science

Oxford–AstraZeneca COVID-19 vaccine

Oxford–AstraZeneca COVID-19 vaccine is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Oxford–AstraZeneca COVID-19 vaccine rather than just read about it. In short: The Oxford–AstraZeneca COVID‑19 vaccine, sold under the brand names Covishield and Vaxzevria among others, is a viral vector vaccine for the prevention of COVID-19. It was developed in the United Kingdom by Oxford University and British-Swedish company AstraZeneca, using as a vector the modified chimpanzee adenovirus ChAdOx1.

Key takeaways

Oxford–AstraZeneca COVID-19 vaccine belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Oxford–AstraZeneca COVID-19 vaccine to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Oxford–AstraZeneca COVID-19 vaccine from memory before moving on to harder problems.

Reference excerpt

The Oxford–AstraZeneca COVID‑19 vaccine, sold under the brand names Covishield and Vaxzevria among others, is a viral vector vaccine for the prevention of COVID-19. It was developed in the United Kingdom by Oxford University and British-Swedish company AstraZeneca, using as a vector the modified chimpanzee adenovirus ChAdOx1. The vaccine is given by intramuscular injection. Studies carried out in 2020 showed that the efficacy of the vaccine is 76.0% at preventing symptomatic COVID-19 beginning at 22 days following the first dose and 81.3% after the second dose. A study in Scotland found that, for symptomatic COVID-19 infection after the second dose, the vaccine is 81% effective against the Alpha variant (lineage B.1.1.7) and 61% against the Delta variant (lineage B.1.617.2). The vaccine is stable at refrigerator temperatures and has a good safety profile, with side effects including injection-site pain, headache, and nausea, all generally resolving within a few days. More rarely, anaphylaxis may occur; the UK Medicines and Healthcare products Regulatory Agency (MHRA) has 268 reports out of some 21.2 million vaccinations as of 14 April 2021. In very rare cases (around 1 in 100,000 people), the vaccine has been associated with an increased risk of blood clots when in combination with low levels of blood platelets (embolic and thrombotic events after COVID-19 vaccination). According to the European Medicines Agency, as of 4 April 2021, a total of 222 cases of blood clots had been recorded among 34 million people who had been vaccinated in the European Economic Area (a percentage of 0.0007%). On 30 December 2020, the vaccine was first approved for use in the UK vaccination programme, and the first vaccination outside of a trial was administered on 4 January 2021. The vaccine has since been approved by several medicine agencies worldwide, such as the European Medicines Agency (EMA), and the Australian Therapeutic Goods Administration (provisional approval in February 2021), and was approved for an Emergency Use Listing by the World Health Organization (WHO). More than 3 billion doses of the vaccine were supplied to countries worldwide. Some countries have limited its use to elderly people at higher risk for severe COVID-19 illness due to concerns over the very rare side effects of the vaccine in younger individuals. The vaccine is no longer in production. AstraZeneca withdrew its marketing authorisations for the vaccine from the European market in March 2024, and worldwide by May 2024.

Medical uses The Oxford–AstraZeneca COVID‑19 vaccine is used to provide protection against infection by the SARS-CoV-2 virus in order to prevent COVID-19 in adults aged 18 years and older. The medicine is administered by two 0.5 ml (0.017 US fl oz) doses given by intramuscular injection into the deltoid muscle (upper arm). The initial course consists of two doses with an interval of 4 to 12 weeks between doses. The World Health Organization (WHO) recommends an interval of 8 to 12 weeks between doses for optimal efficacy. As of August 2021, there is no evidence that a third booster dose is needed to prevent severe disease in healthy adults.

Effectiveness Preliminary data from a study in Brazil with 61 million individuals from January to June 2021, indicate that the effectiveness against infection, hospitalisation and death is similar between most age groups, but protection against all these outcomes is significantly reduced in those aged 90 year of age or older, attributable to immunosenescence. A vaccine is generally considered effective if the estimate is ≥50% with a >30% lower limit of the 95% confidence interval. Effectiveness is generally expected to slowly decrease over time.

Preliminary data suggest that the initial two-dose regimen is not effective against symptomatic disease caused by the Omicron variant from the 15th week onwards. A regimen of two doses of the Oxford–AstraZeneca vaccine followed by a booster dose of the Pfizer–BioNTech or the Moderna vaccine is initially about 60% effective against symptomatic disease caused by Omicron, then after 10 weeks the effectiveness drops to about 35% with the Pfizer–BioNTech and to about 45% with the Moderna vaccine. The vaccine remains effective against severe disease, hospitalisation and death.

Contraindications The Oxford–AstraZeneca COVID-19 vaccine should not be administered to people who have had capillary leak syndrome.

Adverse effects The most common side effects in the clinical trials were usually mild or moderate and got better within a few days after vaccination. Vomiting, diarrhoea, fever, swelling, redness at the injection site and low levels of blood platelets occurred in less than 1 in 10 people. Enlarged lymph nodes, decreased appetite, dizziness, sleepiness, sweating, abdominal pain, itching and rash occurred in less than 1 in 100 people. An increased risk of the rare and potentially fatal thrombosis with thrombocytopenia syndrome (TTS) has been associated with mainly younger female recipients of the vaccine. Analysis of VigiBase reported embolic and thrombotic events after vaccination with Oxford–AstraZeneca, Moderna and Pfizer vaccines, found a temporally related incidence of 0.21 cases per 1 million vaccinated-days. Anaphylaxis and other allergic reactions are known side effects of the Oxford–AstraZeneca COVID-19 vaccine. The European Medicines Agency (EMA) has assessed 41 cases of anaphylaxis from around 5 million vaccinations in the United Kingdom. Capillary leak syndrome is a possible side effect of the vaccine. The European Medicines Agency (EMA) listed Guillain-Barré syndrome as a very rare side effect of the Oxford–AstraZeneca COVID-19 vaccine and added a warning in the product information. Additional side effects include tinnitus (persistent ringing in the ears), paraesthesia (unusual feeling in the skin, such as tingling or a crawling sensation), and hypoaesthesia (decreased feeling or sensitivity, especially in the skin).

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Oxford–AstraZeneca COVID-19 vaccine

Start with the simplest possible case. Write down what Oxford–AstraZeneca COVID-19 vaccine claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Oxford–AstraZeneca COVID-19 vaccine before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Oxford–AstraZeneca COVID-19 vaccine ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Oxford–AstraZeneca COVID-19 vaccine

In research: Oxford–AstraZeneca COVID-19 vaccine appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Oxford–AstraZeneca COVID-19 vaccine in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Oxford–AstraZeneca COVID-19 vaccine is common in secondary-school and first-year university syllabi. It links to neighbouring topics Adenoviridae, British COVID-19 vaccines, Drugs developed by AstraZeneca, so understanding it makes those chapters shorter.
In everyday life: Look for Oxford–AstraZeneca COVID-19 vaccine outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Oxford–AstraZeneca COVID-19 vaccine” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Oxford–AstraZeneca COVID-19 vaccine in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Oxford–AstraZeneca COVID-19 vaccine means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Oxford–AstraZeneca COVID-19 vaccine out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Oxford–AstraZeneca COVID-19 vaccine in simple terms?

Why does Oxford–AstraZeneca COVID-19 vaccine matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Oxford–AstraZeneca COVID-19 vaccine?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Oxford–AstraZeneca COVID-19 vaccine.