 For more videos on people's struggles, please subscribe to our YouTube channel. The beginning of the new year has brought with it some hope, as different countries have started administering vaccinations against COVID-19. This has been the fastest development of a vaccine ever within the number of research collaborations to make this feat possible. A number of these vaccines have also gotten approval by regulatory agencies. The main ones include vaccines developed by Oxford University in AstraZeneca, Pfizer and BioNTech, Moderna in collaboration with the National Institute of Allergent Infectious Diseases in the US, the Sputnik 5 vaccine developed by Rasheer's Gamalaya Institute, the vaccine developed by Sinofarm Group, a Chinese government-owned pharmaceutical company. Dozens of nations have started administering shots of these vaccines to their populations starting with the elderly and healthcare workers. The United Kingdom was the first to start the rollout of the Pfizer-BioNTech vaccine on 8 December. It also became the first to start inoculating people with the Oxford-AstraZeneca vaccine on 4 January. The US has so far administered over 4.6 million shots using the Pfizer and the Moderna vaccines. The Pfizer vaccine is also being used in Canada, Germany, Spain, Mexico, among other countries. The Sputnik 5 vaccine has been approved in Argentina, Bolivia, Serbia, Venezuela, Belarus, among other places. Russia has been administering this vaccine since September last year. Meanwhile, thousands of Chinese citizens, including frontline health workers, teachers and public transport workers, have already received a Sinofarm vaccine under an emergency use authorization. This vaccine has also received emergency use authorization in the UAE and Bahrain. So why are there so many vaccines and how are they different from each other? Given how dangerous the novel coronavirus has turned out to be, governments, usage organizations and pharmaceuticals across the world have been trying to develop a vaccine that can work against it. The general sense behind this is that the more vaccines we have to deploy, the better. All these vaccines have displayed varying rates of effectiveness, but all of them are much above the 50% rate mandated by the FTA for emergency use for vaccines. These vaccines also employ different methodologies for building immunity against the virus. For instance, both the Pfizer-BioNTech and the Moderna vaccines rely on genetic instructions known as messenger RNA or mRNA. This prompt cells to make a protein that can train the immune system to recognize SARS-CoV-2 virus. This is the first time mRNA vaccines have been approved for any disease. Whereas the AstraZeneca-Oxford vaccine works using a virus that causes the common cold in chimpanzees. This virus is modified so it cannot spread and cause disease in the body. It is then loaded up with a gene for the coronavirus spike protein. When this vaccine is injected in the human body, it starts to produce the spike protein. The immune system detects this protein and produces active bodies. These active bodies would also then be effective against the real coronavirus should the person get infected. Russia's Sputnik 5 vaccine also uses this adenovirus vector method. This is the more conventional approach of producing vaccines. Other vaccines are also taking such conventional approaches. The Sinopharm vaccine contains a chemically inactivated version of the entire virus. The vaccine developed in India-Babharat biotech called Covaxin also works in a similar manner. At the moment, the Pfizer vaccine is being used in the most countries. However, it requires to be stored in ultra-freezing temperatures, making it deliberately expensive and difficult in remote areas. At $20 to $25, the Moderna and Pfizer vaccines are also priced much higher than the Oxford AstraZeneca vaccine, which costs $3 to $4 a shot. The Oxford vaccine can also be stored in normal refrigerators for six months, making it the cheaper and more convenient option. The vaccines approved until now require the administration of two shots within a gap of a few weeks. Several countries are now debating whether to give just one shot for now in order to provide some immunity to a greater number of people. The UK for instance has approved delaying the second shot of the vaccine to 12 weeks after the first one. The WHO has called this a risky move, saying there is no scientific evidence for a delay of more than six weeks in administering the second dose of the Pfizer-BioNTech vaccine. In India as well health, authorities are in a rush. The indigenously developed vaccine called Covaxin has been approved without data available on its effectiveness. Scientists are worried that this disregard of scientific and regulatory processes will dilute the overall potency of the vaccinations and also feed into anti-vaccine anxieties. Vaccines also still remain inaccessible from many countries. Apart from a few rich nations and countries with indigenous capabilities, most others may not be able to significantly vaccinate their populations until the next couple of years. So while there is some hope that we may start to recover and protect ourselves from this virus, many challenges remain for this immunity to reach all people.