Janssen COVID-19 vaccine
The Janssen COVID19 vaccine, sold under the brand name Jcovden, is a COVID19 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 COVID19. 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 phaseIII 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 COVID19, with an 85% efficacy in preventing severe COVID19 and 100% efficacy in preventing hospitalization or death caused by the disease.
The vaccine has been granted an emergency use authorization by the US Food and Drug Administration and a conditional marketing authorization by the European Medicines Agency 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 COVID19 vaccine, the US Centers for Disease Control and Prevention recommends "preferential use of mRNA COVID19 vaccines over the Janssen COVID19 vaccine, including both primary and booster doses administered to prevent COVID19, for all persons aged 18 years of age and older. The Janssen COVID19 vaccine may be considered in some situations, including for persons with a contraindication to receipt of mRNA COVID19 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 COVID19 vaccine is used to provide protection against infection by the SARS-CoV-2 virus in order to prevent COVID19 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 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.| Severity of illness | Delta | Alpha | Beta | Lineage B.1 |
| Asymptomatic | ||||
| Moderate to severe | ||||
| Severe to critical |
In October 2021, Janssen reported at a meeting of the US Food and Drug Administration Vaccines and Related Biological Products Advisory Committee 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 globally and to in the US and that it also increased efficacy against severe disease to nearly globally.
Pharmacology
The vaccine consists of a replication-incompetent recombinant adenovirus type 26 viral vector expressing the severe acute respiratory syndrome coronavirus 2 spike protein in a stabilized conformation. The PER.C6 cell line derived from human embryonic retinal cells is used in the production 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 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, 2-hydroxypropyl-β-cyclodextrin , polysorbate 80, sodium chloride, sodium hydroxide, and hydrochloric acid.Manufacturing
Unpunctured vials may be stored between 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.
In December 2020, Johnson & Johnson and Reig Jofre, a Spanish pharmaceutical company, entered into an agreement to manufacture the vaccine at Reig Jofre's Barcelona facility.
In February 2021, Sanofi and Johnson & Johnson struck a deal for Sanofi to provide support and infrastructure at Sanofi's Marcy-l'Étoile, France facility to manufacture approximately twelve million doses of the Johnson & Johnson vaccine per month once authorized.
In March 2021, Johnson & Johnson and Aspen Pharmacare made a deal to manufacture 220 million vaccines at Aspen's Gqeberha facility in Eastern Cape, South Africa. They plan to distribute the vaccine to other countries, mainly in Africa, and also through the COVID-19 Vaccines Global Access program.
In March 2021, Merck & Co and Johnson & Johnson struck a deal for Merck to manufacture the Johnson & Johnson vaccine at two facilities in the United States to help expand the manufacturing capacity of the vaccine using provisions of the Defense Production Act. That same month, human error at a plant run by Emergent BioSolutions in Baltimore resulted in the spoilage of up to fifteen million doses of the Johnson & Johnson vaccine. The error, which was caught before the doses left the plant, delayed expected shipments of the Johnson & Johnson vaccine within the United States. As the error had involved combining ingredients of the Johnson & Johnson vaccine with the AstraZeneca vaccine, the Biden administration gave control of the plant to Johnson & Johnson and said the plant should produce only the Johnson & Johnson vaccine to avoid further mix-ups. In July 2021, the FDA authorized Emergent to resume production of the Janssen vaccine. 400million doses were destroyed.
Adverse effects
Review of Vaccine Adverse Events Reporting System safety monitoring data by the US Centers for Disease Control and Prevention through 21 April 2021,, showed that "97% of reported reactions after vaccine receipt were nonserious, consistent with preauthorization clinical trials data."The most common side effects of the vaccine in the trials were usually mild or moderate, occurred within two days after vaccination, and got better within 1 or 2 days.
The most common side effects are pain at the injection site, headache, tiredness, muscle pain, and nausea, affecting more than 1 in 10 people. Coughing, joint pain, fever, chills, redness, and swelling at the injection site occurred in less than 1 in 10 people. Sneezing, tremor, throat pain, rash, sweating, muscle weakness, pain in the arms and legs, backache, weakness, and feeling generally unwell occurred in less than 1 in 100 people. Rare side effects are hypersensitivity and itchy rash.
An increased risk of the rare and potentially fatal thrombosis with thrombocytopenia syndrome has been associated with mainly younger female recipients of the vaccine. This syndrome, marked by formation of blood clots in the blood vessels in combination with low levels of blood platelets 4–28 days after the vaccines administration, occurred at a rate of about 7 per 1 million vaccinated women aged 18–49 years old and it occurs more rarely in other populations.
Allergic reactions, including anaphylaxis, can occur in rare cases within a few minutes to one hour after receiving a dose.
In May 2021, with 7.98 million doses administered, the CDC reported four cases of anaphylaxis after vaccination and 28 cases of cerebral venous sinus thrombosis.
In July 2021, the US fact sheet for the vaccine was updated to indicate that there may be an increased risk of Guillain-Barré syndrome during the 42 days following vaccination. The European Medicines Agency listed Guillain-Barré syndrome as a very rare side effect of COVID19 Vaccine Janssen and added a warning in the product information.
In August 2021, the Pharmacovigilance Risk Assessment Committee recommended updating the product information to the European Medicines Agency that "cases of dizziness and tinnitus are linked to the administration of COVID19 vaccine Janssen." Tinnitus was later labeled as "very rare" in a final safety study by the manufacturer.
In December 2021, the CDC accepted the recommendation from a panel of experts for a preference of using the Pfizer-BioNech and Moderna vaccines over the Janssen vaccine due to rare but serious blood clotting events. In May 2022, the FDA limited the use of the Janssen vaccine to those over eighteen unable to access other vaccines or who are otherwise "medically ineligible" for other vaccine options.