As the world races to develop a Covid-19 vaccine, doctors are increasingly turning their attention to alternative treatments. The latest research suggests that the flu jab may be able to prime the immune system to attack invading coronavirus cells, potentially reducing the risk of death by more than a third. The flu jab is among a slew of medicines that have been repurposed for coronavirus: Two studies - in Italy and in Brazil - found that those who had received the jab were less likely to die from coronavirus. In the Milan University study, researchers examined hospital admissions and deaths in areas with high flu vaccine uptake and areas where few people got the jab. They found the coronavirus death toll was about 150 per 100,000 of the population in areas where fewer than 30 per cent were immunised against the flu. The Brazil study tracked more than 90,000 Covid patients and found mortality rates were up to 35 per cent lower among those who received a flu jab, compared with those who didn’t. Researchers believe the tuberculosis vaccine could help boost immunity to Covid-19. Thousands of people around the world are being recruited for trials to investigate whether the Bacillus Calmette-Guerin vaccine could help fight the disease until a tailored jab is found. The TB vaccine has previously been shown to reduce susceptibility to a range of diseases caused by viruses. Donald Trump was provided a dose of drug maker Regeneron’s experimental antibody treatment. Still in clinical trials, the new antiviral antibody cocktail works by binding to a protein on the surface of the virus. It is meant to stop the virus from attaching to cells and replicating, while still allowing the immune system to fight back. The antiviral drug was originally developed to treat hepatitis C but was recently used in the recent Ebola outbreak. It works by attacking the virus once it’s already inside the body. Considered an effective treatment, the drug is a “broad-spectrum” antiviral and it works against a range of viruses. The steroid reduces inflammation by mimicking anti-inflammatory hormones produced by the body. Coronavirus infection triggers inflammation as the body tries to fight it off, but sometimes the immune system goes into overdrive and it's this reaction that can prove fatal. The malaria medication was touted by Mr Trump as a Covid-19 treatment but health authorities were quick to dismiss the medication as ineffective. US Food and Drug Administration cautioned against using the drug to treat coronavirus patients, following reports of "serious heart rhythm problems" and other health issues.