of the solicited systemic adverse reactions listed in Table 1 within seven days after vaccination. With the exception of one subject who reported events of moderate intensity (causing greater than minimal interference with daily activity), all others reported events of mild intensity (causing no or minimal interference with daily activity).
Table 2 presents the proportion of subjects reporting solicited adverse reactions in Study 2.
Table 2: Percentage of Subjects with Solicited Local and Systemic Adverse Reactions After Vaccination (Study 2)
| ERVEBO (%) | Placebo (%) |
Injection-site reactions* | N= 1051 | N= 133 |
Injection-site pain | 69.5 | 12.8 |
Injection-site swelling | 16.5 | 3.0 |
Injection-site redness | 11.9 | 1.5 |
Systemic adverse reactions† | N= 1051 | N= 133 |
Joint pain | 17.9 | 3.0 |
Arthritis (composite term)‡ | 4.7 | 0.0 |
Rash (composite term)§ | 3.8 | 1.5 |
Vesicular lesions¶ | 1.5 | 0.0 |
* Adverse reactions were solicited Days 1 to 5 postvaccination. † Adverse reactions were solicited Day 1 through Day 42 postvaccination. ‡ Arthritis is a composite term that includes preferred terms of arthritis, monoarthritis, polyarthritis, osteoarthritis, joint swelling, or joint effusion. § Rash is a composite term that includes petechiae, purpura, rash, rash generalized, rash macular, rash papular and rash vesicular. ¶ Vesicular lesions include events reported as rash vesicular in the rash composite term and reported as blister. |
In Study 2, 29 subjects (2.8%) reported injection-site pain of severe intensity. Severe arthritis (arthritis and joint swelling) was reported by 8 subjects (0.8%) and severe arthralgia was reported by 14 subjects (1.3%). In this study, severe events were defined as incapacitating with inability to work or do usual activity.
Unsolicited Adverse Reactions
In Study 2, the unsolicited adverse reaction of chills was reported in 7.3% of ERVEBO recipients compared to 0% of placebo recipients. Paresthesia was reported by 1.4% of ERVEBO recipients compared to 0% of those who received placebo in this study.
Arthralgia And Arthritis
Arthralgia was reported to occur in 7% to 40% of vaccine recipients in blinded, placebo-controlled studies. Arthralgia was generally reported in the first few days following vaccination, was of mild to moderate intensity, and resolved within one week after onset. Severe arthralgia, defined as preventing daily activity, was reported in up to 3% of subjects.
Arthritis (including events of arthritis, joint effusion, joint swelling, osteoarthritis, monoarthritis or polyarthritis) was reported to occur in 0% to 24% of subjects in blinded, placebo-controlled studies in which subjects received ERVEBO or a lower dose formulation, with all but one study reporting arthritis in <5% of subjects. Most occurrences of arthritis were reported within the first few weeks following vaccination, were of mild to moderate intensity, and resolved within several weeks after onset. In one study conducted in Switzerland (Study 5, NCT02287480), 102 subjects received ERVEBO or a lower dose formulation. In this study, arthritis was reported to occur in 24% of subjects and severe arthritis, defined as preventing daily activity, in 12% of subjects. Joint effusion samples were obtained from three subjects and all three tested positive for vaccine virus RNA by RT-PCR. Of all 24 subjects with arthritis in Study 5, six subjects reported recurrent or prolonged joint symptoms lasting up to 2 years following vaccination, the longest follow-up period.
Rash
Rash was reported to occur after administration of ERVEBO in blinded, placebo-controlled studies, with all but one study reporting rash in <9% of subjects. In Study 5, rash was reported to occur in 25% (n=4) of ERVEBO recipients and 7.7% (n=1) of placebo recipients. In this study, cutaneous vasculitis was reported in two subjects who received a lower dose formulation, neither of whom had evidence of systemic vasculitis. Vesicular fluid and skin biopsy samples taken from some subjects reporting rash have tested positive for vaccine virus RNA by RT-PCR.
Decreases In Lymphocytes And Neutrophils
White blood cell counts were assessed in 697 subjects who received ERVEBO. Decreases in lymphocytes were reported in up to 85% of subjects and decreases in neutrophils were reported in up to 43% of subjects. No associated infections were reported.
Serious Adverse Reactions
Among 15,399 ERVEBO recipients, two serious adverse reactions of pyrexia were reported as vaccine-related. In addition, two serious adverse reactions of anaphylaxis were reported as vaccinerelated. None of these serious adverse reactions were fatal.
DRUG INTERACTIONS
Interference With Laboratory Tests
Following vaccination with ERVEBO, individuals may test positive for anti-Ebola glycoprotein (GP) antibody and/or Ebola GP nucleic acid or antigens. GP-based testing may have limited diagnostic value during the period of vaccine viremia, in the presence of vaccine-derived Ebola GP, and following antibody response to the vaccine [see Pharmacokinetics].