Twenty-six scientists, most of whom work at Italian universities, signed an open letter challenging the reliability of the data provided in the early-stage test results of the Russian COVID-19 vaccine dubbed 'Sputnik-V.'
Addressing the editor of The Lancet, the peer-reviewed international medical journal in which Moscow's Gamaleya Institute reported its early-stage test findings, the scientists said they saw trends in the data that seemed "extremely unlikely."
The letter, published on one of the signatories' personal blog page, said the findings of the Phase I/II trials showed several participants displaying similar levels of the antibody.
"The possibility of having so many data points preserved between different experiments is highly unlikely on the basis of simple probabilistic evaluations," the open letter said.
However, the scientists said that they were based on summaries of the results of the Russian test, published in the journal, rather than the original data itself.
"In the absence of the original numerical data, no conclusions can be drawn on the reliability of the data provided, in particular with regard to the apparent duplications detected," the letter said.
The critique was rejected by the Gamaleya Institute, that developed the vaccine.
"The published results are genuine and correct and have been reviewed by five reviewers at The Lancet," Denis Logunov, the institute's deputy director said.
He said his institute had provided The Lancet with the whole body of raw data on the results of the tests.
"We presented the data generated (by the trial) directly, not the data that should please Italian experts," Logunov said.
His research was defended by Naor Bar-Zeev, deputy director at John Hopkins Bloomberg School of Public Health, who peered the Russian data.
"Science must maintain a balance between uncertainty, skepticism and confidence. This trust is borne out by plausibility, repeatability and falsifiability.”
"The results are possible, and not very different from those seen with other products vectorized with AdV," he said.
The researchers presented more information than required for the analysis and answered his questions "intelligently and in a matter-of-fact manner that was confident but understated."
"In the end, I saw no reason to doubt the legitimacy of these findings over those that I have read and reviewed. But one can't know of course, "he said in an email.
A Lancet spokeswoman said the journal had invited the authors of the study to answer the questions posed in the open letter. He was closely following the situation, she said.
Russia published results on Friday of its Phase I/II trial, which included 76 participants and was conducted in June-July this year. Participants developed a positive immune response and no serious side effects, the study’s authors said.
On 26 August a Phase III trial was conducted, involving 40,000 participants. Health minister Mikhail Murashko said about 31,000 people have already subscribed to take part.