The Janssen COVID‑19 vaccine, (Ad26.COV2.S) sold under the brand name Jcovden, is a COVID‑19 vaccine that was developed by Janssen Vaccines in Leiden, Netherlands, and its Belgian parent company Janssen Pharmaceuticals, a subsidiary of American company Johnson & Johnson. It is a viral vector vaccine based on a human adenovirus that has been modified to contain the gene for making the spike protein of the SARS-CoV-2 virus that causes COVID‑19. The body's immune system responds to this spike protein to produce antibodies. The vaccine requires only one dose and does not need to be stored frozen. Clinical trials for the vaccine were started in June 2020, with phase III involving around 43,000 people. In January 2021, Janssen announced that 28 days after a completed vaccination, the vaccine was 66% effective in a one-dose regimen in preventing symptomatic COVID‑19, with an 85% efficacy in preventing severe COVID‑19 and 100% efficacy in preventing hospitalization or death caused by the disease. The vaccine has been granted an emergency use authorization (EUA) by the US Food and Drug Administration (FDA) and a conditional marketing authorization by the European Medicines Agency (EMA) and the UK Medicines and Healthcare products Regulatory Agency. In June 2023, the FDA revoked the emergency use authorization for the Janssen COVID-19 vaccine at the request of its manufacturer. Because cases of thrombosis with thrombocytopenia syndrome and Guillain-Barré syndrome have been reported after receipt of the Janssen COVID‑19 vaccine, the US Centers for Disease Control and Prevention (CDC) recommends "preferential use of mRNA COVID‑19 vaccines over the Janssen COVID‑19 vaccine, including both primary and booster doses administered to prevent COVID‑19, for all persons aged 18 years of age and older. The Janssen COVID‑19 vaccine may be considered in some situations, including for persons with a contraindication to receipt of mRNA COVID‑19 vaccines." In February 2022, Johnson & Johnson announced it has temporarily suspended production of the vaccine though they also noted that it will likely resume at some point in the future and that it will honor all pre-existing contracts that oblige Janssen to supply its vaccine by using the millions of already existing vaccine doses in its inventory where requested.
Medical uses The Janssen COVID‑19 vaccine is used to provide protection against infection by the SARS-CoV-2 virus in order to prevent COVID‑19 in people aged eighteen years and older. The vaccine is given by intramuscular injection into the deltoid muscle. The initial course consists of a single dose. There is no evidence that a second booster dose is needed to prevent severe disease in healthy adults. In October 2021, the US Centers for Disease Control and Prevention (CDC) began recommending a booster dose.
Efficacy A vaccine is generally considered effective if the estimate is ≥50% with a >30% lower limit of the 95% confidence interval. Efficacy is closely related to effectiveness, which is generally expected to slowly decrease over time.
In October 2021, Janssen reported at a meeting of the US Food and Drug Administration Vaccines and Related Biological Products Advisory Committee (VRBPAC) that a single dose produced durable protection against severe disease and hospitalization for at least 6 months in the United States, even when Delta emerged, but also a global decrease in protection against moderate disease attributed to emerging variants outside the US. Janssen also reported that a booster dose given 2 months after the primary dose increased efficacy against symptomatic disease to 75% (95% CI, 55–87%) globally and to 94% (59–100%) in the US and that it also increased efficacy against severe disease to nearly 100% (33–100%) globally.
Pharmacology The vaccine consists of a replication-incompetent recombinant adenovirus type 26 (Ad26) viral vector expressing the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein in a stabilized conformation. The PER.C6 cell line derived from human embryonic retinal cells is used in the production (replication) of the Ad26 adenovirus vector. It is similar to the approach used by the Oxford–AstraZeneca COVID-19 vaccine and the Russian Sputnik V COVID-19 vaccine which use human embryonic kidney (HEK) 293 cells for adenovirus vector replication. The Ad26 viral vector lacks the E1 gene required for replication. Therefore, it cannot replicate in the human organism.
Chemistry The vaccine contains the following excipients: citric acid monohydrate, trisodium citrate dihydrate, ethanol (alcohol), 2-hydroxypropyl-β-cyclodextrin (HBCD) (hydroxypropyl betadex), polysorbate 80, sodium chloride, sodium hydroxide, and hydrochloric acid.
Manufacturing Unpunctured vials may be stored between 9 and 25 °C (48 and 77 °F) for up to twelve hours, and the vaccine can remain viable for months in a standard refrigerator. It is not shipped or stored frozen. In April 2020, Johnson & Johnson entered a partnership with Catalent to provide large-scale manufacturing of the Johnson & Johnson vaccine at Catalent's Bloomington, Indiana facility. In July 2020, the partnership was expanded to include Catalent's facility in Anagni, Italy. In September 2020, Grand River Aseptic Manufacturing agreed with Johnson & Johnson to support the manufacture of the vaccine, including technology transfer and fill and finish manufacture, at its Grand Rapids, Michigan facility.
… excerpt ends here. Continue reading the full article.
