So what makes these vaccines different from the rest. Yes, Johnson & Johnson’s single jab is a telling difference, but reports say that the company is working on a double-dose vaccine to improve its efficacy.
A one-dose coronavirus vaccine? That could be a gamechanger because more people could be vaccinated. Which means vaccination programmes can be speeded up if the production can keep up. “If it’s a single-dose vaccine, then a billion vaccine doses would translate into a billion people vaccinated,” Dr Dan Barouch of Harvard Medical School in the US told CNN.
The two new vaccines have done what the approved vaccines haven’t. They have proven to work (in trials) against most of the variants in circulation. Johnson & Johnson and Novavax have conducted Phase 3 trials in regions where the newer strains have been found. But significantly, both recorded lower efficacy in South Africa, where the most virulent variant has been found.
What are the vaccines?
Novavax vaccine: This is developed by Novavax, a company based in Maryland, US, and the Coalition for Epidemic Preparedness Innovations (CEPI). The protein-based coronavirus vaccine is called NVX-CoV2373.
How do Janssen and Novavax vaccines work?
Novavax: The Novavax vaccine uses a lab-made version of the SARS-CoV-2 spike protein, which is inserted into a virus and allowed to infect moth cells to produce spike proteins. These are harvested and assembled into nanoparticles to make the vaccine formulation. A chemical, called an adjuvant, is added to the mix to stimulate the immune system to respond more strongly to the nanoparticles.
How different are these vaccines from others?
Novavax: It works differently from the other vaccines, employing a recombinant nanoparticle technology. It uses protein to provoke an antibody response, and Matrix-M adjuvant enhances the immune response to the protein antigen. The Novavax vaccine can also destroy infected cells, according to a report in the New York Times.
How effective is the vaccine?
Novavax: The United Kingdom trials reported an efficacy rate of 89.3 per cent, according to results announced on January 28. The efficacy against the original COVID-19 strain was calculated to be 95.6 per cent, and it was around 86 per cent effective at protecting against the new UK variant.
Will it work against the South African variant?
Novavax: In South Africa trials, the efficacy rate was under 50 per cent. This could potentially be the result of B. 1.351 variant that can evade antibodies produced by the body. The company is working on a vaccine that is tailored to the variant.
What’s the dosage?
What are the potential side effects?
Novavax: No serious adverse events were reported in the trials. Other side effects were mild or absent, according to Novavax.
Who can take these vaccines?
Do they have to be stored at a freezing temperature?
Janssen: The vaccine can be stored at normal refrigerator temperatures. It is stable for up to three months at 2 degrees centigrade to 46 degrees centigrade, the company said. So health care facilities would not have to buy extra equipment to transport and store the vaccine safely. It will last for two years if kept at minus 20C.
Novavax: The vaccine would be easier to store and distribute as it can stay stable for up to three months in a refrigerator. It has to be transported and stored at 2C to 8C. At those temperatures, the vaccine can last at least six months.
How long will these vaccines protect against COVID-19?
It’s difficult to put a definite timeframe since all the coronavirus vaccines are new.
Dr Peter Marks, the head of the US Food and Drug Authority’s Centre for Biologics Evaluation and Research, said: It appears there’s a duration of protection against disease of at least several months. It’s probably at least on the order of four to six months. Some researchers expect the protection to last for years, but they aren’t certain.
If other protein-based vaccines are any indication, the Novavax vaccine can create memory B cells and memory T cells that retain information about the coronavirus for years to mount an immune response to a new infection.
Original news source Credit: gulfnews.com