key: cord-285128-48l1w65p authors: Custers, Jerome; Kim, Denny; Leyssen, Maarten; Gurwith, Marc; Tomaka, Frank; Robertson, James; Heijnen, Esther; Condit, Richard; Shukarev, Georgi; Heerwegh, Dirk; van Heesbeen, Roy; Schuitemaker, Hanneke; Douoguih, Macaya; Evans, Eric; Smith, Emily R.; Chen, Robert T. title: Vaccines based on replication incompetent Ad26 viral vectors: standardized template with key considerations for a risk/benefit assessment date: 2020-10-03 journal: Vaccine DOI: 10.1016/j.vaccine.2020.09.018 sha: doc_id: 285128 cord_uid: 48l1w65p Replication-incompetent adenoviral vectors have been under investigation as a platform to carry a variety of transgenes, and express various antigens as a basis for preventive or therapeutic vaccine development. A replication incompetent adenoviral vector based on human adenovirus type 26 (Ad26) has been evaluated in several clinical trials. The Brighton Collaboration Viral Vector Vaccines Safety Working Group (V3SWG) was formed to evaluate the safety and features of recombinant viral vector vaccines. This paper reviews the biological features of the Ad26 vectors, including tabulation of safety and risk assessment characteristics of Ad26 vector-based vaccines. Substantial information on immunogenicity, clinical safety, biological characteristics and manufacturing are reported. In the Ad26 vector, deletion of the E1 gene, rendering the vector replication incompetent and providing space for transgene insertion, is combined with additional genetic engineering for vaccine manufacturability and transgene expression optimization. These vaccines are manufactured using the E1-complementing PER.C6® cell line, a continuous, human cell-line that can be cultured in serum-free medium in a suspension to high cell densities, providing an effective and flexible system for high-yield manufacturing. Ad26 vector vaccines have favorable thermostability profiles, compatible with vaccine supply chains. Safety data are compiled in the Ad26 vaccine safety database version 4.0, with unblinded data from 23 ongoing and completed clinical studies for a total of 3912 participants in Ebola, HIV, Malaria, RSV and Filovirus Ad26-based vaccine programs. Overall, all Ad26-based vaccines have been well tolerated, with no significant safety issues identified from the available data in the current Ad26 vaccine safety database. Evaluation of Ad26-based vaccines to further characterize the safety profile is continuing, with more than 90,000 participants vaccinated as of 1st July 2020 (cut-off date). Extensive evaluation of immunogenicity in humans shows strong and durable humoral and cellular immune responses. Clinical trials have not shown meaningful impact of pre-existing immunity to Ad26 on vaccine immunogenicity, even in the presence of Ad26 neutralizing antibody titers or Ad26-targeting T cell responses at baseline. The first vaccine, against Ebola virus, that makes use of the Ad26 vector, received marketing authorization from EC on 1st July 2020, as part of the Ad26.ZEBOV, MVA BN Filo vaccine regimen. New developments based on the Ad26 vector are underway, including a COVID-19 vaccine, which is currently in clinical evaluation. The Brighton Collaboration (www.brightoncollaboration.org) V3SWG is an established collaboration who aim to enhance the science of vaccine safety research (http://cms.brightoncollaboration.org: 8080/public/what-we-do/setting-standards/casedefinitions/process). The Brighton V3SWG uses a standardized template to describe the key characteristics of novel vaccine vectors, compiled from the latest research, to facilitate scientific discourse among key stakeholders (1). The adenovirus type 26 (Ad26) wild type virus was first isolated in 1956 from an anal specimen of a 9-month-old male child (2) . As described in that study, 4 different isolates were obtained from anal and throat swabs from different children, some of whom experienced mild selflimiting enteric infections. Although, none of the illnesses could etiologically be associated with the isolated adenoviruses, it suggests that wild type Ad26 can, presumably, cause asymptomatic or minor illness (2) . Human Ad26 has been considered to be a low-prevalent adenovirus due to the low frequency of Ad26 neutralizing antibodies in various populations compared with human adenovirus type 5. For example, a seroprevalence study of the 51 human adenovirus serotypes known at the time showed that several serotypes from particularly subgroups B and D, including Ad26, were rare in a Belgian population (3) , suggesting that vectors (rAd) derived from these serotypes might be useful alternatives to Ad5-based vectors for vaccine development, since for Ad5-based vectors it was shown that their high prevalence hampered their clinical use (4) (5) (6) (7) (8) . More extensive seroprevalence and immunogenicity studies showed that while all of these vectors exhibited low seroprevalence, Ad26-based vaccine candidates were the most immunogenic in animals (9) . Further studies have shown that, depending on geographical location, 10%-90% of people tested have neutralizing antibodies against Ad26. However, neutralization titers are low to intermediate compared with those observed for other adenovirus types (10-13). Adenovirus genomes are linear, non-segmented double-stranded DNA molecules with inverted terminal repeat (ITR) sequences at each end. The vector system for replication-incompetent Ad26 vaccine vectors consists of an adaptor plasmid and a cosmid (9) . The adaptor plasmid contains the left end of the genome containing the left ITR and the packaging signal. It also contains a transgene expression cassette in place of the E1 region and a ~2.5 kb fragment downstream of the E1 region to enable homologous recombination with the cosmid. The cosmid contains the majority of the Ad genome, spanning from the pIX sequence to the right ITR, with a deletion of the E3 region and a modified E4 open reading frame 6 (E4orf6). Transfection into a suitable packaging cell line (HEK293 cells, PER.C6 ® cells) and subsequent homologous recombination of the adaptor plasmid and cosmid results in the generation of a replicationincompetent E1/E3-deleted Ad26 vector. Packaging cell lines like the HEK293 and PER.C6 ® cell lines contain the E1 region of adenovirus serotype 5 (Ad5). Because within the adenoviral life cycle, E1 protein 55K and E4 protein Orf6 form a complex that is pivotal for high-level lategene expression, the E4-Orf6 sequence of Ad26 is replaced by the corresponding sequence from Ad5 in the vector. This modification has previously been shown to be necessary to allow for the efficient production of rAd35 virus on Ad5 E1-complementing cells (14) . Finally, compensation for the loss of E3 is not needed since the E3 proteins are not essential for adenoviral growth in vitro but are involved in down regulating cellular immunological response mechanisms in an attempt of the adenovirus to escape the host immune system (15) . Most adenovirus serotypes use the coxsackievirus-adenovirus receptor for attachment to the target cell (16, 17) . In contrast, Ad26 has been reported to utilize CD46 as its primary cellular receptor (9, 18) , but more recent reports indicated only a limited interaction between Ad26 and CD46, even showing evidence of a role for αvβ3 integrin for efficient transduction of epithelial cells, or interaction with sialic acid (19, 20) . These data suggest that receptor usage by Ad26 might be host cell-type dependent in vitro (19, 20) . Target cells in vivo in the natural host are not known, but Ad26 virus can infect a variety of cell types in vitro. Detailed studies dissecting the attachment, internalization and intracellular trafficking of adenoviral vectors have shown that Ad26, amongst others, accumulate in the late endosome to a larger extent and trigger innate immune pathways differentially compared with Ad5-based vectors (21) . Whether and how these differences may translate into differential profiles of adaptive immunity against the vaccine antigen is not known. Ad26 vector-based vaccines are manufactured using the E1-complementing PER.C6 ® cell line, a continuous, human cell line capable of supporting the manufacturing of replication incompetent adenoviral vectors (22) . One of the key strengths of this cell platform is that the cells can grow in suspension in serum-free media to very high cell densities. Cell counts of 100 million cells/mL, with a high percentage of viable cells, can be reached within 10 days of cell culture. Janssen has taken advantage of the ability to grow the PER.C6 ® cell line at high cell densities in a so called "intensified process". Cell-specific yields are in the same range as is generally achieved with other Adenoviral vectors and E1-complementing cell lines, therefore, due to the higher cell densities yields per volume unit are higher. The complete manufacturing process has now been scaled up to 1,000 L allowing manufacturing at a commercial scale. While lyophilized vaccines are generally more heat-stable than non-lyophilized alternatives (23), liquid vaccine formulations may have several advantages over lyophilized vaccines, including ease of manufacture, packaging, and simple administration procedures (24) . For Ad26-based vectors, progress in formulation development has allowed for long-term storage of product at 2-8°C, enabling product distribution through existing vaccine supply chains. Assessments of robustness during storage, handling and distribution conditions have shown that recombinant Ad26 vectors can be maintained stable under frozen conditions or at 2-8°C, and, furthermore, showed to be stable in-use with a syringe/needle, also when subjected to agitation or temperature excursions (25). Ad26-based vaccines have been extensively tested in completed and ongoing clinical studies from multiple clinical programs ( Figure 1) The The Brighton Collaboration V3SWG authors declare that they have no known competing Ad26 was rendered replication incompetent by deletion of early region 1 (ΔE1). A partial deletion of non-essential early region 3 (ΔE3) was made to create enough space in the genome for the transgene expression cassette (inserted in E1 region) also further attenuating the vector. • In gene therapy experiments n.a. • In any other special populations n.a. The Ad26 vector is replication incompetent in non-E1 complementing cells and, as such, will be replication incompetent when administered to nonhuman species. In addition, insertion of foreign antigens is not expected to change the host-range of the vaccine vector. What is the risk of reversion to virulence or recombination with wild type virus or other agents? Recombination of Ad26 vaccine vectors with wildtype viruses would require sequence homology and presence of both the genome of Ad26 vaccine vectors and wild-type adenoviruses to be present in the same cell(s). Nonclinical biodistribution studies show that adenoviral vector DNA of Ad26 vaccine vectors did not distribute widely, as the vector DNA was primarily detected at the site of administration in the muscle, the draining lymph nodes and, to a lesser extent, to the spleen. DNA of intramuscularly administered replicationincompetent Ad vaccine vector and wild-type adenovirus DNA are unlikely to co-locate in the same body compartments. In the unlikely event that recombination occurs between vaccine vector and wild-type adenoviruses, the virulence can maximally be 22 equal to the wild-type adenovirus already present in the tissue. The majority of the theoretical homologous recombination products are replication incompetent or attenuated forms of the Ad26. Reversion of Ad26 virulence by recombination is therefore highly unlikely. Furthermore, reversion of virulence due to nucleotide mutations is impossible since deletion of the E1 gene from the Ad26 vector cannot be restored by random mutations and or indels. Recombination with other viruses has not been described and is considered highly unlikely due to the limited biodistribution and absence of sequence homology and replication. The dsDNA genome of Ad26 virus is relatively stable when compared to RNA viruses. Genetic stability of the vector is confirmed during manufacturing and upscaling by extended passaging and/or genetic stability testing. (53) What is the potential for shedding and transmission to humans or other species? Vector shedding is limited and transmission of the Ad26 vector is highly 23 unlikely in view of: i) the vector is replicationincompetent, and thus, allows only for one-time transduction of the target cell, ii) the limited shedding as observed in clinical studies, iii) the limited biodistribution profile as observed in nonclinical studies, and iv) the very low probability of regaining replication-competence through recombination with co-infecting wild-type virus. Biodistribution studies in rabbits have shown that vector DNA is not widely distributed, and clearance has been observed indicating that the vector is unlikely to persist in the tissues following intramuscular injection. In nature, wild-type adenovirus is known to be able to cause persistent infections. Whether the Ad26 vector can persist for longer time in humans is unknown. This will depend on the design of the antigen and the antigenic diversity of the pathogen. The transgene is inserted in the E1 region at the site of the E1-deletion. The E1 region is deleted to render the vector replication incompetent and together with a deletion in the E3 region provide space for (9) 26 insertion of a transgene expression cassette. 5.6. How is the transgene expression controlled (transcriptional promoters, etc.)? In general, expression of the antigen is regulated using the long human CMV immediate-early promoter, which is thought to be active in most mammalian cells, and an SV40-derived polyadenylation sequence. The expressed antigen is not part of the viral particle and, as such, it is not expected that the phenotype of the vector nor the pathogenicity (the vector is replication incompetent) of the vector are altered. 5.8. Is the vaccine replicationcompetent in humans or other species? The Ad26 vector is replication incompetent. 5.9. What is the risk of reversion to virulence or recombination with wild type or other agents? See 4.5. Genetic stability of the vaccine vector is confirmed during manufacturing and upscaling by extended passaging and genetic stability testing. 5.11. What is the potential for shedding and transmission to humans or other species? See 4.7. The vaccine is replication incompetent and is unable to establish a productive infection. Persistence/latency is not expected as the vaccine misses the E1 and E3 genes that code for proteins involved in countering the host immune system. In addition, nonclinicalbiodistribution studies of the vaccine have shown that the Ad26 vaccine vector is cleared from vector positive tissues (see 6.7.). 5.13. Does the vaccine replicate in the nucleus? The vaccine is replication incompetent. The vector genome (linear ds-DNA) travels to the nucleus of the host cell where antigen expression occurs, in the absence of vaccine vector replication. 5.14. What is the risk of integration into the human genome? See 3.6. (42-45) 5.15. List any disease manifestations caused by the vaccine in humans, the strength of evidence, severity, and duration of disease for the following categories: n.a. • In healthy people n.a. • In immunocompromised people n.a. • In neonates, infants, children n.a. • During pregnancy and in the unborn n.a. • In any other special populations n.a. 28 See 3.8. The Ad26 vector is expected to have the same cell tropism as the wild-type Ad26 virus. (9, (18) (19) (20) 5.17. What is known about the mechanisms of immunity to the vaccine? In general, the immune responses to the vaccine antigen encoded by the vector are characterized by a rapid increase in binding and in most cases neutralizing antibodies. In addition, induction of nonneutralizing, functional antibodies with effector functions, like antibodydependent cellular phagocytosis (ADCP) and antibody-dependent cellular cytotoxicity (ADCC), have been observed. Induction of cellular immunity (both CD4+ and CD8+ T-cells) is also observed. 19 . What is known about the effect of pre-existing immunity, including both natural immunity and repeat administration of the vector or the vaccine, on 'take', safety or efficacy in any animal model or human studies using this vector? Data acquired to date, in more than 6,000 vaccinated human participants, have not revealed impact of preexisting vector immunity on the vaccine insert specific humoral or cellular (31, 32) 29 response. Repeated administration with the Ad26 vector leads to an increase in antigen specific humoral responses and a maintenance of cellular responses. With more than 90,000 participants vaccinated overall, no safety issues have been identified. . 5.20. Is the vaccine transmissible in humans or other species (including arthropods) and/or stable in the environment? The vaccine is replication incompetent, so no vaccine transmission is expected (see also 4.7.). 5.21. Are there antiviral or other treatments available for disease manifestations caused by the vaccine? The vector is replicationincompetent; thus, no disease manifestations are expected besides local and systemic reactogenicity. Therefore, there is no benefit for antiviral treatment. The Ad26 vector showed a limited distribution following intramuscular injection in rabbits and clearance of the vector was observed, indicating that the vector does not replicate and/or persist in the tissues 30 following intramuscular (IM) injection. The Ad26 vector did not induce any adverse effects in multiple GLP repeat-dose toxicity studies in rabbits (and rats), irrespective of the transgene insert used. 6.2. For replicating vectors, has a comparative virulence and viral kinetic study been conducted in permissive and susceptible species? (yes/no) If not, what species would be used for such a study? Is it feasible to conduct such a study? Not applicable, since the Ad26 vector is replication incompetent 6.3. Does an animal model relevant to assess attenuation exist? Not applicable, since the Ad26 vector is replication incompetent 6.4. Does an animal model for safety including immuno-compromised animals exist? Not applicable, since the Ad26 vector is replication incompetent 6.5. Does an animal model for reproductive toxicity exist? Not applicable, since the Ad26 vector is replication incompetent The general (repeat-dose) toxicity studies conducted with the replication incompetent Ad26 vector in rabbits (and rats) have not revealed any effects on male sex organs that would impair male fertility. In addition, the general (repeat-dose) and/or developmental and reproductive toxicity studies did not reveal any evidence of impaired female fertility nor did not indicate harmful effects with respect to reproductive toxicity in female rabbits. 6.6. Does an animal model for immunogenicity and efficacy exist? Most mammalian species studied to date have shown 31 induction of insert specific immunity after administration of Ad26based vaccines, dependent on the studied disease. Several efficacy animal models exist -the most studied animal models have been mice, rabbits, ferrets, cotton rats and several nonhuman primate (NHP) species. 6.7. Does an animal model for antibody enhanced disease or immune complex disease exist? No 6.8. What is known about biodistribution in animal models or in humans? Biodistribution studies have been conducted in rabbits. Following intramuscular administration, the Ad26 vector did not widely distribute as vector DNA was primarily detected at the site of injection, draining lymph nodes and (to a lesser extent) the spleen. Over time, the number of animals with positive tissues and/or the vector copy number present in those positive tissues declined, indicating clearance of the Ad26 vector. 6.9. What is the evidence that vector derived vaccines will generate a beneficial immune response in: • Small animal models? Mice, cotton rats, rabbits and ferrets have been shown to (9, 29, 58, 59, 62, (67) (68) (69) (70) (71) develop immune responses against a variety of vaccine inserts. • Nonhuman primates (NHP)? NHP have been shown to develop protective immune responses against a variety of vaccine inserts. (9, 18, 30, 61, 62, 64, 65, 69, 72, 73) • Overall, no safety concerns were identified in elderly after vaccination with adeno-based vaccines. (cut-off: 1 st July 2020; active only, estimate based on the study randomization ratios). No safety concerns were identified. • Pregnancy and in the unborn in humans? The most recent aggregate review of pregnancy exposure data was performed in September 2019; this analysis of the current experience with pregnancies after exposure to the Ebola candidate vaccines (Ad26.ZEBOV, Ad26.Filo) in female participants or partners of male participants did not reveal a safety concern. Serious complications or SAEs during pregnancy were reported in 20 out of a total of 66 pregnancies reported in female study participants. None of these serious complications / SAEs were considered causally associated with the study vaccines by Investigators or Low risk; pregnancy is an exclusion criterion for all Ad26-based vaccine studies except 1 study (described below). Pregnancy tests prior to vaccination and the use of adequate contraception was mandatory for all female participants of childbearing potential. Pregnant women are being enrolled in the ongoing Ebola vaccination study in DRC (DRC-EB-001/EBL3008). (75) the Company. No apparent concernable pattern of AEs is emerging from this review. No congenital malformations were reported to date in foetuses or newborns. Spontaneous abortion was the most commonly observed SAE (9 out of 66 pregnancies) with an incidence of 13.6%, which is within the range of expected spontaneous abortion rates during the first trimester of gestation, even when considering that spontaneous abortion incidences vary significantly depending on geographical areas and individual risk factors (e.g. age, previous abortions) 2 . • In any other special populations. Not applicable 8.3. What is the potential for shedding and transmission in risk groups? There is no significant risk for shedding and transmission of Ad26vectored vaccines across the risk groups (e.g. immunocompromised) who have received the vaccine vector. Also Designated V920) Recombinant Vesicular Stomatitis Virus Pseudotyped With Ebola Zaire Glycoprotein: Standardized Template With Key Considerations for a risk/benefit Assessment Four newly recognized adenoviruses Replication-deficient human adenovirus type 35 vectors for gene transfer and vaccination: efficient human cell infection and bypass of preexisting adenovirus immunity Safety and immunogenicity of a replication-incompetent adenovirus type 5 HIV-1 clade B gag/pol/nef vaccine in healthy adults vaccine-induced immunity in the test-of-concept Step Study: a case-cohort analysis Human adenovirus-specific T cells modulate HIV-specific T cell responses to an Ad5-vectored HIV-1 vaccine Decreased preexisting Ad5 capsid and Ad35 neutralizing antibodies increase HIV-1 infection risk in the Step trial independent of vaccination Phase 1 safety and immunogenicity evaluation of a multiclade HIV-1 candidate vaccine delivered by a replication-defective recombinant adenovirus vector Comparative seroprevalence and immunogenicity of six rare serotype recombinant adenovirus vaccine vectors from subgroups B and D International epidemiology of human pre-existing adenovirus (Ad) type-5, type-6, type-26 and type-36 neutralizing antibodies: correlates of high Ad5 titers and implications for potential HIV vaccine trials Neutralizing antibodies to human and simian adenoviruses in humans and New-World monkeys International seroepidemiology of adenovirus serotypes 5, 26, 35, and 48 in pediatric and adult populations Novel replication-incompetent adenoviral B-group vectors: high vector stability and yield in PER.C6 cells Functions and mechanisms of action of the adenovirus E3 proteins The coxsackievirus-adenovirus receptor protein can function as a cellular attachment protein for adenovirus serotypes from subgroups A Isolation of a common receptor for Coxsackie B viruses and adenoviruses 2 and 5 Adenovirus serotype 26 utilizes CD46 as a primary cellular receptor and only transiently activates T lymphocytes following vaccination of rhesus monkeys alphavbeta3 Integrin Is Required for Efficient Infection of Epithelial Cells with Human Adenovirus Type 26 Adenovirus serotype 26 utilises sialic acid bearing glycans as a primary cell entry receptor Late endosomal trafficking of alternative serotype adenovirus vaccine vectors augments antiviral innate immunity New helper cells and matched early region 1-deleted adenovirus vectors prevent generation of replication-competent adenoviruses Thermostability of vaccines Opportunities and challenges of developing thermostable vaccines Stability and suitability for storage and distribution of Ad26.ZEBOV/MVA-BN(R)-Filo heterologous prime-boost Ebola vaccine Innovation: Johnson & Johnson Announces Donation of up to 500,000 Regimens of Janssen's Investigational Ebola Vaccine to Support Outbreak Response in Democratic Republic of the Congo (DRC) Our Company: Johnson & Johnson Announces Commitment to Support Republic of Rwanda's Preparedness Against Ebola Outbreak European Medicines Agency. Meeting highlights from the Committee for Medicinal Products for Human Use (CHMP) Development of a replication-deficient adenoviral vector-based vaccine candidate for the interception of HPV16-and HPV18-induced infections and disease Ad26/MVA therapeutic vaccination with TLR7 stimulation in SIV-infected rhesus monkeys Evaluation of a mosaic HIV-1 vaccine in a multicentre, randomised, double-blind, placebo-controlled, phase 1/2a clinical trial (APPROACH) and in rhesus monkeys (NHP 13-19) First-in-human evaluation of the safety and immunogenicity of a recombinant adenovirus serotype Env vaccine (IPCAVD 001) Characterization of humoral and cellular immune responses elicited by a recombinant adenovirus serotype 26 HIV-1 Env vaccine in healthy adults (IPCAVD 001) Assessment of the Safety and Immunogenicity of 2 Novel Vaccine Platforms for HIV-1 Prevention: A Randomized Trial Our Efforts to Develop a Vaccine and Identify Therapies for COVID-19 Immune Responses to Novel Adenovirus Type 26 and Modified Vaccinia Virus Ankara-Vectored Ebola Vaccines at 1 Year Safety and Immunogenicity of Novel Adenovirus Type 26-and Modified Vaccinia Ankara-Vectored Ebola Vaccines: A Randomized Clinical Trial Induction of HIV-1-specific mucosal immune responses following intramuscular recombinant adenovirus serotype 26 HIV-1 vaccination of humans Safety and preliminary efficacy of CS-based recombinant adenoviral serotype 35 and serotype 26 malaria vaccine candidates in prime-boost vaccination of healthy adults undergoing subsequent experimental P. falciparum sporozoite challenge (ABSTRACT) Adenovirus Transmission: National Center for Immunization and Respiratory Diseases, Division of Viral Diseases Perspective on Adenoviruses: Epidemiology, Pathogenicity, and Gene Therapy New insights into stability of recombinant adenovirus vector genomes in mammalian cells Progress in human gene therapy Episomal vectors for gene therapy Guideline on nonclinical testing for inadvertent germline transmission of gene transfer vectors Conjunctivitis and enteric infection with adenovirus types 26 and 27: responses to primary, secondary and reciprocal cross-challenges Acute meningoencephalitis caused by adenovirus serotype 26 Adenovirus infections in immunocompetent and immunocompromised patients Adenoviruses in the immunocompromised host Quantifying adenovirus-neutralizing antibodies by luciferase transgene detection: addressing preexisting immunity to vaccine and gene therapy vectors New drug on the horizon for treating adenovirus Division of Viral Diseases Viral mutation rates A two-dose heterologous prime-boost vaccine regimen eliciting sustained immune responses to Ebola Zaire could support a preventive strategy for future outbreaks Safety and Immunogenicity of a 2-Dose Heterologous Vaccine Regimen with Ad26 Filo Ebola Vaccines: 12-Month Data From a Phase 1 Randomized Clinical Trial in Safety and Immunogenicity of a 2-Dose Heterologous Vaccination Regimen with Ad26.ZEBOV and MVA-BN-Filo Ebola Vaccines: 12-Month Data From a Phase 1 Randomized Clinical Trial in Uganda and Tanzania Packaging capacity and stability of human adenovirus type 5 vectors Ad35 and ad26 vaccine vectors induce potent and cross-reactive antibody and T-cell responses to multiple filovirus species Recombinant low-seroprevalent adenoviral vectors Ad26 and Ad35 expressing the respiratory syncytial virus (RSV) fusion protein induce protective immunity against RSV infection in cotton rats EBOVAC-Salone: Lessons learned from implementing an Ebola vaccine trial in an Ebola-affected country Similar Epitope Specificities of IgG and IgA Antibodies Elicited by Ad26 Vector Prime, Env Protein Boost Immunizations in Rhesus Monkeys Recombinant adenovirus serotype 26 (Ad26) and Ad35 vaccine vectors bypass immunity to Ad5 and protect nonhuman primates against ebolavirus challenge Adenoviral vector type 26 encoding Zika virus (ZIKV) M-Env antigen induces humoral and cellular immune responses and protects mice and nonhuman primates against ZIKV challenge Correction: A prophylactic multivalent vaccine against different filovirus species is immunogenic and provides protection from lethal infections with Ebolavirus and Marburgvirus species in non-human primates Protective efficacy of adenovirus/protein vaccines against SIV challenges in rhesus monkeys A very strong enhancer is located upstream of an immediate early gene of human cytomegalovirus Low seroprevalent species D adenovirus vectors as influenza vaccines The Th1 immune response to Plasmodium falciparum circumsporozoite protein is boosted by adenovirus vectors 35 and 26 with a homologous insert Alternative serotype adenovirus vaccine vectors elicit memory T cells with enhanced anamnestic capacity compared to Ad5 vectors Adenovirus vectorbased prime-boost vaccination via heterologous routes induces cervicovaginal CD8(+) T cell responses against HPV16 oncoproteins Immunogenicity without Efficacy of an Adenoviral Tuberculosis Vaccine in a Stringent Mouse Model for Immunotherapy during Treatment Vaccination with adenovirus serotypes 35, 26, and 48 elicits higher levels of innate cytokine responses than adenovirus serotype 5 in rhesus monkeys Durability and correlates of vaccine protection against Zika virus in rhesus monkeys Adenoviral Vaccine Safety Database V4.0. 14 75 We thank the additional V3SWG members and participants for their support and helpful comments, and Patrick Zuber of the World Health Organization for bringing together many of the coauthors for completing the first draft of this template and for his support of the V3SWG.We would also like to thank Wouter Koudstaal (independent scientific writer) and Kerstin Luhn, ☐ The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.☒The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Jerome Custers, Maarten Leyssen, Frank Tomaka, Esther Heijnen, Georgi Shukarev, Dirk Heerwegh, Roy van Heesbeen, Hanneke Schuitemaker, and Macaya Douoguih, are current employees of Janssen Pharmaceuticals and potentially hold stock in J&J. ☒ The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.☐The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: