These Vaccines Will Take Aim at Covid—and Its Entire SARS Lineage

In the early days of the Pandemic, a bout with Covid-19 seemed to ward off another infections. New viral variant are able to dodge that hard-earned protection. Keeping track of those variant and how they escape immune protection is an exhausting game that scientists would like to eradicate with a new vaccine.

Several routes have been tried by scientists. Moderna and Pfizer are trying to create updated boosters that target the most recent variant of the Omicron virus by using the existing Covid mRNA vaccines. The most ambitious route is to create a vaccine that targets the entire coronaviruses family, including the merbecoviruses that cause MERS, the embecoviruses that cause ordinary colds, and the sarbecoviruses that give rise to both Covid and

The vaccine that would attack the sarbecoviruses and all of its future offspring is the middle path. Some of the candidates have been tested in animals and one is in a small clinical trial. The sarbecoviruses have similarities that could be used to fight their entire family.

Alex Cohen is a researcher at Caltech who is working on a vaccine that targets parts of the sarbecoviruses that are very conserved. He wants this protection to be achieved with one type of vaccine or immunization.

Some of the candidates that are being developed are shown here.

There are vaccines with mosaic particles.

Cohen works in the department of biology and biological engineering at Caltech, where a paper on their candidate was recently published in the journal Science, showing protection in monkeys and mice against multiple sarbecoviruses. Their vaccine is built on a small, cage-like proteins ball.

Many sarbecoviruses have the same target that they want the immune system to attack. The Caltech lab chose a part of Covid's famous spike protein which helps the virus enter andinfecting a cell. Although some parts of the binding site may change as new versions emerge, others remain the same. There are a few differences between the Delta and Omicron versions. If you can encourage the body to generate the antibodies that target those shared regions, they can protect against many different variations.

In order to come up with this plan, the team studied the antibodies from patients who had previously been exposed to Covid. A model of the spikeprotein is about the size of a woman's head, so it's very not to scale. She pointed to a region at the tips of theRBD that was blocked by potent antibodies that were isolated from people who were HIV positive. They didn't work as variant came along.