What happened

Shares of Moderna (MRNA 1.58%) rose 3.3% on Monday after health regulators in the U.K. authorized the biopharmaceutical leader's bivalent COVID-19 vaccine booster for use in adults. 

So what

Moderna's updated vaccine targets the original coronavirus strain and the currently fast-spreading omicron variants. On Monday, the Medicines and Healthcare products Regulatory Agency (MHRA) said the new bivalent booster meets its "standards of safety, quality, and effectiveness." 

Additionally, the regulator said clinical trial data showed that the vaccine produced "a strong immune response against both omicron (BA.1) and the original 2020 strain" while also eliciting a "good immune response against the Omicron sub-variants BA.4 and BA.5." Importantly, no serious safety concerns were observed during the trial.

In a separate press release, Moderna noted that a phase 2/3 study demonstrated the vaccine booster's ability to generate a roughly eightfold increase in neutralizing antibody response against omicron (BA.1) compared to its original booster shots. The company also said the new booster produced "potent" neutralizing activity against the currently dominant BA.4 and BA.5 omicron strains.

"The first generation of COVID-19 vaccines being used in the U.K. continues to provide important protection against the disease and save lives," MHRA chief executive Dr. June Raine said. "What this bivalent vaccine gives us is a sharpened tool in our armory to help protect us against this disease as the virus continues to evolve."

Now what 

If Moderna can develop booster shots that safely and effectively protect against emerging coronavirus mutations, it could go a long way toward helping to bring about the end of the pandemic. The U.K.'s favorable regulatory decision suggests the biotech's messenger RNA-based platform -- which enables Moderna to quickly tailor its drug candidates for specific pathogens -- is well suited for the task. That bodes well for Moderna's long-term drug-development success, as well as its ability to generate further gains for its investors.