1 / 12The coronavirus has swept the world and is likely to have an adverse effect on the economies of many countries. Many patients might have got a cure however the search for the elusive vaccination which can eliminate the virus completely is still awaited.2 / 12While over 100 vaccines are currently under pre-clinical trials and a couple of those have entered human trial stage, leading health experts have raised alarming questions about what if the world never sees a COVID-10 vaccine, as in the case of HIV and even dengue where there is no vaccine even after years of research.3 / 12According to a CNN report, 'there is another, worst-case possibility: that no vaccine is ever developed'.4 / 12In this outcome, 'the public's hopes are repeatedly raised and then dashed, as various proposed solutions fall before the final hurdle', the report said on Sunday.5 / 12Nearly four decades and 32 million deaths later, the world is still waiting for an HIV vaccine.6 / 12An effective vaccine for dengue fever, which infects as many as 400,000 people a year according to the World Health Organisation (WHO), has eluded scientists for decades.7 / 12A vaccine to prevent dengue (Dengvaxia) is available in some countries for people ages 9-45 years old. But the WHO recommends that the vaccine only be given to persons with confirmed prior dengue virus infection.8 / 12According to the US Centers for Disease Control and Prevention (CDC), the vaccine manufacturer, Sanofi Pasteur, announced in 2017 that 'people who receive the vaccine and have not been previously infected with a dengue virus may be at risk of developing severe dengue if they get dengue after being vaccinated'.9 / 12According to Dr Anthony Fauci, Director of National Institute of Allergy and Infectious Diseases (NIAID), the vaccine could happen in 12-18 months.10 / 12The COVID-19 disease could be with us many years into the future and lockdown is not sustainable economically.11 / 12Currently, a vaccine candidate for COVID-19 was identified by researchers from the Oxford Vaccine Group and Oxford's Jenner Institute. 12 / 12The potential upcoming vaccine, ChAdOx1 nCoV-19, is based on an adenovirus vaccine vector and the SARS-CoV-2 spike protein.