Alastair grant / AP
A new type of COVID-19 vaccine could be available as early as the summer.
It is what is known as a Protein subunit vaccine. It works a little differently than the current vaccines approved for use in the United States, but it is based on well-understood technology and does not require special refrigeration.
In general, vaccines work by showing people’s immune systems what looks like the virus but actually isn’t. Think of it as a warning; If the real virus ever shows up, the immune system is ready to suppress it.
In the case of the coronavirus, this “something” is one of the proteins in the virus – the spike protein.
Johnson & Johnson, Moderna, and Pfizer vaccines contain genetic instructions for the spike protein, and it is up to the cells in our bodies to make the protein themselves.
The first available protein subunit Covid-19 vaccine will likely come from the biotech company. Novavax. Unlike the three vaccines already approved in the US, it contains the spike protein itself – it doesn’t need to be made, it is already made – along with an adjuvant that boosts the immune system’s response to make the vaccine even more protective.
Protein subunit vaccines Made this way has been around for a while. There are vaccines on the market against hepatitis B and whooping cough based on this technology.
A major test of the effectiveness of the Novavax COVID-19 vaccine that was conducted on tens of thousands of volunteers in. was carried out the United States and Mexico, is nearing completion. Dr. Gregory Glenn, President of Research and Development at Novavax, told an audience at a recent webinar hosted by the International Society for Vaccines that “we expect to see regulatory filings in the UK, US and Europe in the third quarter.”
Turn factories into factories
To make the virus protein, Novavax uses huge vats of cells grown in the laboratory. But there is another way to make the protein: put plants in a greenhouse to do it.
This is the Canadian biotech company’s approach Medicago.
The plants used are related to the tobacco plant, and have been modified to include the genetic instructions for making the viral protein.
The plants are doing something very valuable – they form a lipid shell that surrounds a bunch of viral proteins, with the proteins sticking out.
“The plant will assemble the protein in a shape and form that looks like the virus,” says Nathalie Landry, Medicago Executive Vice President for Scientific and Medical Affairs. “So if you look at a picture of it, it looks like a virus, but it cannot cause disease. But if [it’s] Injected as a vaccine, your body will produce a good immune response. “
Early studies suggest that Medicago’s vaccine candidate is doing just that, and the company is so confident with these results that it has already begun a large human trial that could involve up to 30,000 volunteers in 11 countries.
Landry admits that Medicago COVID-19 vaccine development has lagged behind others.
“We’re a straggler, but we’re coming,” she says.
Another latecomer is the pharmaceutical giant Sanofi. His protein subunit vaccine against the coronavirus is also grown in cells in the laboratory.
Late last year, the company was preparing to conduct a large study on the vaccine’s effectiveness when initial results showed in a smaller group of people that it did not elicit a protective immune response.
“Especially in the elderly in this study, it wasn’t as immunogenic as it should be,” says Dr. Paul Göpfert at the University of Alabama at Birmingham, who was one of the researchers involved in these early studies. He says the problem turned out to be an incorrect calculation of the vaccine dose administered.
“So instead of giving 10 micrograms of the dose, they actually gave one microgram,” says Goepfert.
Sanofi has corrected this problem and repeated the early studies with good results. The company is now recruiting volunteers into a large efficacy study.
Goepfert says it is good if all of these vaccines reach the consumer. But that alone will not solve the problem of vaccination.
Why? “Because the vaccines we have now exceed our wildest dreams, they are effective,” he says. “And right now I live in a state where I just get frustrated by how slow our vaccine uptake is.”
Goepfert lives in Alabama. According to the latest numbers of the Centers for Disease Control and Prevention, only Mississippi has a lower vaccination rate per capita.