As the Delta variant spreads, Pfizer seeks US authorization for COVID booster injections
The chief scientist of the drugmaker said on Thursday that Pfizer plans to require U.S. regulators to approve a booster dose of its COVID-19 vaccine within the next month. This is based on evidence that there is a greater risk of reinfection six months after vaccination and high levels of virality. spread. Infectious delta variation.
However, the US Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) stated in a joint statement that fully vaccinated Americans do not need to boost COVID-19 injections at this time.
Some scientists also questioned the need for enhanced injections.
Mikael Dolsten, Pfizer’s chief scientific officer, said that the recently reported reduced effectiveness of vaccines in Israel was mainly due to infections in people who were vaccinated in January or February. The Ministry of Health said that the effectiveness of the vaccine in preventing infections and symptomatic diseases fell to 64% in June.
“Pfizer vaccine is highly active against delta variants,” Dorsten said in an interview. But six months later, he said, “As predicted, as the antibodies weaken, there may be a risk of re-infection.”
Pfizer did not release the full set of data for Israel on Thursday, but said it would release it soon.
“This is a small data set, but I think the trend is accurate: after six months, given that delta is the most contagious variant we have seen, it will cause infection and mild disease,” Dorsten said .
The FDA and CDC said in their joint statement: “If it is scientifically proven that a booster dose is needed, we are ready to receive a booster dose.”
Dorsten said Pfizer’s own data from the United States showed that by the mid-1980s, the vaccine’s effectiveness against the spring variants circulating there declined after six months.
He emphasized that data from Israel and the United Kingdom show that even if antibody levels decrease, the effectiveness of vaccines against serious diseases remains around 95%.
The vaccine was developed by German partner BioNTech SE, and in a clinical trial conducted by the two companies last year, it showed 95% efficacy in preventing symptomatic COVID-19.
Dolsten said that early data from the company’s own research showed that the third booster injection produced 5 to 10 times higher antibody levels than after the second injection, indicating that the third injection will provide promising protection.
He said that many countries in Europe and other places have approached Pfizer to discuss the issue of enhanced doses, and some countries may start using them before obtaining potential authorization from the United States.
Dorsten said that he believes that booster injections are particularly important in older people.
Dr. Eric Topol, professor of molecular medicine and director of the Scripps Research and Translational Institute in La Jolla, California, said the decision based on weakened antibody protection ignores the role of other important parts of the immune response, including memory B cells, which can be challenged by the virus. Manufacture antibodies on demand at any time.
“You need better research to assert this. It’s not just about neutralizing antibodies,” Topol said.
Some scientists question whether boosters are needed
Pfizer has previously stated that people may need a booster dose, but some scientists question when or if a booster dose is needed.
Pfizer plans to soon launch a placebo-controlled efficacy trial with 10,000 participants. Dolsten said the study will be conducted throughout the fall, which means it will not be completed before the company submits documents to the Food and Drug Administration.
Dr. William Schaffner, a vaccine expert at Vanderbilt University Medical Center, said that even if Pfizer’s booster succeeds in obtaining FDA authorization, this is only the first step. The booster still needs to be reviewed and recommended by CDC consultants.
“In any case, this is not automatic,” he said. Schaffner said that in fact, most of the public health bandwidth in the United States is still focused on encouraging Americans to get the first and second doses of vaccines.
Since the booster will drive increased demand for vaccines when most parts of the world are still unvaccinated, Dorsten said that Pfizer is looking for ways to increase production.
Its goal is to produce 3 billion doses this year and 4 billion doses next year. Dolsten declined to give a precise forecast of how much the company can increase the dose, but said, “We can increase it by 1 billion times in 22 years.”
Dolsten also said that Pfizer and BioNTech are designing a new version of the vaccine against the Delta variant, but said that the two companies do not believe that the current version needs to be replaced to combat the variant.
Pfizer expects that the COVID-19 vaccine will be the main source of revenue for many years, and it expects sales of the vaccine to reach $26 billion in 2021. According to the United States, by 2025, global spending on COVID-19 vaccines and booster injections may reach US$157 billion in health data company IQVIA Holdings.