- Johnson & Johnson announced the launch of its large-scale study (Phase 3 trial) to test a two-dose regimen of its experimental COVID-19 vaccine among thousands of volunteers.
- The U.S. drugmaker plans to enrol up to 30,000 participants globally for the study.
- The UK arm of the study is aiming to recruit 6,000 participants of the total 30,000 target.
- This study runs in parallel with Johnson & Johnson’s single-dose regimen trial launched in September, involving 60,000 participants.
WHAT’S THE DIFFERENCE BETWEEN ONE-DOSE & TWO-DOSE REGIMEN?
- When a COVID-19 vaccine comes to the market, people will likely need two doses. The second dose will allow the body better recognise proteins created by the COVID-19 virus.
- The second dose will increase immunity. However, how long that immunity lasts remains to be seen.
- It’s not uncommon to administer two-dose vaccines. Many other vaccines such as ones to protect against measles or rubella require back-to-back doses to be most effective.
- Last week, Pfizer and BioNTech said interim results from its COVID-19 vaccine trials showed 90 percent effectiveness. This vaccine requires a two-dose regimen to achieve that high effectiveness. The two shots are administered 21 days apart.
- In Johnson & Johnson’s two-dose regimen study, participants will be given a first dose of either a placebo or the experimental shot, currently called Ad26COV2, followed by a second dose or placebo 57 days later.
- The company said the two-dose trial follows positive interim results from the company's study that showed a single dose of its vaccine candidate induced a robust immune response.
HOW IS JOHNSON & JOHNSON’S VACCINE DIFFERENT FROM PFIZER’S?
- Pfizer-BioNtech vaccine uses a new form of biotechnology known as messenger RNA or mRNa.
- How does it work? mRNA vaccines train the body’s immune system to recognize a threat like a virus. The body then produces antibodies to protect itself against the virus.
- Meanwhile, Johnson & Johnson’s candidate vaccine uses a common cold virus known as adenovirus type 26, or Ad26, to deliver coronavirus proteins into cells in the body, prompting the body to mount an immune defense against the virus.
- The vaccine uses the same technology used for Johnson & Johnson's Ebola, Zika and HIV vaccines.
- Vaccine researcher at Beth Israel Deaconness Dr. Dan Barouch, who led the research in collaboration with Johnson & Johnson said this: “This study shows that even just a single immunization with the Ad26 vaccine leads to neutralizing antibody responses and robust protection of monkeys against COVID-19.”
THE POTENTIAL AND CHALLENGES
- Distributions of vaccines come with supply-chain challenges
- One potential advantage for Johnson & Johnson’s is that its vaccine candidate does not need to be kept as cold as some other vaccines, which is important for distribution to developing countries.
- Pzifer and BioNTech candidate vaccine needs to be kept at - 70 degrees Celsius or below.
- Johnson & Johnson said its vaccine is expected to be stable at refrigerated temperatures of -20 degrees Celsius and at least three months at 2-8 degrees Celsius.
- The flu vaccine must be kept at 2-8 degrees Celsius, either inside a refrigerator or inside a properly chilled insulated cooler.
