FDA Approves Expanded Indication of Ebola Zaire Vaccine for Individuals 12 Years of Age and Older

The FDA has approved an expanded indication for Ebola Zaire Vaccine, Live (Ervebo; Merck) to include individuals 12 months of age and older.¹ The vaccine, which was initially approved in 2019 for use in those 18 years of age and older, can now be administered to protect against the disease caused by Zaire ebolavirus in a younger patient population.

“Ebola virus disease is contagious and potentially deadly in both children and adults. We’re proud of the approval of Ervebo for the prevention of disease caused by Zaire ebolavirus in children as young as 12 months old, which is another milestone in our continued commitment to help address the global health threat caused by Zaire ebolavirus,” said Eliav Barr, MD, senior vice president, head of global clinical development and chief medical officer, Merck Research Laboratories, in a press release.¹

Merck noted that Ervebo does not protect against other species of Ebolavirus or Marburgvirus. Ervebo is a live, recombinant vaccine that targets the glycoprotein envelope of Zaire ebolavirus. The duration of protection once the vaccine has been given is currently unknown;² however, Ervebo was found to be 100% effective after vaccination in preventing the onset of symptoms after more than 10 days.³

The efficacy of Ervebo if administered concurrently with antiviral medication, immune globulin (IG), and/or blood or plasma transfusions is also unknown. Ervebo is contraindicated for those with a history of a severe allergic reaction, such as anaphylaxis, to any component of the vaccine, including rice protein.¹

In clinical trials, 18,616 were administered at least 1 dose of Ervebo, which led to 2 reports of anaphylaxis.¹ Those administered the vaccine should be monitored for signs and symptoms of hypersensitivity reactions, according to Merck.¹ They added that appropriate medical treatment and supervision should be available if an anaphylactic event occurs post administration of Ervebo.

In terms of safety, during double-blind, placebo-controlled trials, the most common injection-site adverse events (AEs) by those administered Ervebo in Study 1 (N=500) were injection-site pain (34.0%) and redness and swelling (2%), whereas in Study 2 (N=1051), the most common injection-site AEs were injection-site pain (70.0%), swelling (17%), and redness (12%).⁴

The most common systemic AEs that occurred in Study 1 (N=498) were headache (37%), fever (34%), muscle pain (33%), fatigue (19%), nausea (8%), joint pain/tenderness (7%), rash (4%), and abnormal sweating (3%). The most common systemic AEs in Study 2 (N=1051) were joint pain (18%), arthritis (5%), rash (4%), and vesicular lesions (2%).⁴

Further, arthralgia occurred in 7% to 40% of vaccine recipients during blinded, placebo-controlled studies and severe arthralgia was reported in approximately 3% of subjects.

Skin rash was reported in all but 1 study that reported rash in <9% of subjects. In Study 5, rash occurred in 25% (N=4) of those administered Ervebo vs 7.7% (N=1) of placebo recipients. Reduced lymphocytes were observed in approximately 85% of those administered Ervebo and reduced neutrophils were observed in approximately 43%.⁴

Among 15,399 individuals administered Ervebo, there were 2 serious AEs of pyrexia identified as vaccine-related. Further, 2 serious AEs of anaphylaxis were identified as vaccine-related, but none of the serious AEs were fatal.⁴

References

1. U.S. FDA Approves Merck’s ERVEBO (Ebola Zaire Vaccine, Live) for Use in Children 12 Months of Age and Older. Merck. News release. August 3, 2023. https://www.merck.com/news/u-s-fda-approves-mercks-ervebo-ebola-zaire-vaccine-live-for-use-in-children-12-months-of-age-and-older/

2. Ervebo. Prescribing Information. Merck & Co, Inc; 2019. Accessed August 3, 2023. https://www.fda.gov/media/133748/download.

3. First FDA-approved vaccine for the prevention of Ebola virus disease, marking a critical milestone in public health preparedness and response. News release. FDA. December 19, 2019. https://www.fda. gov/news-events/press-announcements/first-fda-approved-vaccine-prevention-ebola- virus-disease-marking-critical-milestone-public-health.

4. Merck Announces FDA Approval for ERVEBO® (Ebola Zaire Vaccine, Live). Merck. News release. https://www.merck.com/news/merck-announces-fda-approval-for-ervebo-ebola-zaire-vaccine-live/