HERD IMMUNITY

 

The death toll from COVID-19 reached millions, in a slow but steady escalation the disease has gained ground.

       Today the great hope has already arrived, vaccines are being implemented but it is still months away to get the vaccination of most people on the planet. There are currently two options for decreasing the effects on the population of this disease. One of them is to develop an efficient vaccine to inoculate it in the population as soon as possible. The other is to expect a large number of global people to become infected by the SARS-CoV-2 virus, and therefore, the more people become infected, the more people will have acquired, naturally immunity against this virus. then the number of immune people will be as high as it is so that the virus cannot find people without immunity.

      This is known as the herd effect.  It is believed that with between 60 and 70% of people who will get sick with the virus, it reduces the chance that the virus may find a person ineligible for attack, causing the danger of COVID 19 to decrease. But because the human population had never been exposed to SARS-CoV-2, the consequences of repeated epidemics would have a high level of mortality, serious economic shocks and great adjustments in our way of life. Therefore, the best option would be the vaccine.

      This concept was developed about a hundred years ago, but it was in the 1950s that vaccination campaigns began, that they became notorious. During mass vaccinations, it was expected that 70% of vaccinated children could prevent the remaining 20% from contracting the disease by reducing the number of infections.

      In the past it took decades to develop and produce a vaccine, so the goal of producing a reliable vaccine in less than a year will be unprecedented. An efficient vaccine is expected to be achieved by the end of 2020 or early 2021.

      However, new manufacturing platforms, structure-based antigen design, computational biology, protein engineering, and gene synthesis have provided the tools to now manufacture vaccines quickly and accurately.

 

   Antiviral vaccines can be classified into two broad categories:

      The first are vaccines based on the delivery of gene sequences that encode virus proteins within the patient. DNA or RNA that is introduced into the patient's body, reaches the cells and in them manufactures the proteins of the virus, which the immune system then takes as part of the dangerous virus, and begins to create molecules that can bind to the virus when it tries to invade the body. These include attenuated virus vaccines (with different techniques kill infectious viruses and then the remains are taken to redo the virus cover, but include within it only the RNA that manufactures proteins to be used for the immune system), vectors of recombinant vaccines or nucleic acid vaccines (RNA or DNA).

      Protein-based vaccines include whole inactivated viruses (the virus is killed), proteins are injected or part of them, against which the body can create immunity, or viral proteins assembled into large groups that in the body separate, all of which are manufactured in laboratories to prevent them from organizing and creating a live virus by being inoculated and ending up causing the disease.

      Nucleic acid vaccines are best suited for manufacturing because they can be more easily adapted to manufacturing technologies where the supply chains and the following processes are the same for each product. Accuracy is achieved by knowing the atomic structure of the virus protein.

      The coronaviruses, when they were first discovered, the photos taken under the electron microscope, showed a profile showing many "Thorns" exceling from the central sphere, that's what characterized them. Scientists call these "thorns" spikes, and help the virus enter the cell it intends to attack. These spikes are the main proteins used to develop immunity against that virus. When they inject a vaccine it's just these proteins or the genetic information for the cells to produce. The antibodies that the body produces to inactivate the virus are made to bind to the spikes and thus trap the virus.