COVID-19 Frequently asked questions

Last updated August 2021


How is AstraZeneca responding to the COVID-19 global pandemic?

AstraZeneca is responding to the COVID-19 global pandemic in a manner consistent with our values: to follow the science, put patients first and do the right thing.

We continue to support the global effort to fight the pandemic, collaborating with scientists, governments and multilateral organisations, to accelerate efforts to advance the development of potential medicines to prevent or treat the infection, to boost diagnostic testing and to help protect healthcare workers on the frontline.

We joined forces with the University of Oxford1 to bring together its world-class expertise in vaccinology with our global development and manufacturing capabilities. We have accelerated development and rapidly mobilised a global supply chain to supply the potential vaccine broadly and equitably across the globe, when approvals are granted, and at no profit during the pandemic2.

Complementing our vaccines approach, we also quickly mobilised research efforts to advance the development of a coronavirus-neutralising long-acting antibody combination (LAAB) for the potential prevention and treatment of COVID-19. 

We continue to ensure the supply and quality of our medicines to patients and to safeguard the health and wellbeing of all our employees. We have also provided our expertise in science and technology to international health authorities, such as the World Health Organization (WHO) and the European Federation of Pharmaceutical Industries and Associations (EFPIA).

What is the status of vaccine development?

Clinical development of the vaccine is ongoing, assessing efficacy, safety and immune responses in up to 60,000 participants globally across a broad age range and diverse racial, ethnic and geographic groups.

Looking at all the data from clinical trials and real world evidence, our vaccine is well tolerated3 and highly effective4 against COVID-19 across all disease severities with similar efficacy across all demographics and in particular all adult age groups, including in individuals aged 65 years and over.

The vaccine has been shown to:

  • ...reduce severe disease and hospitalisation from COVID-19 infection with 100% efficacy in clinical trials5 in up to 60,000 participants, and by more than 80% from real world evidence in tens of millions of people
  • effective against all severities of symptomatic COVID-19 across ethnicities and age, with ~80% efficacy in clinical trials and a trend of increased efficacy with a longer than 4 week dosing interval.

Pre-clinical and clinical studies have been conducted to evaluate the effectiveness of Covid-19 Vaccine AstraZeneca against three global variants of concern.

  • Clinical studies 6 confirmed the vaccine is effective against the B.1.1.7 variant, with comparable efficacy to the predominant global strain
  • Pre-clinical studies 7 showed antibodies from vaccinated individuals were able to neutralise the P.1. variant to a similar extent as the Victoria strain and B.1.1.7 variant, indicating similar levels of protection could be achieved against this variant in the real world setting.
  • Analysis from the small Phase I/II COV005 trial in South Africa 8was unable to conclude that the vaccine protects against severe disease from the B.1.351variant due to the young average age of the trial participants. Pre-clinical studies have demonstrated the vaccine’s effectiveness against the B.1.351 variant, showing lower respiratory tract protection and viral clearance in animal models9. Further clinical analysis is planned to confirm the effectiveness against severe disease from this variant.

The World Health Organisation’s Strategic Advisory Group of Experts on Immunization (SAGE) has recommendedCOVID-19 Vaccine AstraZeneca in countries where new variants, including B.1.351 are prevalent.

The vaccine has been granted a conditional marketing authorisation or emergency use in more than 70 countries across six continents, and with the recent Emergency Use Listing granted by the World Health Organization this accelerates the pathway to access in up to 142 countries through the COVAX Facility.

AstraZeneca are committed to broad and equitable supply of the vaccine at no profit during the period of the pandemic. We continue to identify and forge partnerships to develop a number of supply chains around the world.

Clinical trials are being initiated to study vaccine effectiveness across different populations, for example paediatrics and pregnant women and investigating interchangeability across different vaccine platforms, known as heterologous boosting.

We are deeply committed to the safety of our participants and to maintaining the highest standards of conduct across all our clinical trials.

What is the status of the long-acting antibody (LAAB) development?

Clinical development of the long-acting antibody (LAAB) combination is ongoing, assessing efficacy and safety as a potential prevention and treatment in up to 9,000 participants globally across a range of ages and diverse racial, ethnic and geographic groups.10-15 Discovered by Vanderbilt University and licensed to AstraZeneca in June 2020,16 the antibodies were optimised by AstraZeneca with half-life extension and Fc Receptor binding reduction.17-21

In clinical trials, the LAAB has been shown to:

  • Significantly reduce the risk of developing symptomatic COVID-19 compared to placebo
  • Be generally well-tolerated

Preliminary ‘in vitro’ findings from investigators at Oxford University and Columbia University have demonstrated that the two-LAAB combination neutralises recent emergent SARS-CoV-2 viral variants, including the Delta variant. 22-27

AstraZeneca will continue to work with international and government agencies around the world to make the LAAB accessible to high-risk populations as another valuable option in the fight against COVID-19, should it prove to be effective and well-tolerated. We are deeply committed to the safety of our participants and to maintaining the highest standards of conduct across all our clinical trials.

How is AstraZeneca ensuring the continuity of its supply of medicines?

Our medicines supply chain is robust and we have business continuity plans in place to ensure that patients continue to receive their medicines. We have not had, and do not anticipate, any disruption to supply.

Have ongoing or new clinical trials been stopped or put on hold?

As a science-led biopharmaceutical company, our ongoing clinical research is crucial to the development of innovative new medicines and we have taken appropriate measures to ensure continuity and mitigate any impact to our research and development programmes. We have focused on ensuring the continued safety of patients in all our ongoing clinical trials, while activating continuity plans in order to minimise trial disruption from the pandemic.

Our mitigation strategies include home-based treatment and monitoring options, moving patient recruitment to less-affected regions, and planning for accelerated recruitment once the pandemic has receded. As always, our highest priority is to protect the safety and wellbeing of employees and the patients involved in our clinical trials.

Is AstraZeneca developing diagnostic tests for COVID-19?

We are providing our world class scientific and technical expertise to help boost COVID-19 testing. We are accelerating the development of our diagnostic testing capabilities to scale-up screening, and we are collaborating with governments on existing screening programmes to supplement testing.

In the UK, we formed a collaboration with the University of Cambridge and GSK to support the government’s national effort to boost COVID-19 testing. The new testing facility was operational in just five weeks – a task which would usually take six months and is testament to the strength of both the UK’s life sciences sector and the life sciences cluster in Cambridge.

What philanthropic initiatives has AstraZeneca supported for the pandemic?

We donated nine million face masks to support healthcare workers around the world as they respond to the COVID-19 global pandemic. We partnered with the World Economic Forum’s COVID-19 Action Platform, created with the support of the World Health Organisation (WHO), to identify countries in greatest need and inform the direction of our donation. The nine million masks included a mixture of both surgical and N95 masks, depending on country requirements.

In direct response to the COVID-19 global pandemic, we have also donated US$1 million to our Young Health Programme and emergency response partners for the work they are doing to support the needs of children, youth and vulnerable populations in low- and middle-income countries around the world. This is aligned to our global philanthropic focus on young people and the prevention of non-communicable diseases.

Is the AstraZeneca vaccine available for private purchase?

Our current focus is delivering on our substantial global commitments to governments and international health organizations, as quickly as possible to help end the pandemic; as such there is currently no private sector supply, sale or distribution of the vaccine.

If someone offers private vaccines, it is likely counterfeit, so should be refused and reported to local health authorities.


1. AstraZeneca PLC. AstraZeneca and Oxford University announce landmark agreement for COVID-19 vaccine. Available at:  [Last Accessed: Jan 2021]

2. AstraZeneca PLC. AstraZeneca to supply Europe with up to 400 million doses of Oxford University’s vaccine at no profit. Available at: [Last accessed: Sept 2020]

3. Voysey M, Clemens SAC, Madhi SA, et al. Single-dose administration and the influence of the timing of the booster dose on immunogenicity and efficacy of ChAdOx1 nCoV-19 (AZD1222) vaccine: a pooled analysis of four randomised trials. [Online]. Available at: [Last accessed: 21 Mar 2021]

4. AstraZeneca PLC. COVID-19 Vaccine AstraZeneca confirms 100% protection against severe disease, hospitalisation and death in the primary analysis of Phase III trials. [Online]. Available at: [Last accessed: 21 Mar 2021]

5. Voysey M, Clemens SAC, Madhi SA, et al; Oxford COVID Vaccine Trial Group. Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK. Lancet. 2021; 397 (10269): 99-111. 

6. Emary KRW, Golubchik T, Aley PK, et al; Consortium, COVID-19 Genomics UK (COG-UK) Group; Oxford COVID Vaccine Trial. Efficacy of ChAdOx1 nCoV-19 (AZD1222) Vaccine Against SARS-CoV-2 VOC 202012/01 (B.1.1.7). [Online] Available at SSRN: or [Last accessed: 21 Mar 2021]

7. Dejnirattisai, W., Zhou, D., Supasa, P., et al. Antibody evasion by the Brazilian P.1. strain of SARS-CoV-2. bioRxiv [Online as pre-print]. Available at: [Last accessed: 21 March 2021]

8. Madhi, S., Baillie, V., Cutland, C. et al. Efficacy of the ChAdOx1 nCoV-19 Covid-19 Vaccine against the B.1.351 Variant. [Online] Available at [Last accessed: 21 March 2021]

9. Fischer, R.J., van Doremalen, N., Adney, D.R. et al.; ChAdOx1 nCoV-19 (AZD1222) protects hamsters against SARS-CoV-2 B.1.351 and B.1.1.7 disease. bioRxiV [Online as pre-print]. Available at: [Last accessed: 17 March 2021]

10. Phase III Double-blind, Placebo-controlled Study of AZD7442 for Pre-exposure Prophylaxis of COVID-19 in Adult. (PROVENT). [Online]. Available at: [Last accessed: 5 May 2021].

11. Phase III Double-blind, Placebo-controlled Study of AZD7442 for Post- Exposure Prophylaxis of COVID-19 in Adults (STORM CHASER). [Online]. Available at: [Last accessed: 5 May 2021].

12. Phase III Study of AZD7442 for Treatment of COVID-19 in Outpatient Adults (TACKLE). [Online]. Available at: [Last accessed: 5 May 2021].

13. ACTIV-2: A Study for Outpatients With COVID-19. [Online]. Available at: [Last accessed: 5 May 2021].

14. ACTIV-3: Therapeutics for Inpatients With COVID-19 (TICO). [Online]. Available at: [Last accessed: 5 May 2021].

15. Trial of Treatments for COVID-19 in Hospitalized Adults (DisCoVeRy). [Online]. Available at: [Last accessed: 5 May 2021]

16. AstraZeneca news release. Advancing our discovery of novel coronavirus-neutralising antibodies against COVID-19. [Online]. Available at: [Last accessed: 5 May 2021].

17. Robbie GJ, et al. A novel investigational Fc-modified humanized monoclonal antibody, motavizumab-YTE, has an extended half-life in healthy adults. Antimicrob Agents Chemother. 2013; 57 (12): 6147-53.

18. Griffin MP, et al. Safety, tolerability, and pharmacokinetics of MEDI8897, the respiratory syncytial virus prefusion F-targeting monoclonal antibody with an extended half-life, in healthy adults. Antimicrob Agents Chemother. 2017;61(3): e01714-16.

19. Yu XQ, et al. Safety, tolerability, and pharmacokinetics of MEDI4893, an investigational, extended-half-life, anti-staphylococcus aureus alpha-toxin human monoclonal antibody, in healthy adults. Antimicrob Agents Chemother. 2016; 61 (1): e01020-16.

20. Domachowske JB, et al. Safety, tolerability and pharmacokinetics of MEDI8897, an extended half-life single-dose respiratory syncytial virus prefusion F-targeting monoclonal antibody administered as a single dose to healthy preterm infants. Pediatr Infect Dis J. 2018;37(9): 886-892.

21. van Erp EA, et al. Fc-mediated antibody effector functions during respiratory syncytial virus infection and disease. Front Immunol. 2019; 10: 548

22. Liu C, et al. Reduced neutralization of SARS-CoV-2 B.1.617 by vaccine and convalescent serum. Cell. 2021

23. Zhou D, et al. Evidence of escape of SARS-CoV-2 variant B.1.351 from natural and vaccine induced sera [published online ahead of print, 2021 Feb 23]. Cell. 2021; doi:10.1016/j.cell.2021.02.037.

24. Dejnirattisai W, et al. Antibody evasion by the Brazilian P.1 strain of SARS-CoV-2. 2021 bioRxiv [preprint available];

25. Wang P, et al. Antibody resistance of SARS-CoV-2 variants B.1.351 and B.1.1.7. Nature 2021 Mar 8. doi: 10.1038/s41586-021-03398-2. Epub ahead of print. PMID: 33684923.

26. Chen RE, et al. Resistance of SARS-CoV-2 variants to neutralization by monoclonal and serum-derived polyclonal antibodies. Nat Med 2021; 27, 717–726.

27. Wang P, et al. Increased resistance of SARS-CoV-2 variant P.1 to antibody neutralization. Cell Host Microbe. 2021; 29 (5): 747–751.e4.

Veeva ID: Z4-36650 
Date of Preparation: August 2021