Every year we hear, read and see thousands of people dying as a result of dengue fever in many countries of the world such as Brazil, Cuba, Indonesia, Colombia, Mexico, Honduras, China, Malaysia, Vietnam, Myanmar, Nicaragua, Paraguay, Venezuela, Sri Lanka, Singapore, Philippines, Pakistan, India, Thailand, etc. This dengue virus has now become a permanent threat for the aforementioned and many other countries. In the past, different scientists have been successful in inventing different vaccines for controlling the spread of many diseases such as Hepatitis A and B, Influenza, Measles, Mumps, Polio, Rabies, Smallpox, Tetanus, Typhoid, Varicella (Chickenpox),etc. Lives of millions of people are secured annually throughout the world against the above referred diseases by simply injecting diseases-preventable vaccines right from the newly born baby to a child/person of a certain age. Why, then, our current scientists have failed so far in inventing the vaccine for the dengue fever as well? We can prevent the spread of dengue virus equally in all the affected countries if the people concerned are able to invent a vaccine for the same. ABDUL SAMAD SAMO, Karachi, September20.