But what's the real story behind vaccine safety and effectiveness? By understanding the science and rigorous testing that goes into vaccine development, you can make informed choices for yourself and your loved ones. We spoke to our expert Dr Agam Vora, Medical Director, Vora Clinic, Mumbai, who explained why the science behind vaccines matters and how it can help dispel common misconceptions. According to a 2021 study, in 2018, the global population of children under five was estimated to be around 679 million. Of these, approximately 5.3 million children died from various causes, including an estimated 700,000 deaths from vaccine-preventable . Notably, 99% of these children lived in low- and middle-income countries. Yet, vaccination has been marred with controversies for many decades. Numerous myths and misconceptions prevail that make people avoid vaccination. "Vaccination hesitancy has almost become a public health threat that hinders the optimum use of this great scientific discovery. But the pertinent question is when you see questions being raised about the efficacy and safety of vaccination, whom should you believe? The answer is science," highlighted Dr Vora.   The Science Behind Vaccine Efficacy Rigorous research is conducted to test the efficacy and safety of every vaccination before it is released for public use. It is important to know all stages of vaccination development to understand the science behind its efficacy. Just like all other drugs, only when researchers are sure about their efficacy on animals are vaccinations tested on humans in clinical trials. Phase 1 Clinical Trials: Testing on a Small Group "During phase 1 clinical trials, a small group of people (20-100) receive the vaccination. The main purpose of this phase is to recognise the side effects of vaccination in humans and measure the immune response. Many vaccinations are withdrawn at this stage if the results are not favourable," said Dr Vora. Phase 2 Clinical Trials: Evaluation with a Broader Population Only a few move to the phase 2 trials in which the vaccination is tested on hundreds of people of different ages, genders, and health characteristics to know the side effects, risks, and immune response. Phase 3 Clinical Trials: Testing on Thousands of People After successfully demonstrating its efficacy in the phase 2 trials, the vaccination has to undergo phase 3 trials in which it is tested on thousands of people of different nationalities and living conditions to confirm its immune response and safety.   Transparency and Long-Term Monitoring All vaccinations approved for use must undergo all phases of testing. This process is transparent, and the research is published in the public domain at every stage. Even after the vaccination is approved for use, researchers continue to study its efficacy and safety for the long term. "In fact, real-world monitoring may reveal longer-term data than clinical trial conditions in real-world settings. For example, the shingles vaccination was approved for use only after its successful phase 3 clinical trials and the researchers continued to monitor the people who had received test doses of the vaccination. Now, it has come to light that the protection against shingles offered by vaccination continues for 11 years, a longer period than earlier estimated," said Dr Vora. Bottomline Dr Vora concluded, "It is easy to believe in vaccination myths and raise questions about its safety and efficacy. But this means we devalue the lifelong efforts of scientists who strive to develop vaccinations against dreadful diseases. Of course, while every person cannot develop the expertise to read and understand the clinical data, doctors shoulder the responsibility to stay abreast of all the scientific data and can answer your questions about the safety and efficacy of vaccinations. Don't believe in rumours, and please take the time to talk to your doctor about vaccination so that you can make informed decisions to protect yourself and your family."