A study suggested that the updated booster shot produced higher levels of neutralizing antibodies against the Omicron subvariants BA.4 and BA.5 than the first booster, the company said.
A new study by Moderna suggests that its updated coronavirus booster strengthens a key component of the immune system’s defense against the Omicron subvariant that accounted for most infections in the United States in recent months.
The company announced the findings in a news release on Monday. The underlying data has not yet been published or peer-reviewed, but it has been reviewed by federal regulators.
The data indicates that Moderna’s new booster generates significantly higher levels of neutralizing antibodies against the subvariant, BA.5, and another Omicron subvariant, BA.4, than the previous booster, the company said. The federal government replaced the original boosters from Moderna and Pfizer-BioNTech with updated shots in September.
The study is the largest to date of one of the new shots, comparing hundreds of people who received either the updated booster or the original one.
While federal officials said they were heartened by the findings, the data underscored the problem in chasing a virus that invents new defenses against immunization faster than vaccine manufacturers can design and produce modified shots. The government is confronting a crowded landscape of fast-moving Omicron subvariants that threaten to evade the population’s immunity from vaccinations and previous infections.
When the government first decided on the makeup of the new booster this past summer, it targeted BA.4 and BA.5. The latter of those subvariants was responsible for a vast majority of infections in the United States in the summer and early fall, and it still accounts for about 30 percent of cases. Another fast-growing Omicron subvariant, BQ.1.1, could become dominant by Thanksgiving, said Dr. Stephen Hoge, the president of Moderna.
Dr. Hoge said the company’s lab tests suggested that the new booster also produced robust levels of antibodies against that surging subvariant, although far fewer than against BA.4 and BA.5. He cautioned that the BQ.1.1 tests were preliminary and involved only 40 participants.