エボラワクチン（rVSV-ZEBOV）

エボラ流行地域の医療従事者、確定症例の接触者、活発なアウトブレイク地域への渡航者。

Severe allergic reaction (anaphylaxis) to a previous dose or any component (including rice protein). Acute febrile illness (defer). Pregnancy — limited data; use only when benefit clearly outweighs risk during active outbreaks. Breastfeeding — viral shedding in breast milk reported; weigh risk-benefit. Not recommended for severely immunocompromised individuals (live vaccine).

Very common (≥1/10): injection site pain (70%), headache (37%), fever (34%), fatigue (19%), myalgia (33%), arthralgia (18%), nausea (18%). Common: joint swelling (4%), rash, excessive sweating. Self-limiting arthritis reported in 4–24% (Prevail I trial). VSV viremia detectable in blood for 1–3 days post-vaccination (not associated with clinical disease). Rare: vasculitis, dermatitis.

Single 1.0 mL dose, intramuscular injection in the deltoid. No booster currently recommended (humoral response durable ≥2 years in clinical data). Administer as soon as possible when outbreak risk identified. Cold chain: store at -80°C to -60°C; stable at +2°C to +8°C for up to 14 days after thawing.

Ring vaccination study (DRC, Ebola ça Suffit! trial, Lancet 2017): 100% efficacy (95% CI 68.9–100.0%) with immediate vaccination (0 cases in vaccinated ring vs. 16 in delayed ring). Antibody response: ≥95% seroconversion at day 28. Durability: neutralizing antibodies detectable at 2 years in ≥90% of vaccinees.

Store at -80°C to -60°C (ultra-cold chain). After thawing: stable at +2°C to +8°C for up to 14 days. Do not refreeze. Protect from light. Use within 4 hours after removal from cold chain at room temperature.

Do not co-administer with other live vaccines unless data supports it — standard spacing (same day or ≥28 days) applies. Limited data on interaction with antimalarials. Immunosuppressive therapy may reduce response (live vaccine). No formal drug interaction studies completed.

Pregnancy: limited human data. Animal studies (reproductive toxicity): no adverse fetal effects. During DRC outbreak, inadvertent vaccination of pregnant women did not show increased adverse outcomes (post-hoc analysis). Use during active outbreak when benefit outweighs risk. Breastfeeding: rVSV detected in breast milk in some recipients — consider temporary cessation (7–14 days).

Breastfeeding: Ervebo® (rVSVΔG-ZEBOV-GP) — limited data are available for lactating women. rVSV vector has been detected in breast milk of some vaccinated women, though clinical significance is uncertain. During Ebola outbreaks, the WHO recommends that the benefit of vaccination outweighs the theoretical risk to breastfed infants, given the extremely high case fatality rate. In non-outbreak settings, defer vaccination if possible until breastfeeding is completed.

Not approved for <18 years (Ervebo). Alternative: Zabdeno (Ad26.ZEBOV) + Mvabea (MVA-BN-Filo) 2-dose heterologous regimen approved in EU for ≥1 year. Limited safety data in children <2 years.

Older adults (≥65 years): Ervebo® clinical trials included limited numbers of participants aged ≥65. Ebola virus disease has a high case fatality rate across all age groups. During outbreaks, vaccination should not be withheld based on age if exposure risk exists. Immunosenescence may reduce vaccine immunogenicity in older adults, but the benefit of any protection against a highly lethal disease outweighs this concern. Ring vaccination protocols during outbreaks include all ages.

Live vaccine — contraindicated in severe immunodeficiency. Vaccine virus shedding occurs (blood 1–3 days, urine up to 14 days, saliva 7 days). Contact precautions in healthcare settings for 14 days post-vaccination. Not for individuals <18 years (Zabdeno/Mvabea 2-dose regimen available for ≥1 year in EU). Vesicular lesions at injection site possible — cover until healed.