It seemed to begin with a single tweet on Twitter. On 24 January an organisation called Principia-Scientific International reported that the small island (sic) of Gibraltar "has seen no fewer than 53 locals dead after having the Covid-19 vaccination in the past 10 days". A media bias fact-check site has categorised Principia-Scientific as being very low in terms of factual reporting and describes it as dealing in conspiracy and pseudoscience.
On this occasion, PSI claimed to have received a "heartfelt plea" from a Gibraltarian, asking for help spreading another article which claimed that the Gibraltar government was committing an act of mass genocide.
The report was tweeted by the CEO of Principia-Scientific, and Gibraltar's chief minister, Fabian Picardo, was quick to respond, saying the claim that people had died because of the vaccine was an "unadulterated, utter lie" and nobody should believe a word of such nonsense. Public Health director Sohail Bhatti also tweeted in response, saying it was a deliberate fear-mongering exercise designed to harm.
However, as the expression goes, the disinformation went viral. The claim that Gibraltar's death rate had shot up because people had been vaccinated appeared in numerous other publications on social media, in different languages and in different countries, with none of them making any attempt to support their claims. Many people in Gibraltar, incensed, pointed out that the reports weren't true, but still they continued to appear.
On Wednesday, matters had reached such a point that the government of Gibraltar issued an official statement saying there is no evidence that any of the 11,073 people who have been vaccinated had died as a result of any reaction to the vaccine, and that "statements to the contrary on social media are entirely untrue and originate from discredited individuals and organisations".