The HTAC recommends the emergency use of the AstraZeneca COVID-19 Vaccine to prevent COVID-19 for persons aged 18 and older within identified priority groups. 

COVID-19 Vaccine (ChAdOx1-S [recombinant]) (COVID-19 Vaccine AstraZeneca) under emergency use

The Food and Drug Administration (FDA) issues emergency use authorization (EUA) for unregistered vaccines and drugs during public health emergencies. This authorization expedites the availability of interventions for affected populations. Before issuing EUA, regulatory agencies consider quality, safety, and efficacy criteria. All vaccines must first receive EUA before use for immunization. 

The Health Technology Assessment Council (HTAC) recommends the emergency use of the COVID-19 Vaccine (ChAdOx1-S [recombinant]) (COVID-19 Vaccine AstraZeneca) to reduce the burden of COVID-19 among individuals 18 years and older, prioritizing the most at-risk and vulnerable populations. The Council in its interim analysis and recommendation considers best available scientific evidence, which has since revealed the vaccine’s capacity to prevent symptomatic COVID-19 infection in the short-term, with benefits outweighing risks. Researchers worldwide continue to collect and monitor data to establish its long-term efficacy and safety and its potential to reduce COVID-19 transmission. 

Who should receive the vaccine?

Persons belonging to identified priority groups aged 18 or older may receive COVID-19 Vaccine (ChAdOx1-S [recombinant]) (COVID-19 Vaccine AstraZeneca).

Who should NOT receive the vaccine?

  • Persons with history of anaphylaxis, allergic reactions of any severity, or hypersensitivity to active ingredients (or other related molecules) that occur within 4 hours from vaccination
  • Persons below 18 years of age

What are the contraindications associated with the vaccine?

The COVID-19 Vaccine (ChAdOx1-S [recombinant]) (COVID-19 Vaccine AstraZeneca) uses a single recombinant, replication-deficient chimpanzee viral vector (ChAdOx1) based on a weakened adenovirus strain. The vaccine does not contain inactivated SARS-CoV-2 pathogen particles, and hence is non-infectious.

  Reported adverse events

  • Anaphylaxis, allergic reactions of any severity, or hypersensitivity to the following excipients:
    • L-Histidine
    • L-Histidine hydrochloride monohydrate
    • Magnesium chloride hexahydrate
    • Polysorbate 80
    • Ethanol
    • Sucrose
    • Sodium chloride
    • Disodium edetate dihydrate
    • Water for injections
  • Tenderness and/or pain in injection site
  • Headache
  • Malaise or myalgia
  • Chills or pyrexia
  • Nausea or arthralgia 

What precautions should be considered before administering the vaccine?

  • For those with history of immediate allergic reaction or hypersensitivity to any other injectable therapy, such as intramuscular, intravenous, or subcutaneous vaccines unrelated to a component of mRNA COVID-19 vaccines, treatment for severe allergic reactions must be available
  • For persons with coagulation disorder (such as thrombocytopenia) or persons receiving anticoagulation therapy, vaccine must be administered strictly under physician supervision
  • For those with concurrent moderate to severe acute illness, for immunocompromised persons or those receiving immunosuppressive therapy, vaccination may be subject to physician advice
  • For persons 56 years old and older, vaccination may be subject to physician supervision and advice
  • For pregnant and breastfeeding women excluded from other priority groups, vaccination may be subject to physician supervision and advice

How should the vaccine be stored?

Our national COVID-19 vaccination program follows the World Health Organization (WHO)-prescribed cold chain storage protocol for mRNA vaccines.

  • Stored properly in a refrigerated container between 2° and 8°C, unopened multidose vials can last up to 6 months. Do not freeze. Keep the vaccines in their external cartons to protect against direct light.
  • While in use, keep the vaccines in temperatures between 2°C and 25°C.

How should the vaccine be prepared before administration?

   General Information and Preparation for COVID-19 Vaccine (ChAdOx1-S [recombinant]) (COVID-19 Vaccine AstraZeneca)

    • 10-dose, clear type I glass vial (Pack of 10)
      • 5mL solution
      • Halobutyl rubber stopper
      • Aluminum overseal, plastic flip-off cap
    • 8-dose, clear type I glass vial (Pack of 10)
      • 4mL solution 
      • Halobutyl rubber stopper
      • Aluminum overseal, plastic flip-off cap

   Preparing the vaccine

    1. Assess recipient status. Screen for potential contraindications and precautions, and review their vaccination history.
    2. Observe aseptic techniques. Perform hand hygiene before preparing the vaccine, between recipients, when replacing gloves*, and at any other time hands become soiled.
    3. NEVER use expired vaccines. Check expiration dates before use.
    4. Inspect vials for particulate matter or discoloration. The solution appears colorless to slightly brown, with clear to slightly opaque consistency. NEVER use vials with discolored liquid. Do NOT shake the vial.
    5. Keep the vaccines between 2°C and 25°C and administer them within 6 hours; otherwise, discard unused vaccines. 

*Gloves are not recommended unless the vaccinator will likely come in contact with potentially infectious bodily fluids or open wounds. Where worn, follow aseptic technique. Perform hand hygiene and switch gloves between recipients.

How should the vaccine be administered?

Make sure to wear complete and correct personal protective equipment (PPE) before administering the vaccines.

  1. Choose the correct equipment and needle size. Make sure to use a new, sterile needle and syringe for every injection.
  2. Use a new, sterile needle and syringe kit for every recipient. Follow aseptic technique when extracting the dose for administration. 
  3. Withdraw 0.5mL vaccine into a prepared syringe. Make sure to extract the required full dose; otherwise, discard the remaining volume.
  4. Bring the dose of vaccine from the preparation area to the administration area immediately following preparation. 
  5. Immediately administer the vaccine by intramuscular (IM) injection into the deltoid muscle. 

How should adverse events be managed?

In case of immediate adverse events or reactions following vaccination, observe within:

30 minutes 

  • Persons with history of immediate allergic reactions (of any severity) to vaccines or other injectable therapy, and
  • Persons with history of immediate allergic reactions due to any other cause

15 minutes

  • All other persons

Persons administering the vaccines should closely monitor, record, and report adverse reactions through the Adverse Events following Immunization (AEFI) Committee, national pharmacovigilance and surveillance systems.

How many days apart and what restrictions should be considered in administering doses?

  • Persons aged 18 and older should receive 2 separate 0.5mL vaccine doses between 4 and 12 weeks apart.
  • Persons receiving a first dose of COVID-19 Vaccine (ChAdOx1-S [recombinant]) (COVID-19 Vaccine AstraZeneca) should complete the vaccination series with the same product. 
    • Regulatory bodies have yet to assess the safety and efficacy of mixed-product dosage series. Both doses in the series must be completed using the same product. In case doses from different mRNA vaccines are inadvertently administered, the HTAC recommends no dosage adjustments for either product at this time.
  • Do not use the vaccine at the same time as other injectable therapies, remedies, or medicines. 


Read our guidance for the general public:

Read the Evidence Summary:


Information for Healthcare Professionals on COVID-19 Vaccine Astrazeneca. Government of the United Kingdom. Retrieved from