Janssen’s Ebola Vaccine Added To Fight Against African Outbreak
Executive Summary
People at risk of contracting the Ebola virus in the latest outbreak in the Democractic Republic of Congo are to have another vaccination option in the form of Janssen’s experimental prime-boost vaccine regimen, Ad26.ZEBOV/MVA-BN.
A second experimental vaccine against the Ebola virus is to be introduced in the Democratic Republic of Congo, which is currently experiencing the world’s second-largest Ebola outbreak on record, with more than 2,000 lives lost and some 3,000 infections confirmed since the latest epidemic was declared in August last year.
The new vaccine, which is manufactured by Janssen, will be given in two doses 56 days apart, targeted at at-risk populations in areas that do not have active Ebola transmission, according to the World Health Organization.
It will complement Merck Sharp & Dohme’s V920 (rVSV-ZEBOV) vaccine, which has been used on an experimental basis in the DRC since mid-2018. V920 has “proven highly effective and safe” and will continue to be given to all people at high risk of infection, the WHO said. (Also see "Merck's View On The Challenges Of Ebola Vaccination In The DRC" - Pink Sheet, 13 Nov, 2018.)
Dr Matshidiso Moeti, the WHO’s regional director for Africa, said that evaluating the use of a second vaccine in DRC would “help ensure that we have potentially an additional tool to prevent the expansion of the outbreak and also a potential tool to protect populations before outbreaks hit areas at risk.”
More than 223,000 people have received Merck’s V920 vaccine during the current outbreak, according to the WHO. It says there are now enough vaccine doses on the ground to meet current needs, “with WHO logisticians ensuring a minimum supply of 10,000 doses at all times.” Given the number of cases currently being reported and the doses required to vaccinate around each case, available doses of Merck’s V920 vaccine are considered sufficient, according to the organization.
The company has provided the WHO with 245,000 doses of its vaccine for DRC and neighboring countries and has built up a stockpile of 190,000 doses that are ready to send to DRC. It also aims to release 650,000 doses over the next six to 18 months under its replenishment strategy, the WHO added. Under the current recommendations from the WHO’s Strategic Advisory Group of Experts (SAGE), this means that there are 390,000 doses currently and additional 1.3 million doses will be available.
Still, the WHO thinks it wise to have another arrow in its Ebola quiver. “The Merck vaccine is highly efficacious, and we’ll soon have a second vaccine to increase the number of those being protected against the virus,” said WHO director-general Tedros Adhanom Ghebreyesus.
The Second Vaccine
The introduction of a second vaccine was raised by the SAGE in May, when it met to discuss a revised Ebola vaccination strategy for the DRC to include a second and third barrier of immunized individuals around each case of confirmed disease (“ring vaccination”).
The group recommended that an alternative vaccine should be used to vaccinate those at lower risk in affected health areas. It reviewed data on two products: Janssen’s Ad26.ZEBOV/MVA-BN and another vaccine, Ad5-EBOV, from the CanSino-Beijing Institute of Biotechnology. “SAGE recommends that these lower risk populations would be vaccinated with the J&J vaccine with informed consent,” it announced.
The Janssen product is a prime-boost vaccine regimen consisting of two parts: Janssen’s adenovirus type 26 vector encoding Ebola glycoprotein, and a modified vaccinia Ankara vector vaccine from Bavarian Nordic.
Noting that prime-boost vaccination is an established approach for preventing other infectious diseases, Janssen said the available clinical data on its vaccine show that the two-dose regimen “induces a robust and durable immune response, and is well tolerated.”
The vaccine was developed in a collaborative research program with the US National Institutes of Health and received direct funding and preclinical services from the National Institute of Allergy and Infectious Diseases. The company has built up a stockpile of up to 1.5 million investigational vaccine regimens for potential use in public health emergencies.
Trials of the Janssen product are due to begin in the central African country in October. SAGE said in its recommendations that proposed studies should be “scientifically and epidemiologically justified, have appropriate approvals including from all relevant national and other regulatory and ethics authorities, and have defined endpoints suitable for licensure.”
The WHO said that a group led by the Coalition for Epidemic Preparedness Innovations (CEPI) and the London School of Hygiene and Tropical Medicine (LSHTM), along with other partners, was at “an advanced stage towards the deployment and assessment of this vaccine” in DRC.
The LSHTM also reported in August that the Janssen vaccine regimen had entered a two-year trial among health care and frontline workers in neighboring Uganda. The ZEBOVAC trial, which is funded by CEPI and sponsored by the LSHTM, will enrol 800 people in the west of the country, which borders on DRC. Its aim is to provide additional information on the vaccine and evaluate its safety and ability to provoke an immune response.
The LSHTM said that the vaccine had now been tested in more than 6,000 people in Europe, the US and Africa. It has shown “outstanding safety and immunogenicity in humans and is highly protective against Ebola challenge in non-human primates,” it declared.
Approval Progress
Neither of the vaccines yet has a marketing authorization. In the US, where V920 has breakthrough status, the Food and Drug Administration accepted a "rolling submission" in November 2018 and earlier this month set a 14 March 2020 user fee date. (Also see "Keeping Track: A Duo Of RTOR Approvals, Thumbs Up For First Oral GLP-1 Treatment, And First Ebola Vaccine Nears US Market" - Pink Sheet, 21 Sep, 2019.) In the EU the vaccine has PRIME (priority medicines) status and is undergoing an accelerated assessment, having been submitted to the EMA in March this year.
Meanwhile, Janssen has also applied to the EMA for accelerated assessment of its two-part vaccine regimen. It told the Pink Sheet last week that it intended to submit marketing authorization applications to the agency before the end of this year. (Also see "Vertex Among Four Hopefuls Seeking EMA's Elusive Speedy Review" - Pink Sheet, 18 Sep, 2019.)
In May this year, the WHO published details of the coordinating role it intends to play in the licensing and roll-out of V920. (Also see "WHO To Facilitate Rapid Roll Out Of Merck's Ebola Vaccine In Africa" - Pink Sheet, 28 May, 2019.)