• Vaccine Name: Johnson & Johnson COVID-19 vaccine
• Target Pathogen: SARS-CoV-2
• Target Disease: COVID-19
• Product Name: Ad26.COV2.S
• Tradename: JNJ-78436735
• Manufacturer: Janssen Pharmaceutica
• Vaccine Ontology ID: VO_0005159
• CDC CVX code: 212
• CDC CVX description: SARS-COV-2 (COVID-19) vaccine, vector non-replicating, recombinant spike protein-Ad26, preservative free, 0.5 mL
• Type: Recombinant vector vaccine
• Status: Clinical trial
• Host Species for Licensed Use: Human
• Host Species as Laboratory Animal Model: macaques
• Antigen: S protein with tissue plasminogen activator leader sequence and two proline stabilizing mutations (Mercado et al., 2020)
• spike (S) protein gene engineering:
  • Type: Recombinant vector construction
  • Description: The S protein gene is engineered to be added to the Ad viral vaccine vector for expression (Mercado et al., 2020).
  • Detailed Gene Information: Click Here.
• Immunization Route: intranasal immunization
• Description: A recombinant viral vector virus using adenovirus serotype26 vector experssing the S protein (Mercado et al., 2020).
  Ad26.COV2.S is currently undergoing a Phase III clinical trial: (NCT04505722)

Macaque Response

• Vaccination Protocol: Immunized vector with Ad26 vaccine with immunization of 10^11 viral particles by the intramuscular route on week 0.
• Immune Response: Liver titer neutralizing antibodies present (median 113; range 53-233) (Mercado et al., 2020). Presence of INF-gamma response but minimal to no IL-4 response (Mercado et al., 2020). NAb titers as measured by both assays were observed in the majority of vaccinated animals at week 2 and generally increased by week 4. The Ad26-S.PP vaccine elicited the highest pseudovirus NAb titers (median 408; range 208–643) and live virus NAb titers (median 113; range 53–233) at week 4. The Ad26-S.PP vaccine also induced detectable S-specific IgG and IgA responses in bronchoalveolar lavage (BAL). Cellular immune responses were induced in 30 of 32 vaccinated animals at week 4. A single immunization of 1011 vp Ad26-S.PP elicited consistent IFN-γ ELISPOT responses but minimal to no IL-4 ELISPOT responses, suggesting induction of Th1-biased responses. (Mercado et al., 2020)
• Challenge Protocol: Week 6 after initial vaccination had each animal exposed to 1^4 TCID50 SARS-CoV2 vy the intranasal and intratracheal routes (Mercado et al., 2020).
• Efficacy: Complete protection called due to no detecable vius in bronchoalveolar lavage with limit of detectin of 1.69log10sgRNAcopies/Ml (Mercado et al., 2020). Macaques that were treated with Ad26-S.PP had no detectable virus in BAL samples. Only one of the macaques that received the Ad26-S.PP vaccine showed a low amount of virus in nasal swabs. All vaccinated macaques showed no detectable infectious virus in nasal swabs by plaque-forming unit (PFU) assays. A comparison of peak viral loads in the vaccinated macaques suggested that protection in BAL samples was generally more robust than in nasal swabs (Fig. 5). The Ad26-S.PP vaccine provided complete protection in both the lower and upper respiratory tract with the exception of one macaque that showed a low amount of virus in nasal swabs, and resulted in greater than 3.2 and 3.9 log10-transformed reductions of median peak sgRNA in BAL and nasal swabs, respectively, as compared with sham controls (P < 0.0001 and P < 0.0001, respectively, two-sided Mann–Whitney tests) (Fig. 5). Among the 32 vaccinated macaques, 17 were completely protected and had no detectable sgRNA in BAL or nasal swabs after challenge, and 5 additional macaques had no sgRNA in BAL but showed some virus in nasal swabs. (Mercado et al., 2020)