ARS TECHNICA – A COVID-19 booster targeting two versions of the coronavirus in one shot offered stronger and broader protection than the current booster, which targets only one version, according to clinical trial results released this week by vaccine maker Moderna.
The results are preliminary and have not been peer reviewed or published in a scientific journal.
But Moderna touted the findings as evidence that bivalent or multivalent vaccines—those that target two or more versions of the virus in a single shot—are the way forward for COVID-19 boosters.
Moderna and other vaccine makers are on a mission to develop boosters that could restore the once extraordinarily high levels of protection that mRNA-based COVID-19 vaccines initially provided, while also protecting against future variants.
The first-generation mRNA vaccines were all designed to target the ancestral version of SARS-CoV-2 isolated in Wuhan, China—and they did so quite effectively, showing efficacy against symptomatic disease in the ballpark of 95 percent. But the virus has evolved into variants that can evade vaccine-derived protections.
As such, vaccine makers are testing variant-specific boosters as well as combination shots.
Moderna and Pfizer/BioNTech—joint makers of the other leading mRNA COVID-19 vaccine—swiftly announced plans for an omicron-specific vaccine in December, before the fast-moving variant swept the globe.
But so far, early animal data has suggested that a booster dose targeting only the omicron variant may not offer an advantage over the current vaccines at protecting against omicron.
While variant-specific vaccine trial data continues to come in, vaccine makers have also been working on combination shots … READ MORE.