Experts believe that there is nothing ominous in the question about Oxford vaccine trial data.

London -Wednesday AstraZeneca and Oxford University admitted manufacturing errors that questioned the preliminary results of the experiment COVID-19 vaccineHowever, an outside expert told CBS News that there was “nothing ominous” in the way human clinical trial data was collected, and that the vaccine was considered safe and effective and approved for use. I’m optimistic.

A statement explaining the error explains why the company and the university described the shots as “very effective” and some study participants did not get as much vaccine as they expected in the first two shots. I didn’t mention it.

The group of volunteers who received the low dose appeared to be much better protected than the volunteers who received the full dose twice. According to AstraZeneca, the vaccine is 90% effective in the low dose group. The vaccine appeared to be 62% effective in the group that received two full doses.

Together, the pharmaceutical company said the vaccine appeared to be 70% effective, but the way the results were reached and reported led to questions from some experts.

Partial results published on Monday are from large ongoing studies in the United Kingdom and Brazil designed to determine the optimal dose of vaccine and to investigate its safety and efficacy. In volunteers, multiple combinations and doses were tried. They were compared to others who were given a meningitis vaccine or saline shot.

Was it a mistake?

Before they begin their research, scientists elaborate on every step they take and how they analyze the results. Deviations from that protocol can make the result a problem.

Oxford University said in a statement to CBS News Thursday that the dose was the same in all three study stages, but was the highest dose in the “results of manufacturing process differences” in the Phase 3 study. The method used to measure the concentration of vaccine in vials far overestimated the dose of the new batch, “resulting in half the dose of vaccine being given as the first dose.”

The university said it had discussed the issue with UK drug regulators and agreed to complete the late trials in two separate subgroups.

Oxford said in its statement that the method of measuring vaccine levels was adjusted to avoid further discrepancies, “and we can guarantee that all batches of vaccine are now equivalent.” ..Thursday, AstraZeneca CEO Pascal Soriot Told Bloomberg News The company said it needed to conduct a new trial, but he suggested that the high efficacy of the vaccine would reduce the number of patients required for the new trial, which would allow it to be conducted more quickly.

How is the result?

Some experts find it difficult for a relatively small number of people in the low-dose subgroup (2,741) to know if the 90% efficacy seen in that group is genuine or statistical habit. I say that I am doing it. A total of 8,895 people received the full dose twice, with a low efficacy of about 60% in that group.

Another factor: No one in the low dose group was 55 years or older. The youth of the participants in the low-dose group may have shown it more effectively than the size of the first dose, as younger people tend to have a stronger immune response than older people.

Peer-reviewed earlier this month Analysis of Oxford Phase 2 study data published in The LancetThe vaccine “has similar immunogenicity in all age groups” after two full doses, and in fact “Elderly people are more tolerant Than young adults “

The trial enrolled 560 adults, including 240 over 70 years of age.

Older patients are known to be at very high risk of serious illness and death from the coronavirus. They are the patients most likely to fill an overstretched ICU ward and are designated to be vaccinated first.

Why do lower doses work better?

Oxford researchers say they are uncertain and are working to find out why, but there are some ideas.

Sara Gilbert, one of the Oxford scientists leading the study, said the answer was probably related to providing the exact right amount of vaccine to provoke the best immune response. It was.

“I think you need the amount of Goldilocks. Don’t be too little, not too much. Too much can also reduce the quality of the response. You need the right amount and you’ll hit a little. Perfect for the first time. I miss it when I’m trying to go quickly to get something. “

Professor Adrian Hill, director of the Jenner Institute at the University of Oxford, who developed the vaccine, explained this “Goldilocks” theory in detail to CBS News’ Charlieda Gata, saying that the first dose of the vaccine would provoke an immune response to both. Stated. Coronavirus antigens protect someone from infection and the virus itself.

“If you give a large dose first and then a large dose, the second dose will not work because of the immunity caused by the first dose,” he said. “Half the first dose is very likely to interfere with anti-vector immunity, so the second dose works more effectively.”

Hill emphasized that this explanation has not yet been proven. “But this will be considered over the next few weeks and months.”

Where are you going from here?

AstraZeneca in the United States said in a call to reporters Tuesday that U.S. officials are trying to determine what immune response the vaccine caused, said Monsef Slawi, who heads Operation Warpspeed, a U.S. coronavirus vaccine program. A dose subgroup that may decide to modify the Zeneca study to include half.

“There are a lot of variables we need to understand. We want it to be based on data and science,” Slawi said.

Full details of the test results will be published in medical journals and provided to UK regulators to allow them to decide whether to approve the vaccine distribution.

These reports include a detailed breakdown, including demographics and other information about who got sick in each group, and provide a more complete picture of the effectiveness of the vaccine.

“There is nothing ominous”

Even AstraZeneca and Oxford will admit that more data analysis is needed to make a definitive decision on how well the vaccine works and what dose should be used, but at Imperial College London. Immunology professor Danny Altman told CBS News on Thursday that he is not overly concerned about the errors behind the trial data.

Unrelated to the Oxford vaccine and equally optimistic about other major vaccine candidates in Pfizer and Moderna’s final-stage trials, Altman said, “Ominous or unsafe, or the credibility of their research. There is nothing that impairs sex. ” , For example.

Rather than misrepresenting test data, Altman describes the Oxford team’s preliminary success characteristics and their scrutiny, with the unprecedented speed of the vaccine development process in this pandemic and the unprecedented public. I think it is due to the interest of.

“This puts a very harsh spotlight on the failures and pitfalls of’press release science’. This is what almost everyone is crazy about due to the current climatic conditions, “he told CBS News.

He said preliminary clinical trial data, which the world devours and is keen to understand, will usually be judged in long manuscripts for peer review.

“We are not used to evaluating data in real time in short press releases,” he said. Asked if the reason and details of the half-dose regimen should be fully disclosed in a press release sent by Oxford on Monday, he said: “It pays for a simplified sound bite process. It’s a price. “

And most importantly, based on the available data, Altman hopes that the Oxford vaccine will not only be widespread, but it will not be the only one.

“My assumption was that we probably saw very powerful and large peer-reviewed datasets from Pfizer, Moderna and Oxford, and I think Novavax, too,” he said. “Then you have to go through them with a fine comb. I think they are all very good. I think they are all in the right stadium. I think they can all save us bacon.”