Covid-19 Vaccine (1) (Adenovirus Viral Vector)

What it is and how it works

A replication-deficient adenovirus (human or chimpanzee, depending on the product) carrying the gene for the SARS-CoV-2 spike protein. After administration, host cells express the spike antigen, stimulating neutralising antibody and cellular immune responses that protect against COVID-19.

Indications

Active immunisation to prevent COVID-19 caused by SARS-CoV-2 in individuals of the age groups specified for each product.

Dosage and administration (summary)

Given according to the national immunisation protocol and the product’s schedule (typically intramuscular injection of 0.5 mL as one or two doses, with boosters as recommended); some products are formulated for inhalation.

Contraindications

Severe allergic reaction to a previous dose or to any excipient; for some products, a history of thrombosis with thrombocytopenia syndrome after a previous dose or a history of capillary leak syndrome.

Warnings and precautions

Very rare thrombosis with thrombocytopenia syndrome (including cerebral venous sinus thrombosis), Guillain–Barré syndrome and capillary leak syndrome have been reported with adenovirus vector vaccines. Appropriate treatment for anaphylaxis must be available and recipients observed after vaccination. Use with caution in thrombocytopenia or coagulation disorders when given intramuscularly.

Pregnancy

Use in pregnancy follows national guidance and a benefit–risk assessment; data for viral vector vaccines are more limited than for other COVID-19 vaccines.

Storage and supply

Store refrigerated at 2–8 °C, do not freeze, protect from light; observe the manufacturer’s in-use time limits after opening multi-dose vials.

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.