"Trial Data Clear, Transparent...": Russian Scientists Defend Sputnik V

Russian scientists leading clinical studies for the Sputnik V COVID-19 vaccine have responded to claims of "serious concerns over interim results from phase 3 trials" by stressing their data meets "clear and transparent standards... considered sufficient for regulatory review and approvals".

Concerns over phase 3 studies - specifically data discrepancies, trial protocols, and the accuracy and quality of data from which conclusions were drawn - were raised by a group of scientists from universities in the United States, the Netherlands, Italy, France and Russia.

Their note, which also flags "problematic data in the published phase 1/2 results" was published Wednesday in the 'online first' section of international medical journal The Lancet. Among the points raised was a change in primary outcome - vaccine efficacy - recorded in September.

"Initially, the primary outcome was to be assessed after the first dose but the evaluation was postponed to after the second dose. The presented primary result (efficacy of 91.6%) is dependent on this change, but the reasons for the change have not been made public," the scientists wrote.

The scientists also flagged apparent absence of "crucial information, such as clinical parameters determining suspected COVID-19 (in trial participants), diagnostic protocols...", that are relevant in understanding how effective the vaccine is in protecting against the disease.

Finally, they also expressed concern over enrolment and randomisation of participants, and pointed to an apparent discrepancy in numbers shared with clinicaltrials.gov. Concern was also expressed over discrepancy in number of people vaccinate between days 10 and 20 of the study.

"Restricted access to data hampers trust in research... we invite the investigators once more to make publicly available the data on which their analyses rely...," the wrote.

In their reply the Sputnik V scientists said changes to trial protocol were made in November and revised documentation submitted to The Lancet in accordance with the rules.

They said primary outcome - i.e., vaccine efficacy - was "based on number of cases of COVID-19 in participants who received both doses". This is "consistent with primary outcome of other studies".

The Russian scientists also said data requested by their colleagues - diagnostic protocols and testing parameters - were available, in full, in the original article's appendix, and that questions over the numbers of trial participants were "simple typing errors that were formally corrected".

"... to date, safety and immunogenicity of Sputnik V has been confirmed in multiple studies... (including) in Argentina, where vaccination with Sputnik V began," they wrote in a note published Wednesday in the 'online first' section of international medical journal The Lancet.

"It is on this basis Sputnik V has received registration in 51 countries," the scientists said, adding that preliminary data showed an "appropriate safety profile" and pain at injection site, fever and muscle pain as the most common adverse events.

The Russian-made vaccine was last month also questioned by Brazil's national health regulator Anvisa, which said its decision was based on evidence the vaccine carried a live version of a common cold-causing virus -- information it said "was submitted by Sputnik V vaccine developers".

The decision prompted an international row, with Sputnik V saying it was "undertaking a legal defamation proceeding against Anvisa for knowingly spreading false and inaccurate information."

Sputnik V - with a declared efficacy rate of 91.6 per cent, was approved for emergency use in India on April 12, although it has yet to be rolled out. The delay, reports suggest, is due to mandatory quality tests on the first batch that landed in Hyderabad on May 1.

Vaccine shortage has hit India - which this morning reported over 3.6 lakh new Covid cases - hard, with limited production of Covishield and Covaxin - the two currently in use.

After appeals to the centre, which resulted in political rows, several states have now floated global tenders to import doses directly from manufacturers abroad.