Vaccine – A hope and Science to understand.
written by :Dr. Ghias Ahmed( Bachelor of Pharmacy /Degree from Karachi University/General Manager Sales Marketing at Ray Pharma.)
When a disease is new, there is no vaccine until one is developed. It can take a number of years for a new vaccine to be developed. Researchers hope to achieve the same amount of work in only a few months in case of covid-19 Vaccines.The Corona virus spreads easily and the majority of the world’s population is still vulnerable to it.A vaccine would provide some protection by training people’s immune systems to fight the virus so they should not become sick.This would allow lock downs to be lifted more safely, and social distancing to be relaxed. If a vaccine is developed, then there will be a limited supply, at least initially, so it will be important to priorities. Healthcare workers who come into contact with Covid-19 patients would be on top of the list.The disease is most dangerous in older people so they would be on a priority if the vaccine was effective in this age group.However, it might be better to vaccinate those who live with or care for the elderly instead.Here I tried to help you out to better understanding of a Vaccine its definition, history and itsdevelopmental processes and protocols.
The ABCs of Vaccines
By definition a vaccine is “a product that produces immunity from a disease and can be administered through needle injections, by mouth or by aerosol.”The key ingredient in an effective vaccine is an inactive or weakened version of the bacterial or viral infection it has been created to prevent. When we get sick, we produce antibodies, or proteins that help our bodies fight illness.Vaccines weaponized our immune systems by imitating the virus or infection in question,which in turn prompts our bodies to create the same antibodies it would need to fight a full blown version of that illness. When or if we encounter that bacteria or virus, our bodies are prepared to counter it.
A brief history of Vaccination
The practice of immunization dates back hundreds of years. Buddhist monks drank snake venom to confer immunity to snake bite and variolation (smearing of a skin tear with cowpox to confer immunity to smallpox) was practiced in 17th century China. Edward Jenner is considered the founder of vaccinology in the West in 1796, after he inoculated a 13 year-old-boy with vaccinia virus (cowpox), and demonstrated immunity to smallpox. In 1798, the first smallpox vaccine was developed. Over the 18th and 19th
centuries, systematic implementation of mass smallpox immunisation culminated in its
global eradication in 1979.Louis Pasteur’s experiments spearheaded the development of live attenuated cholera vaccine and inactivated anthrax vaccine in humans (1897 and 1904, respectively).
Plague vaccine was also invented in the late 19th Century. Between 1890 and 1950,bacterial vaccine development proliferated, including the Bacillis-Calmette-Guerin (BCG) vaccination, which is still in use today.In 1923, Alexander Glenny perfected a method to inactivate tetanus toxin with formaldehyde. The same method was used to develop a vaccine against diphtheria in 1926. Pertussis vaccine development took considerably longer, with a whole cell vaccine first licensed for use in the US in 1948.Viral tissue culture methods developed from 1950-1985, and led to the advent of the Salk (inactivated) polio vaccine and the Sabin (live attenuated oral) polio vaccine. Mass polio immunisation has now eradicated the disease from many regions around the world.Attenuated strains of measles, mumps and rubella were developed for inclusion in vaccines. Measles is currently the next possible target for elimination via vaccination.
The past two decades have seen the application of molecular genetics and its increased insights into immunology, microbiology and genomics applied to vaccinology. Current successes include the development of recombinant hepatitis B vaccines, the less reactogenic acellular pertussis vaccine, and new techniques for seasonal influenza vaccine manufacture. The Path to Prevention / Development.
According to the CDC, there are six stages of vaccine development: exploratory, preclinical, clinical development, regulatory review and approval, manufacturing and quality control.
Exploratory: This research-intensive phase of the vaccine development process is designed to identify
“natural or synthetic antigens that might help prevent or treat a disease.” Antigens might
include weakened strains of a particular virus.
Pre-clinical:
During this phase, researchers — usually in private industry — use tissue-culture or cell culture systems and animal testing to determine whether the candidate vaccine will produce immunity. Many candidate vaccines don’t move on to the next stage of development because they fail to produce that immunity or prove harmful to test subjects.
Clinical development:
At this point, a sponsor, usually a private company, submits an application for an Investigational
New Drug (IND) to the U.S. Food and Drug Administration (FDA). This summarizes findings to
date and describes how the drug will be tested and created. An institution that will host the
clinical trial holds a review board for approval of the application. The FDA has 30 days to
approve the application. Once the proposal has been approved, the vaccine must pass three
trial stages of human testing:Phase I administers the candidate vaccine to a small group (less than 100 people) with the goal of determining whether the candidate vaccine is safe and to learn more about the responses it provokes among test subjects.Phase II, which includes hundreds of human test subjects, aims to deliver more information about safety, immunogenicity, immunization schedule and dose size.
Phase III, which can include thousands or tens of thousands of test subjects, continues to
measure the safety (rare side effects sometimes don’t appear in smaller groups) and
effectiveness of the candidate vaccine.Regulatory review and approval: If a vaccine passes through all three phases of clinical development, the vaccine developer submits a Biologic s License Application (BLA) to the FDA.Manufacturing: Major drug manufacturers provide the infrastructure, personnel and equipment
necessary to create mass quantities of vaccines. They also reap the profits of successful or
widely distributed drugs.Quality control: The approval and distribution is far from the end of the line. Stakeholders must adhere to procedures that allow them to track whether a vaccine is performing as anticipated.Multiple systems — including Phase IV trials (optional studies that can be conducted following
the release of a vaccine), the Vaccine Adverse Event Reporting System (VAERS) and the
Vaccine Safety Data link — are designed to monitor the performance, safety and effectiveness
of an approved vaccine.These processes, however, can’t happen without the skills and input of numerous stakeholders,from lab researchers to policymakers to medical professionals.
What sort of progress is being made up till now for Covid-19 Vaccine?Research is happening at breakneck speed. About 80 groups around the world are researching vaccines and some are now entering clinical trials.
▪ The first human trial for a vaccine was announced last month by scientists in Seattle.Unusually, they are skipping any animal research to test its safety or effectiveness
▪ In Oxford, the first human trial in Europe has started with more than 800 recruits – half will receive the Covid-19 vaccine and the rest a control vaccine which protects against meningitis but not corona virus
▪ Pharmaceutical giants Sanofi and GSK have teamed up to develop a vaccine
▪ Australian scientists have begun injecting ferrets with two potential vaccines. It is the first Comprehensive-clinical trial involving animals, and the researchers hope to test humans by the end of April
However, no-one know how effective any of these vaccines will be
