New research shows that Moderna’s Covid-19 vaccine may provide longer-lasting protection than Pfizer’s vaccine because the government and scientists argue over who Need booster The lens and when.
Recent studies have shown that, compared with BioNTech/Pfizer’s competitor mRNA vaccines, Moderna jabs can cause a stronger immune response and its effects will weaken more slowly.
Moderna’s chief medical officer Paul Burton said that a series of “extremely reassuring” studies in the past few weeks showed that Moderna’s injections have “long-term” effects, can resist Delta variants, and can even help people with compromised immune systems.
A study published this week in the Journal of the American Medical Association found that Belgian medical staff who received Moderna injections had more than twice the number of antibodies two months after the second injection as those who received Pfizer injections.
Deborah Steensels, one of the authors of the study, said that higher antibody levels shortly after vaccination should lead to longer-term protection and greater resistance to Covid variants. Although scientists can only count all antibodies, not the gold standard neutralizing antibodies, she said this correlation is sufficient to support this theory.
“For all vaccines, the effectiveness of protecting people from serious diseases and mortality is very high, which is the main goal of vaccines,” she said. “But our hypothesis is that in order for protection against mild diseases to last longer, you need to obtain higher antibody titers after vaccination.”
Another study by the University of Virginia this week found that people who received Moderna injections had more antibodies than those who received Pfizer, and the difference was more pronounced in the elderly. These findings echo the results of a draft paper last month by University of Toronto researchers assessing the immune response of residents in long-term care facilities.
Some scientists believe that the Moderna jab can last longer because its mRNA dose—the genetic code that teaches the immune system how to recognize the coronavirus spike protein—is three times that of Pfizer. Another factor may be the time interval between the two doses. Moderna recommends 4 weeks, while Pfizer recommends 3 weeks.
Eric Topol, director of the Scripps Research and Translation Institute, said that in countries with long gaps such as the United Kingdom and Canada, the new coronavirus vaccine seems to be more effective than in the United States and Israel, because the United States and Israel have been Stick to the schedule for 3 trials.
“I think the rush to complete the experiment… exacerbated the recession,” he said.
Pfizer said its vaccines are still “very effective”, including in responding to mutations and preventing serious illnesses and hospitalizations.
Antibody research provides a reference for other “preprinted” papers that have not yet been peer-reviewed. These papers show that compared with Moderna, there are more breakthrough infections in people vaccinated with Pfizer.
Studies in the United States and the Mayo Clinic in Qatar have shown that Moderna vaccines are more effective, but because Pfizer vaccines are usually distributed earlier, there may be more time to weaken or give more vulnerable ones.
These studies show that with the emergence of Delta variants, the efficacy has dropped sharply. But early follow-up studies of the Phase 3 trial showed a similar pattern: Pfizer’s effectiveness against symptomatic infections dropped to a low-to-80% level after four to six months, while Moderna declined after five to six months. To 93%.
Other vaccines may also last longer than Pfizer’s. Two studies have shown that the effectiveness of the Oxford/AstraZeneca vaccine decreases more slowly than Pfizer’s, albeit at a lower initial rate.
Researchers at the University of Oxford had nothing to do with the university’s vaccine development and used data from the UK National Bureau of Statistics. They found that the efficacy of Pfizer injections against symptomatic infections was almost halved within four months, while the protective effect of AstraZeneca declined. Much slower.
This model is supported by data released by Zoe’s Symptom Research App last week. The efficacy of Pfizer dropped by 14 percentage points to 74% within five to six months, while the efficacy of AstraZeneca dropped by 10 percentage points to 67% after four or five months.
Scientists say this may be because Adenovirus Compared with mRNA, the Oxford vaccine lasts longer in the body, giving the immune system more time to respond. Johnson & Johnson, which also uses adenovirus, said that 8 months after vaccination, neutralizing antibodies in the body are actually higher than 29 days after vaccination.
“We think Pfizer is the bee’s knee, but it may wear out a little bit faster,” said Tim Spector, co-founder of Zoe and a professor at King’s College London.
But he cautioned that we have no conclusive evidence to distinguish vaccines, and key data will be released in the next six months.
Paul Hunter, an infectious disease expert at the University of East Anglia, warns against over-reliance on studies that may be just a “random fluke”. “These unexpected discoveries do appear frequently in epidemiology,” he said.
All studies use so-called “real world evidence” collected outside of experimental conditions. Cornell University virologist John Moore said that the key question is whether the populations vaccinated with each vaccine are comparable, because local factors such as the priority of each vaccine may confuse the results.
“Is this a real apple-to-apple comparison, or is there an orange or two crawling in it?” he said. “What we have seen so far should not mean that the promotion policies of the two mRNA vaccines are any different.”
Investors have yet to price the difference in vaccines in an unusual market where politicians are in control of their pockets, and vaccines are still in short supply.
Moderna and Pfizer’s booster plans are still advancing simultaneously. Both companies are developing vaccines for the Delta variant just in case, and have submitted data for the third dose to the U.S. Food and Drug Administration in recent weeks.
The third jab increases the antibody level. Pfizer said that people who received the booster at least six months after the second vaccination had 5 to 10 times more antibodies than the first two vaccinations. Moderna submitted data on Wednesday, claiming that the additional half of its vaccine dose is still more than Pfizer’s mRNA, resulting in antibody levels “significantly higher” than those found in initial trials and preventing mutations including Delta.
A vaccine that needs to be re-vaccinated more frequently may be a boon for investors, providing Regular income stream — A potential conflict of interest has made some scientists cautious about the company’s initial booster.
Topol of the Scripps Research Translational Institute said that he found Pfizer’s initial push to boost injections was “really strange” because there seemed to be no evidence that additional injections were needed, which could make the company “earn billions of dollars”. But now, with more data from Israel, he believes that these data will be needed at least among people in their 60s.
Credit Suisse analyst Jo Walton said that it is too early to conclude that there are any significant differences in the efficacy of Covid-19 vaccines, and it is certainly too early to Have any market impact.
She believes that governments are trying to ensure as many doses as possible in the short term to deal with booster campaigns, potential plans to vaccinate children, and the threat of mutation.
She said: “The government’s choice is zero: they have to get everything they can get with reasonable supply visibility.”
Evercore analyst Jon Miller said that the difference in vaccines has not been “convincingly proven” and the “horse racing” between Moderna, Pfizer and AstraZeneca has not promoted their stocks.
On the contrary, he said, investors are worried that as the Delta spread and the number of cases rise, the weakening of effectiveness will lead to a lockdown. “People are more worried about the overall durability of stopping the vaccine altogether.”