Sept. 10 (UPI) -- An international group of scientists, in an open letter, have questioned Russian research that went into analyzing the COVID-19 vaccine announced last month by the Kremlin.
The group of 29 mostly European scientists, led by Temple University biology professor Enrico Bucci, said in the open letter they have noted several instances of apparent duplication in reports of the "Sputnik V" vaccine's antibody response in human volunteers.
For example, all nine volunteers exposed to one formulation of the vaccine, they said, appeared to have identical antibody titres at 21 and 28 days. The same was noted in seven of nine volunteers who were given another formulation.
Also, the scientists said, they noted duplicate values for different patient groups.
"On the ground of simple probabilistic evaluations the fact of observing so many data points preserved among different experiments is highly unlikely," the letter states.
"Among the [different] groups of nine patients, testing completely different things, you see exactly the same numbers," Bucci told The Moscow Times. "It's highly improbable to observe such a huge number of duplications.
"It's like if you throw a dice and you get exactly the same sequence of numbers several times -- it's highly improbable."
The Russian research was published last week in The Lancet medical journal for peer review, a key step in the approval process for any vaccine.
In their letter, the scientists also expressed concern about a lack of original data presented by Russian researchers in their Lancet article. The scientists, from the Gamaleya National Center of Epidemiology and Microbiology in Moscow, had reported the vaccine proved safe and effective at producing antibodies in more than 70 healthy adults participating in a pair of early-stage trials.
"The extreme public interest and expectations for an effective vaccine are understandable. However, the very same reasons should motivate the scientific community to pay even more attention to the scientific evidence and the underlying data, and it is thus of utmost importance that they are fully available for close scrutiny," they wrote.
"While the research described in this study is potentially significant, the presentation of the data raises several concerns which require access to the original data to fully investigate."
Kirill Dmitriev, CEO of the Russian Direct Investment Fund, which has helped fund development of the vaccine, said the published results are "the final answer in the round of questions directed against Russia."
Moscow announced last month the Sputnik V vaccine had been the world's first COVID-19 registered for use, and Russian President Vladimir Putin said he'd even given it to one of his daughters.
The vaccine has been criticized by most health experts, however, because no data had been published and no late-phase testing had been done. The data published in The Lancet last week was the first that was made available about the vaccine, and its appearance in the journal is a key step in the peer review process that's necessary for any potential medical breakthrough.