Slovakia on Monday became the second European Union member state to administer the Russian-made Sputnik V COVID-19 vaccine.
The Russian jab has not been authorised for use across the 27-country bloc by the European Medicines Agency (EMA) but has already been rolled out in Hungary.
Slovakia approved Sputnik V for general use on May 26, with people allowed to pre-register to receive it from June 1.
It now has 200,000 doses of the vaccine available but so far just 5,000 people have registered to receive the two shots required for maximum efficiency.
Sputnik V is being administered to people aged 18 to 60 in the country and is available in eight vaccination centers.
More than 1.8 million of Slovakia's 5.4 million inhabitants have received at least one dose of the vaccines developed by Pfizer/BioNTech, AstraZeneca/Oxford University and Moderna, all three of which have been approved by the EMA. More than 950,000 people in total are fully vaccinated.
The country is also expected to roll out the Johnson & Johnson jab, which has now been approved by the European watchdog.
In March, a secret deal for Slovakia to purchase 2 million doses of Sputnik V, which was orchestrated by then-Prime Minister Igor Matovic, triggered a political crisis that resulted in the Slovak government’s collapse.
The following month, the maker of Sputnik V demanded the country return the doses it had already received after Slovakia’s State Institute for Drug Control claimed the vaccines the country had received were different to those sold elsewhere.
The institute also said it had not received enough information about Sputnik V to be able to properly assess its benefits and risks.
The official Twitter account of the Sputnik V vaccine then accused Slovakia’s drug regulator of an "act of sabotage", claiming it had "launched a disinformation campaign against Sputnik V and plans additional provocation".
Euronews has contacted the government for comment.