Russia’s vaccine diplomacy suffered a setback on Thursday when Slovakia, one of the few countries in Europe to order its Sputnik V coronavirus vaccine, said that the doses it purchased differed from a version reviewed favorably by a respected British medical journal.

A statement by Slovakia’s drug regulator questioning the Russian vaccine suggested potentially serious quality-control problems in the manufacture of Sputnik V and threatened recent progress made by Russia in winning acceptance for its product.

That progress has rested largely on a peer-reviewed article published in The Lancet in February that gave the Russian vaccine a thumbs-up. It said that Sputnik V had an 91.6% efficacy rate against COVID-19, an endorsement that Moscow has used to raise confidence in the vaccine and strengthen the Kremlin’s hand in vaccine diplomacy.

Slovakia’s regulator, the State Institute for Drug Control, however, said in a statement that vaccine batches imported into the East European country did “not have the same characteristics and properties” as the version of Sputnik V reviewed by The Lancet.

The Russian Direct Investment Fund, a sovereign wealth fund that financed Sputnik V’s development and has spearheaded a push for its use abroad, did not address the substance of the Slovak agency’s statement but dismissed it as “disinformation” and “fake news.” In a series of dismissive messages on Twitter, the fund accused the state regulatory agency of carrying out an “act of sabotage,” claiming that Slovakia had violated the terms of its contract and demanding that the doses be returned.

The dispute follows a raucous political battle in Slovakia that began last month when the prime minister, Igor Matovic, who was last week forced to step down, announced that he had negotiated a secret deal with Russia for 200,000 Sputnik V doses. The deal outraged fellow members of a fragile coalition government, who accused Matovic of succumbing to a Russian “tool of hybrid war” and dividing the European Union, of which Slovakia is a member.


Matovic, who traded jobs last week with the finance minister to try and save the government from collapse, met in Moscow on Thursday with Kirill Dmitriev, the head of the Russian Direct Investment Fund.

The fund, in a message posted on Twitter, said it “remains committed to assisting the people of Slovakia with vaccination by Sputnik V.” In another tweet, however, the fund said it had sent a letter on April 6 asking Slovakia “to return the vaccine due to multiple contract violations so that it can be used in other countries.”

The European Union’s regulator, the European Medicines Agency, has so far declined to approve the Russian vaccine for use and only two members of the bloc, Hungary and Slovakia, have placed orders for Sputnik V. Serbia, which is not a member of the bloc, has also ordered Sputnik V and begun using it in a mass inoculation program that has been far more successful than the stumbling efforts of most European Union states.

Sputnik V is manufactured at seven locations in Russia, and also at plants in India and South Korea. A number of other countries have signed manufacturing contracts, including Brazil, Turkey and Serbia. Russia has consistently delivered fewer doses of the vaccine than initially promised, suggesting glitches in manufacturing. Producing vaccines at scale is a difficult process and ramping up production has presented problems for Western vaccines, too.

Noting that about 40 countries are using or scheduled to use the Russian vaccine, the Slovak regulatory agency asserted that “these vaccines are only associated by the name.” That raised questions about deviations from the formula reviewed in The Lancet.

“The comparability and consistency of different batches produced at different locations has not been demonstrated,” the Slovak regulator said. “In several cases, they appear to be vaccines with different properties (lyophilisate versus solution, single-dose ampoules versus multi-dose vials, different storage conditions, composition and method of manufacture).”


The Slovak statement could damage Russia’s efforts to establish Sputnik V as a reliable brand. It could also exacerbate lingering doubts left by the vaccine’s highly politicized rollout in Russia, where President Vladimir Putin announced that the drug was ready for use in August, before clinical trials had finished.

Russia has repeatedly denounced foreign questioning of its vaccine as the fruit of anti-Russian conspiracies and prejudice, ignoring complaints that Putin, rushing last summer to declare a Russian victory in the race for a vaccine, violated standard procedure by declaring Sputnik V safe before trials had finished.

In postings from Moscow on his Facebook page, Matovic, the former Slovak prime minister, complained of a “dirty game” in Slovakia and accused his country’s politicians of “barking” like little dogs. He said that Slovakia, under the original deal with Russia, had agreed to buy 2 million Sputnik doses, and added that he would work to block what he called “insidious and systematic efforts” to derail the deal.