Modern on Wednesday released preliminary results of an updated coronavirus vaccine targeting the Omicron variant, calling it “our main candidate” to act as a US booster shot in the fall.
The firm’s researchers tested a booster dose with the original vaccine, specifically targeting Omicron, which became effective last winter. They found that in those who had no previous evidence of coronavirus infection, the combination produced 1.75 times the level of antibody neutralization against Omicron as the existing modern vaccine alone did.
While these results may seem encouraging to them, many experts worry that the virus is evolving so rapidly that it is exceeding the ability to modify vaccines, at least until the United States relies on human clinical trials for results.
Moderna’s new results from a clinical trial involving 814 volunteers indicate that the updated vaccine produced significantly stronger immune responses against Omicron than the existing vaccine one month after the booster shot. Booster shots follow the previous three doses of Moderna’s vaccine.
But Omicron has been making subvarients for months, and some vaccine experts say the important thing now is how well a new booster formulation will protect against the latest subvarients, BA.4 and BA.5, not Omicron itself. First detected in South Africa earlier this year, these two submarines are now responsible for 13 percent of new cases in the United States and are spreading rapidly. According to some estimates, within a month they will surpass two more Omicron submarines, BA.2 and BA.2.12.1, which are currently in effect.
Moderna did not release any information on how the updated vaccine worked against BA.4 or BA.5. In a presentation Wednesday morning, Dr. Stephen Hodge, president of the firm, said researchers are still collecting data on them and other subvarients.
But he said a very small sample, isolated from other studies, suggested that antibody neutralization levels triggered by the updated vaccine were two to three times lower than those triggered by BAM.4 and BA.5 subvariets, compared to those triggered by Omicron. However he acknowledged that their numbers were not enough to defeat Ehud Olmert’s administration.
Moderna officials say they have not yet said whether the reconstituted vaccine will provide more long-term protection than the existing one, but they are hopeful that it is based on previous findings of a vaccine study reconfigured against a different variant released in April.
The new subvariant seems to have spread faster than previous versions of Omicron, and it could be better at evading the immune system’s defenses. It is unknown at this time what he will do after leaving the post. Dr. Anthony S. Fawcett, the White House’s chief medical adviser, said in an interview Tuesday that South Africa, where BA.4 and BA.5 are widespread, has “seen a slight increase in hospital admissions, but ICU use and mortality are really steadily lower.”
However, considering how rapidly the virus is changing, some vaccine experts say that it is more understandable to look at recent versions of the virus than to look for viruses that have already passed or will soon appear.
The problem is that Moderna and Pfizer – the makers of other major coronavirus vaccines in the United States – now do not have enough time to run more humane clinical trials and still make shots before the fall, while the Biden administration hopes to be able to. There will be a winter surge to offer an updated vaccine to deal with what public health experts have predicted.
This could force regulators to opt for updated vaccines based on information from laboratory tests and trials involving rats or other animals, rather than strong human tests. It is also possible that in the fall another new form of anxiety will emerge, further complicating the picture.
Advisers from outside the Food and Drug Administration will meet on June 28 to discuss which vaccine formulation will work best to facilitate the fall; Vaccine manufacturers say they need to start production soon.
“Of course, the final decision is always left to the FDA,” said Dr. Fawcett. “But what the FDA will probably do is keep as much iron in the fire as possible. And they may have to go back to alternative ways of making decisions, which is laboratory data and potential animal data. “
Asked if Americans would adopt a booster formulation without a long human test, he said, “Those who are really concerned about protecting themselves will do so.”
John Moore, a virologist at Weill Cornell Medicine in New York, said many healthcare professionals in the epidemic would feel comfortable switching to a different model to develop a coronavirus vaccine at this time, such as the one used to change the flu vaccine each year. Federal health officials say the combination of annual flu vaccines has been changed to meet new forms with minimal human testing.
Testing of the modern vaccine targeting Omicron began in late February. The average age of the participants was 57. All volunteers received three shots of Moderna’s existing vaccine – two shots, a booster dose given an average of eight months after the second shot.
About four and a half months after that first booster, 377 volunteers received a second booster with the existing vaccine, while 437 received a booster designed to work against Omicron. The updated booster has created a strong immunity in both those who have been infected with the virus before and those who have not.
Overall, those who received the updated booster had 59 percent more neutral antibodies than the existing booster, according to data published by Modern.
Antibodies are the body’s first line of defense against infection with coronavirus. Other diseases that also protect against Covid-19 have not been measured; Conducting these tests is much more complex and time consuming.
Dr. Paul Burton, Modern’s Chief Medical Officer, described the results as “very encouraging”. “We really feel that this is a fundamental turning point in our fight against this virus – one that we can adapt to,” he said.
But Dr. Moore says the increase in antibody neutralization to less than double that of existing vaccines is “only a moderate advantage.”
“Does this justify a change in the composition of the vaccine, in terms of cost and logistics and everything else involved?” He asked. That’s the decent thing to do, and it should end there.
Pfizer and BioNTech, its German partner, are testing an Omicron-specific vaccine and are expected to release their results soon.
In April, Modernna released preliminary results of a vaccine redesigned to attack the beta variant, which was first identified in late 2020. The firm says that this version of the vaccine is not only against Bitter, but also has a stronger immune response than the initial formulation. Also against the Delta and Omicron variants. Although Moderna officials said additional protection against Omicron had been in place for six months, they said they hoped an Omicron-specific vaccine would be a good candidate.