Dr Anthony Fauci, the top US infectious disease expert, has revealed that scientists in the US are preparing to upgrade Covid-19 vaccines in order to address the variants of the virus which are circulating in the UK and South Africa. As Dr Fauci made this announcement, producer Moderna stated that, though its Covid-19 vaccine works against the variants, it is also developing a new injection to be used as a 'booster shot'. ‘An insurance policy’ Speaking to the New York Times, Moderna’s chief medical officer, Dr Tal Zaks, said: “We’re doing it today to be ahead of the curve should we need to. I think of it as an insurance policy. “I don’t know if we need it, and I hope we don’t.” The company said laboratory tests found that vaccination with its vaccine produced neutralising antibodies against all key emerging variants - including the South African mutation. The study showed no significant impact on antibodies against the UK variant, relative to prior variants. While there was a six fold reduction in neutralising antibodies produced against the South African variant, the levels remain above those that are expected to be protective, Moderna said. Moderna collaborated on the study, alongside the Vaccine Research Centre at the National Institute of Allergy and Infectious Disease, which is part of the National Institutes of Health. The results have not yet been published, or peer reviewed, but have been submitted to bioRxiv. ‘It is imperative to be proactive’ Stephane Bancel, chief executive officer of Moderna, said: “As we seek to defeat the Covid-19 virus, which has created a worldwide pandemic, we believe it is imperative to be proactive as the virus evolves. “We are encouraged by the new data, which reinforces our confidence that the Moderna Covid-19 vaccine should be protective against these newly-detected variants.” Bancel added: “Out of an abundance of caution and leveraging the flexibility of our mRNA platform, we are advancing an emerging variant booster candidate against the variant first identified in the Republic of South Africa into the clinic to determine if it will be more effective to boost titers [antibodies] against this and potentially future variants.” ‘The vaccines we have now do work’ Dr Fauci said he was especially concerned about the new South African variant of Covid-19, which he described as “different and more ominous than the one in the UK”. He commented: “The data did not come out officially, but taking a look at the preliminary data that the UK scientists have analysed, I’m pretty convinced that there is a degree of increase in seriousness of the actual infection, which we really have to keep an eye on.” The doctor added that there is also a “very slight, modest diminution” of effectiveness of the Covid-19 vaccines against these variants - but also, that “there’s enough cushion with the vaccines that we have that we still consider them to be effective against both the UK strain and the South Africa strain”. Fauci said: “We really need to make sure that we begin, and we already have, to prepare if it’s necessary to upgrade the vaccines. “We’re already taking steps in that direction despite the fact that the vaccines we have now do work.”