biology

SCB-2019

SCB-2019 is a biology 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 SCB-2019 rather than just read about it. In short: SCB-2019 is a protein subunit COVID-19 vaccine developed by Clover Biopharmaceuticals using an adjuvant from Dynavax technologies. Positive results of Phase I trials for the vaccine were published in The Lancet and the vaccine completed enrollment of 29,000 participants in Phase II/III trials in July 2021.

Key takeaways

SCB-2019 belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect SCB-2019 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of SCB-2019 from memory before moving on to harder problems.

Reference excerpt

SCB-2019 is a protein subunit COVID-19 vaccine developed by Clover Biopharmaceuticals using an adjuvant from Dynavax technologies. Positive results of Phase I trials for the vaccine were published in The Lancet and the vaccine completed enrollment of 29,000 participants in Phase II/III trials in July 2021. In September 2021, SCB-2019 announced Phase III results showing 67% efficacy against all cases of COVID-19 and 79% efficacy against all cases of the Delta variant. Additionally, the vaccine was 84% effective against moderate cases and 100% effective against hospitalization. SCB-2019 is being funded by CEPI as part of COVAX and has received advanced purchase orders from GAVI for 400 million doses, with production to begin in 2021.

Medical uses The vaccine was administered in 2 doses in 4 weeks.

Efficacy In September 2021, SCB-2019 announced Phase III results showing 67.2% efficacy against all cases of COVID-19 of any degree of severity, 83.7% efficacy against moderate-to-severe disease, and 100% against hospitalisation and severe cases. Additionally, the vaccine was 79% effective against all cases of Delta. Of the 207 cases found during the trials, 52 were from the vaccinated group and 155 from the placebo group. These Phase II/III results have been published in the Lancet. Clover expects to submit its Phase III results for approval by the World Health Organization, European Medicines Agency, and China's NMPA in the fourth quarter of 2021.

Efficacy against variants In Phase III trials, SCB-2019 showed efficacy of 81.7% for moderate-to-severe cases of COVID-19 caused by Delta, 91.8% for Gamma, and 58.6% for Mu. 56 Delta cases, 37 Mu cases, and 13 Gamma cases were recorded during the trials.

Pharmacology Subunit vaccines contain parts of the virus selected to stimulate an immune response, without including the entire virus. Because the fragments are incapable of causing disease, subunit vaccines are considered very safe. Subunit vaccines in widespread use include the Hepatitis B vaccine and Pertussis vaccine. SCB-2019 has a trimeric form of the SARS-CoV-2 spike protein (S-Trimer) combined with one of two different adjuvants AS03 (GlaxoSmithKline) or CpG/Alum (Dynavax). The vaccine displays the spike protein in its natural three-part form, leading to a potentially better immune response. The vaccine is similar to other subunit COVID-19 vaccines including Novavax, Abdala, and ZF2001. The vaccine is stable for at least six months under normal refrigeration conditions and at least one month at 40 degrees Celsius.

Manufacturing

CEPI and COVAX investment SCB-2019 is funded by CEPI as part of the COVAX. By November 2020, CEPI had invested $328 million to develop the vaccine. If the vaccine was successful, CEPI's investment would help scale-up production to over 1 billion doses a year. Previously, CEPI provided $3.5 million to support Phase I trials and later an additional $66 million in July 2020 to expand clinical testing and prepare sites for Phase II/III trials. In February 2021, Clover decided to proceed with the adjuvant from Dynavax for its Phase II/III trials over GlaxoSmithKline after evaluating manufacturing considerations. Separately, CEPI provided $99 million funding to Dynavax to produce its adjuvant for various COVID-19 vaccines. Vaccine production is expected to begin in 2021.

Orders In June 2020, GAVI announced an agreement with Clover for the purchase of 64 million doses in 2021 and an additional 350 million doses in 2022.

Clinical trials

Phase I & II trials In June 2020, Phase I trial were launched to assess safety, reactogenicity, and immunogenicity at multiple dose levels with 151 participants in Perth, Australia using 2 separate adjuvants, AS03 and CpG/Alum. In results published in The Lancet, SCB-2019 resulted in a strong immune responses against COVID-19, with high viral neutralizing activity (antibody geometric mean titres were 1567–4452 with AS03 and 174–2440 with CpG/Alum). Both adjuvanted vaccines were well tolerated and determined to be suitable for further clinical development. In August 2021, a Phase II trial will launch to assess immunogenicity and safety with 800 participants in China.

Phase II/III trials In March 2021, a larger combined-Phase II/III trial was launched to evaluate efficacy, immunogenicity, reactogenicity, and safety of the CpG/Alum adjuvated SCB-2019 vaccine. In July 2021, enrollment in the Phase II/III trials was completed with 45% of the 29,000 participants in Asia, 45% in Latin America and the rest in Europe and Africa.

Efficacy against variants In September 2021, results published in The Journal of Infectious Diseases showed SCB-2019 induced antibodies responses up to 184 days in the Phase I trial. Additionally, the vaccine produced neutralizing antibodies against three of the most common variants of concern; Alpha, Beta, and Gamma. In September 2021, the COVID-19 vaccine candidate showed 79% efficacy against the delta variant in its Phase II/III trials.

References

External links

Illustrations

Worked examples

Example 1 — a first encounter with SCB-2019

Start with the simplest possible case. Write down what SCB-2019 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, 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 SCB-2019 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 SCB-2019 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 SCB-2019

In research: SCB-2019 appears in biology 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 SCB-2019 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: SCB-2019 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Chinese COVID-19 vaccines, Clinical trials related to COVID-19, Protein subunit vaccines, so understanding it makes those chapters shorter.
In everyday life: Look for SCB-2019 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.

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How to study SCB-2019 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what SCB-2019 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 SCB-2019 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is SCB-2019 in simple terms?

Why does SCB-2019 matter?

Because it connects several biology 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 SCB-2019?

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 SCB-2019.