Questions and Answers about Vaccine

"Everyone is a writer" program aims to promote the sharing of knowledge and learning together. We encourage scientists, researchers, and students to answer the questions with their expertise and help  others learn from the answers. There are some questions and answers about the vaccine from this campaign.

Q: Vaccine can prevent the organisms from the virus infection. How does it work? How to develop it? Are there any bottlenecks to develop vaccines? Please share your knowledge and perspectives on those vaccine related questions.

A: Kamini V: WEAKEN THE VIRUS - Using this strategy, viruses are weakened so they reproduce very poorly once inside the body

Examples: The vaccines for measles, mumps, German measles (rubella), rotavirus, oral polio, chickenpox (varicella), and influenza (intranasal version) vaccines

Advantage:  One or two doses provide immunity that is usually life-long

Limitation:  These vaccines usually can not be given to people with weakened immune systems (like people with cancer or AIDS). Learn More

Melissa fang: Before we talk about how vaccines work, we need to understand what immunity is. Our immune system can recognize foreign invaders, also called an antigen, and produces antibodies against it. The first time the body encounters an antigen, it can take several days for your body to produce antibodies, and you will get sick. But the antibodies will remain in your bloodstream, and if the same antigen tries to infect you again, the antibodies will prevent you from getting sick. Learn More

Ayu Harnis: Antiviral vaccines work by inducing specific antibodies for the surface glycoprotein of a hidden virus or capsid protein from an uncovered virus. The antibody response works best when it neutralizes and inhibits infection. Neutralization can occur in three main mechanisms. First, virus aggregation or immobilization reduces the infectious inoculum by preventing the virus from reaching the target cell. The second mechanism involves antibodies that directly block the attachment of the virus to the target cell by covering the receptor-binding domain. Third, neutralization can occur post-attachment by preventing entry or release through inhibition of fusion[1]. Learn More

Dickens Hall: When a pathogen invades the body, the immune system can respond by producing immune cells (macrophages, B-lymphocytes and T-lymphocytes) to fight back. The battle between immune cells and the pathogen during infection can last several days. After that, the body keeps some memory cells that can react immediately to the same pathogen. When similar pathogens are identified in the body, antibodies can be sent by B-lymphocytes to destroy them. What a vaccine does is to imitate the infection process. A high-quality vaccine is supposed to cause the immune system to develop immune cells and antibodies without causing any concerned diseases, though some minor symptoms like fever may occur in some cases. Learn More

Neelofar Tamboli: There are three main types of vaccines; live-attenuated, inactivated, and subunit vaccines. Live-attenuated vaccines work by weakening the original pathogen. Inactivated vaccines are killed pathogens. Subunit vaccines are one part of the original pathogen, which we call antigen. Antigens trigger the immune response to the pathogen. To develop vaccines, researchers have to isolate and purify the viral material in order to ensure that the material is free of impurities. Then, depending on which vaccine type they are trying to make, they will either kill or weaken the pathogen by destroying some viral DNA in order to prevent viral replication. One bottleneck in the development of vaccines is the rate at which the virus mutates. Since the virus mutates fast, it is hard to keep up with a standard vaccine. Another problem is the increase in vaccine prices. Although there are next-generation vaccine development research going on now, the price of vaccines has been plummeting. Learn More