A vaccine is a biological agent that provides immunity to disease.It usually takes 10 to 15 years to develop a vaccine against a new disease.
Recently, the world health organization estimated that it would take at least 18 months to develop and release a novel coronavirus vaccine.For many of us, faced with anxiety about an uncertain future, vaccines seem to be a shining beacon of hope.
However, compared with standard procedures and vaccine development in the past, that 18 months is a fast track.A normal vaccine formulation can take 10 to 15 years or more.This time, researchers were able to fully understand the disease and its pathogens, and to ensure that vaccines against the disease were safe.To understand this further, let’s look at the steps needed to create a vaccine for a new disease.
There are several steps to making a vaccine:
The basic research and exploration phase
The basic research
In war, opponents must know the enemy before they can meet them on the battlefield.Likewise, scientists must understand a disease and its pathogens before they can attack it.
The researchers studied the basic biology of the pathogen: its genome, proteins and enzymes, its shape, structure and size, its reproductive patterns, how it causes disease, and its immune response to disease, to reveal different strategies for dealing with it.
It is difficult to estimate how long basic research will take to arrive at an answer.Different diseases behave differently in the body;Some diseases are easier to solve than others.Basic research provides the basis for the first step in creating a vaccine formulation.
As scientists learned about the pathogen, they began to target its Achilles’ heel.They decided which vaccine strategy (for example, live, attenuated, or subunit) was best suited to provide the immunizing agent with the weapon against the disease.
The researchers identified different antigenic molecules that induced an immune response to the disease and selected the most appropriate initial formulation.
Scientists must understand the biology of the disease before they can make a vaccine.
Most of the work here is trial and error and experimentation.All this takes time and a degree of luck to come up with a formula that has a chance of working in humans.
This phase usually lasts two to four years.
Animal models and cell culture
The agent was tested on animals to check its safety and effectiveness before being transferred to humans.Animal models and cell cultures mimic human systems.Once in a live system, the vaccine may not work as expected, so animal models provide crucial information about how the human system responds to the vaccine.
Cell culture is a more ethical way to examine how vaccines work and provide insights into the cellular and molecular changes that vaccines can cause.
The preclinical phase may take 1-2 years.
During that time, a company may also take a breather, slowing down the analysis of formulation data and outlining any possible improvements or risks to the vaccine before moving on to the next step.
Clinical trials are where many vaccines are refused formal approval.Just because a vaccine formula works in an animal model does not guarantee it will work in humans.
To enter clinical trials, manufacturers, usually private pharmacology or biotechnology companies that specialize in vaccine development, must first obtain approval from the relevant government agencies.
In the United States, the food and drug administration (FDA) ignores all approvals for investigational new drug (IND) applications.There are similar programs all over the world.
Figure note: vaccines in clinical trials are now being tested on human volunteers
Clinical trials were conducted in three rounds
The three clinical trials were differentiated based on two characteristic sample sizes and whether to use a placebo.Sample size is important because larger samples mean more robust data and more reliable results.The use of placebos in vaccines can help determine whether the vaccine is significantly more effective than ordinary salt or sugar solutions, or better than past vaccines.
The first phase of the clinical trial consists of no more than 100 volunteers.During this phase, researchers closely monitor the safety of the vaccine.They check to see if the vaccine causes any harmful side effects, allergies or other adverse reactions.This is a critical step, and often an obstacle that many formulations fail to pass.The safety of the vaccine is crucial because it is technically a disease preparation made up of foreign bodies injected into the body.
Many formulations have had to be redone based on phase I trial data in order to improve safety.
If the vaccine passes the first stage, it will move on to a second stage, which will involve a larger number of volunteers, divided into groups.In these groups, the efficacy of existing vaccine formulations in humans was compared with a placebo (a simple saline, sugar solution).
The third and final stage is the “real” test of the vaccine.Here, with the largest number of volunteers, thousands, every parameter, safety and efficacy of the vaccine, is checked again in this larger data set.
These trials must be double-blind in nature, especially in the third phase.In the double-blind trial, neither the managers nor the patients knew whether they were taking a placebo or a trial vaccine.The double-blind method is designed to eliminate human bias as much as possible, so that the raw data speaks for itself.They are the gold standard in drug testing.
These phases often have subphases, where sample sizes may vary.In these clinical trials, information is provided on the time required for immunization after vaccination, the duration of immunity to the disease (only a few months or years), and so on.All of these phases together may take more than five years to complete.
After that stage, companies will now rush to license and patent the vaccine.These procedures can take months to review, negotiate and authorize.In addition, manufacturing and production must be streamlined.
This timeline is an estimate.In some cases, it can take more than 15 years to develop a vaccine.For example, in 1993 a vaccine against human papillomavirus entered a phase of transition from preclinical to clinical, and it took another nine years to move forward again.
Patent government agencies issue patents for new vaccines.
On the other hand, a flu vaccine can be made within six months.The flu virus mutates so quickly that new vaccines are needed every year to fight new strains of the virus.Every time a new strain is found, manufacturers move quickly to produce a new vaccine against it.This is possible because of basic research and data collected over decades, which gives researchers a reliable framework to work with.
Medical groups around the world are trying to develop a vaccine against diseases such as HIV and malaria, but have yet to find a successful formula.These diseases have been studied since the 20th century and have killed millions of people worldwide.
The scientific process can be simplified so that new drugs and vaccines can be created in a systematic way.However, science is also done by humans and our still developing technologies.Sometimes it takes years for a new technology to open the door to a vaccine that prevents disease more quickly.
Nine companies have entered clinical trials of the covid-19 vaccine.These vaccine preparations are likely to receive fast-track approval, which means that full information and documentation on these vaccines will be a top priority.Despite the fast track approach, it is critical that scientists thoroughly test and ensure the safety of all parameters.