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Revised Moderna Vaccine Works Better Against Omicron, Trial Proposal


modern announced the first results on Wednesday On an updated coronavirus vaccine targeting the Omicron variant, he called it our “pioneer candidate” for the fall to serve as the US booster.

The firm’s researchers tested a booster dose that combined the original vaccine with a targeted vaccine specifically against Omicron, the variant that became dominant last winter. They found that among those without evidence of previous coronavirus infection, the combination produced 1.75 times more neutralizing antibodies to Omicron than the current Moderna vaccine did alone.

While these results may seem encouraging on their faces, many experts worry that the virus has evolved so quickly that it has outstripped its ability to replace vaccines – at least as long as the United States relies on human clinical trials for results.

Moderna’s new findings from a clinical trial involving 814 volunteers show that the updated vaccine produced a significantly stronger immune response to Omicron than the current vaccine one month after the booster vaccine was given. The booster shots followed the three previous doses of Moderna’s vaccine.

But Omicron has been producing sub-variants for months, and some vaccine experts say what matters now is how well a new booster formulation will protect not against Omicron itself, but against its latest sub-variants BA.4 and BA.5. These two subvariables were first identified in South Africa earlier this year. now accounts for 13 percent of new cases in the United States and it is spreading fast. By some estimates, they could outrun the competition within a month. two other Omicron sub-variants BA.2 and BA.2.12.1currently dominant.

Moderna has not published any data on how the updated vaccine works against BA.4 or BA.5. The head of the firm, Dr. Researchers are still collecting data on this and other subvariables, Stephen Hoge said in a presentation Wednesday morning.

But a very small sample, along with other isolated studies, suggested that the neutralizing antibody levels triggered by the updated vaccine were two to three times lower against the BA.4 and BA.5 subvariants compared to Omicron, he said.

Moderna’s researchers cannot yet say whether the reconstituted vaccine will provide more lasting protection than the current vaccine.

The newest sub-variants seem to be spreading faster than previous versions of Omicron and may be better at evading the immune system’s defenses. It is unclear whether they cause more severe disease. Chief medical adviser to the White House, Dr. Anthony S. Fauci said in an interview Tuesday: South Africa where BA.4 and BA.5 are common“It has seen a slight increase in hospitalizations, but ICU use and deaths remain really consistently low.”

In any case, given how quickly the virus mutates, some vaccine experts say it makes more sense to target the latest versions of the virus rather than the already passed or upcoming forms.

The problem is that Moderna and Pfizer, the makers of the other main coronavirus vaccine in the United States, still don’t have enough time to conduct more human clinical trials and produce a vaccine before the decline the Biden administration hopes to achieve. presenting an updated vaccine to predict a winter wave, according to what public health experts predict.

This could force regulators to choose updated vaccines based on data from laboratory testing and trials involving mice or other animals, rather than robust human trials. It is also possible that a new variant or alarming sub-variant will emerge in the fall.

external consultants to the Food and Drug Administration, will meet on June 28 discussing which vaccine formulation will work best as a fall accelerator; There are vaccine manufacturers Said they should start production soon.

Dr. “Of course, the final decision is always left to the FDA,” said Fauci. “But what the FDA will probably do is keep as many irons on fire as possible. And they may need to go back to alternative decision paths that have lab data and possible animal data.”

When asked if Americans would accept a booster formulation without lengthy human trials, he said, “People who are really very concerned about protecting themselves will agree.”

Moderna’s vaccine trial targeting Omicron began in late February. The average age of the participants was 57 years. All volunteers received three shots—two shots—of Moderna’s current vaccine, followed by a booster dose an average of eight months after the second shot.

About four and a half months after this first booster, 377 volunteers received a second booster with the current vaccine, while 437 volunteers received the booster designed to work against Omicron. The updated booster produced a stronger immune response among both those who were previously infected and those who were not.

Overall, those who received the updated booster had 59 percent higher levels of neutralizing antibodies than those who received the current booster, according to data published by Moderna. Antibodies are the body’s first line of defense in preventing coronavirus infection. Other immune responses that also defend against Covid-19 disease were not measured; performing these tests is much more complex and time consuming.

Moderna’s chief medical officer, Dr. Paul Burton described the results as quite encouraging. “We really feel that this is some kind of fundamental turning point in our fight against this virus – we can adapt to a variant,” he said. “It works.”

But a less than two-fold increase in neutralizing antibodies over the current vaccine is “only a modest benefit,” said John Moore, a virologist at Weill Cornell Medicine in New York.

“Does this justify changing the vaccine composition, given the cost, logistics, and everything else involved?” she asked. “The discussion will be about that.”

German partners Pfizer and BioNTech are also testing an Omicron-specific vaccine and are expected to announce their results soon.

Moderna in April published preliminary results It’s on a reconstructed vaccine to attack the Beta variant, first detected in late 2020. The firm later said that the combination provides a stronger defense not only against Beta, but also against Delta and Omicron variants. But officials said they expected an Omicron-specific vaccine would make a better candidate.



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