For years now, scientists have tried to develop a safe and effective dengue vaccine. The challenge however, is that there are four different types of dengue viruses, and a common vaccine must protect against all of them. Some vaccines developed in other countries have shown mixed results, but are not widely used Post navigation Delhi’s Lajpat Nagar double murder: Boy walked into scene of mother’s murder, tried to hide in bathroom; killer nursed grudge over scolding You have to say no a few times to get what you want: Sourabh Raaj Jain
