More than 100 million Covid-19 vaccines have been given around the world and already some countries say they are experiencing a decline in hospital admissions, severe cases and deaths as the world races to end the pandemic. Israel leads the race by far, with 37 per cent of its population having received at least one dose, while more than a fifth have already got their second. While picture emerging in Israel was a positive sign, there are still deep concerns. The richest nations account for more than two thirds of vaccines administered. None of the world's 29 poorest countries has formally started mass vaccination drives. That’s more than a third of humanity (35 per cent) living in countries where vaccination has yet to begin. After Israel, the countries that have given the most doses are in the Gulf, North America and Europe. The UAE comes after Israel in number of doses administered per 100 people, followed by the UK. The US is currently fourth, although it has ambitious targets for vaccination. Eran Segal of the Weizmann Institute of Science in Israel on Tuesday highlighted the impact the vaccination campaign already appears to be having. In the age group of 60 and above,, who have been prioritised in the country's vaccination programme, there has been a 35 per cent drop in cases, a 30 per cent drop in hospital admissions and a 20 per cent drop among critically ill. These, he pointed out, were larger shifts than in previous lockdowns and were a good sign that things could start to improve rapidly as Israel progresses with the programme to get everyone a vaccine. The World Health Organisation lamented that "rich countries are rolling out vaccines while least-developed countries watch and wait". Some rich countries, however, have yet to start vaccinating, including Japan, South Korea and Australia, which have managed to contain the pandemic with strict border controls and quarantines. The first deliveries of the WHO's Covax scheme to share vaccine doses more fairly are due begin this month. So far, only Guinea has benefited, with only a few dozen given in a pilot trial. There are currently seven vaccines in circulation around the world, all designed to be given in two doses. The vaccines developed by Pfizer-BioNTech and Moderna are dominant in North America, Europe, Israel and the Gulf. Britain's AstraZeneca-Oxford is used in much of the UK and India, Myanmar, Sri Lanka and Morocco, and is soon to be introduced in Europe. India also uses a home-grown vaccine produced by Bharat Biotech. Russia's Sputnik V vaccine has been introduced in Russia, Argentina, Algeria, Belarus and Serbia. China's Sinopharm shots are being administered in China, the UAE, Bahrain, Serbia, the Seychelles and Jordan, while Indonesia and Turkey are using China's Sinovac vaccine. China's Sinovac vaccine and Russia's Sputnik V doses have yet to be fully approved by either Beijing or Moscow's health authorities.