Preliminary data released by the company on Wednesday showed that its ommicron-targeted coronavirus booster candidate produced 1.75 times as many neutralizing antibodies against the winter version of omicron known as BA.1, compared to its existing vaccine. .
But the omicron variant has mutated so quickly that several new sub-variants have emerged that are even better at evading the immune system’s defenses. Two of those, known as BA.4 and BA.5, are now responsible for 13 percent of new coronavirus cases in the United States, the Centers for Disease Control and Prevention says in new estimates. It is unclear whether BA.4 and BA.5 will become dominant in the coming months or whether the population’s existing immunity to infections and vaccinations will slow its spread.
Biden administration officials have said they are preparing for a fall and winter wave that could lead to 100 million coronavirus infections and a potentially significant number of deaths, driven by ommicron subvariants. That makes it even more important that more effective vaccines are available, especially to protect the elderly and the most vulnerable.
Moderna executives said during a call on Wednesday that they are confident the updated vaccine will still provide additional protection against newer omicron subvariants, although researchers have tested the booster dose against BA.1. Even if the updated booster offers less protection against later ommicron subvariants than against BA.1, it will likely still be more effective against them than the company’s existing booster, said Moderna president Stephen Hoge.
“We are quite confident that this vaccine will provide an advantage even against the family of omicron subvariants,” Hoge said during a briefing interview with reporters.
Shortly after the ommicron variant was identified in South Africa late last year, Moderna said it was developing shots specifically designed to combat the variant. Pfizer and BioNTech announced the same plan, although they have not yet released data on their updated vaccine.
Data from the recent clinical trial, which involved 437 participants, showed that Moderna’s ommicron-targeting booster was likely to provide longer-lasting protection against variants a month later, compared to previous versions of its coronavirus vaccine, Moderna said.
The booster “was generally well tolerated,” with side effects similar to those of previous boosters, the company said.
The White House has been pressuring Congress for more than $20 billion for its response to the coronavirus for several months. Legislators have yet to approve new funding.
The official number of new daily coronavirus infections is slowly rising in the United States, although the actual numbers are believed to be much higher because so many people test themselves at home. The country registered a 38 percent increase in new cases last week, according to figures collected by The Washington Post, as protections against booster shots and previous infections wane and more people live their lives without masks.
Globally, new cases of coronavirus are still declining after the ommicron variant has caused tens of millions of new cases worldwide, increasing infections during the winter.
