Therapeutic indications

Vaxzevria (Oxford-AstraZeneca vaccine) is indicated for active immunisation to prevent COVID-19 caused by SARS-CoV-2, in individuals ≥18 years old.

Active ingredient

Recombinant DNA encoding the SARS-CoV-2 viral spike (S) glycoprotein (ChAdOx1-S)

Dosage per shot

Adult: 0.5 mL

Method of administration

Intramuscular (IM) injection only, preferably in the deltoid muscle.

Recommended schedule

The Vaxzevria primary vaccination course consists of two separate doses of 0.5 ml each. The second dose should be administered between 4 and 12 weeks (28 to 84 days) after the first dose. Dosing intervals from 8-12 weeks have been associated with increased, longer- lasting efficacy. A booster dose (third dose) of 0.5 ml may be given to individuals who completed the primary vaccination course with Vaxzevria or an mRNA COVID-19 vaccine. The third dose should be administered at least 3 months after completing the primary vaccination course. Booster dose qualification and recommendation vary between countries and need to follow local guidelines.

Efficacy

Combined results from 4 clinical trials in the United Kingdom, Brazil and South Africa showed that Vaxzevria was safe and effective at preventing COVID-19 in people from 18 years of age.

The vaccine demonstrated around a 60% efficacy in these clinical trials. Another study conducted in the United States, Peru and Chile involved around 26,000 people, of whom 21% were above 65 years of age. The participants received the second dose 4 weeks after the first one. The study showed a 74% reduction in the number of symptomatic COVID-19 cases in people given the vaccine compared with people given control.

A recent study shows that Vaxzevria (ChAdOx1-S) was effective at preventing COVID-19 infections due to Omicron when used as a fourth dose booster. In the real-world evidence study, Vaxzevria showed vaccine effectiveness (VE) of 73% against the highly transmissible Omicron variant when a fourth dose was given on top of any previous primary or booster vaccine.

Special warning and precautions for use

Information is available in the summary of product characteristics, please see https://www.ema.europa.eu/en/documents/product-information/vaxzevria-previously-covid-19-vaccine-astrazeneca-epar-product-information_en.pdf .

For information on clinical trials that are testing the use of the AstraZeneca COVID-19 Vaccine for active immunization against COVID-19, please see www.clinicaltrials.gov.

For COVID-19 Vaccine policies for pregnant and lactating people worldwide, please see, Pregnancy and Lactation Positions by Country for the Vaxzevria vaccine (Oxford-AstraZeneca).

References

https://www.who.int/news-room/feature-stories/detail/the-oxford-astrazeneca-covid-19-vaccine-what-you-need-to-know

Chariyalertsak S, et al. Effectiveness of heterologous 3rd and 4th dose COVID-19 vaccine schedules for SARS-CoV-2 infection during delta and omicron predominance in Thailand. Available at: Effectiveness of heterologous 3rd and 4th dose COVID-19 vaccine schedules for SARS-CoV-2 infection during delta and omicron predominance in Thailand. | Research Square. Accessed June 2022