Adapted in English by Valérie Harnois
As part of a series of information capsules SCOOP! on COVID-19, today we address vaccines. Creating a vaccine is a complex process and there can be more than a year between its creation and its distribution to the public. Where are researchers in their quest to stop this pandemic? SCOOP! explains it in this video.
More Information on Vaccines
Inoculation is the process of introducing a pathogen, often in the form of a vaccine, hat will cause the body to create an immunity against the disease.
The Roles of Vaccines in Inoculation.
Vaccines protect people by preventing them from developing certain dangerous diseases. During inoculation, the weakened bacteria or virus is introduced in the body. The weakened infectious agent is harmless to our health since it cannot cause the disease. This is when the immune system gets to work and starts fabricating antibodies to fight the new bacteria or virus. The body prepares and trains to fight the enemy and if the real disease comes along, the person is already protected and will most likely not get sick.
The antibodies that are developed due to the vaccine will be efficient only against the particular strain of bacteria or virus that was injected into the body. For example, since there are over 60 types of flu viruses, and the flu vaccine only targets three strains, the body will most likely be immunized against the strains injected but not the others. Usually, the vaccines target the virus or bacteria that are most present during the year and therefore reach their protection objective.
Creating a Vaccine
The fabrication process of vaccines transforms bacteria and viruses so that they lose their pathogen charge, yet retain their characteristics. Once injected with the vaccine, the body starts producing specific antibodies without developing the disease. To start the fabrication of a vaccine, researchers grow massive cell cultures of the bacteria or virus. Then, the cells collected from the culture are heated and treated with chemical products to make them harmless.
There are four processes in the conception of vaccines.
Live-Attenuated Vaccines. They use a live pathogen that lost its power to infect people because of the chemical treatments it went through. Live-attenuated vaccines are used in the case of measles, mumps, rubella (MMR combined vaccine), rotavirus, smallpox, chickenpox and yellow fever.
Inactivated Vaccines. They use a dead version of the pathogen. Because it is dead, it does not produce as many antibodies as the live-attenuated vaccines. This is why many booster shots are often required. Inactivated vaccines include Hepatitis A, flu, polio and rabies.
Subunit/conjugated Vaccines. These vaccines use only a piece of the virus or bacteria, most often only a protein that is unique to the disease. Once in contact with the protein, the body recognizes it and creates an immune response to it. Those vaccines include hepatitis B, influenza, Hib, pertussis (part of DTaP combined immunization), pneumococcal, meningococcal and HPV.
Toxoid Vaccines. These vaccines do not use the bacteria or virus. Instead, they use the toxin created from them and render it harmless. It is the same process as inactivated vaccines but used with the toxin instead of the germ. Why do they use the toxin? Because those bacteria or viruses are not the problem. What gets us sick is the toxins they release. Those vaccines include diphtheria and tetanus (part of DTaP combined immunization).
What About COVID-19
At this point, the scientific community works day and night to create a vaccine to protect the population from COVID-19. No date has been set for its release. Some clinical trials are ongoing. In Seattle, 45 volunteers will test the vaccine for a period of 6 weeks. They received their vaccine mRNA-1273 on March 17, 2020. If all goes well and the tests are conclusive, there could be another 18 months before this vaccine is available to the public.
No remedies have ever been found, in the history of humanity, against coronaviruses (COVID-19 is a type of coronavirus). Nevertheless, the current research is promising and could stop the pandemic in a few months. The first tests were set up in record time. Pharmaceutical groups and research laboratories across the world have entered a race to develop treatments and vaccines against this new coronavirus. This competition between laboratories could be beneficial and contribute to a more rapid commercialization of a remedy.
In the absence of an available vaccine for the next few weeks and months, quarantine is the best way to control the virus, as explained in this other capsule.
Statistics on COVID-19
According to the World Health Organisation (WHO), 80% of people contaminated experience mild symptoms, 14% are severely ill 5% are critically ill. People who are critically ill with COVID-19 experience severe respiratory problems where the lungs fill with fluids and oxygen cannot reach the organs. Patients with mild affliction usually recover within one or two weeks whereas more severe cases take up to six weeks to recover. According to recent analysis, it can be fatal to less than 1% of people afflicted.
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