In this present year, COVID-19 has affected more than 50 million people and was the cause of more than 1.4 million deaths worldwide, for that reason many pharmaceutical companies started a race against time to develop a vaccine. In Mexico, the disease has affected more than one million people and caused approximately 106,000 infected patients to die, although it is suspected that these numbers could be much higher. To contain the ravages of this epidemic, it is not only necessary to apply the prevention measures that we all know, but also the application of a safe and effective vaccine against COVID-19 as well as the development of medicines that can effectively treat those who are already infected.
How does SARS-CoV-2 attack the organism?
The coronavirus SARS-CoV-2, which causes COVID-19, enters the body through the respiratory tract. It adheres to the cells that cover it using its spikes, which give it the characteristic corona appearance and are formed by a substance known as “S” protein. These spikes stick to different body cells that have receptors for the angiotensin converting enzyme type 2 (ECA-2) on their surface. This enzyme’s main function is to regulate the body’s blood pressure. Once the viral spikes bind to the receptors, the microorganism transfers its genetic material to the human cell through ribonucleic acid (RNA). A small strand containing genetic information code. Once inside the cell, RNA uses certain components of it to replicate itself and form a protective layer for hundreds of new viruses that emerge from the initially infected cell and finally infect other cells while this one dies.
Phases in vaccine acceptance
Vaccines, like other drugs, must go through several stages in their production process before they are licensed for widespread use in humans, for that reason the pharmaceutical companies cannot make covid vaccines quickly.
The COVID-19 emergency has caused some drug approval mechanisms to be modified in order to speed up the process to have a vaccine available as soon as possible.
The first phase is the pre-clinical stage, in which the vaccine is administered to monkeys or other animals to verify whether an immune response is produced.
This is followed by phase 1, which consists of applying the vaccine to a small group of humans to test its safety and corroborate the dose needed to elicit an immune response.
During phase 2, the vaccine is tested in hundreds of people from different risk groups.
In Phase 3, the same phase in which the most advanced COVID-19 vaccines are currently being tested, thousands of people are given the vaccine, while a similar number of people are given a placebo.
That is, a substance that has no effect on the organism.
It is precisely at this stage that it is possible to test whether the vaccine is really effective in preventing infection.
After this, the vaccine undergoes an approval process by the regulatory bodies of each country.
The function of vaccines in the production against COVID-19.
Molecular, genetic and infection mechanisms of coronavirus must be taken into consideration by pharmaceutical companies to implement different types of vaccines and their mechanisms of action.
Four types of vaccines associated with COVID-19 stand out and each one is based on different mechanisms that once entering the organism have as objective to produce an immune response, generating defenses and attacking the virus.
Inactivated virus vaccines:
These vaccines are based on virus proteins that are inactivated by different processes to prevent them from causing infection when administered to the body.
Instead they generate an immune response, do not confer total protection and it is common that several doses are required to produce immunity.
The companies Sinovac, Bharat Biotech and Sinopharm are the main references in this type of mechanism.
Vaccines based on proteins:
The immune system is capable of recognizing and destroying viral proteins without the need to directly expose itself to the virus and its replication.
This process of immunity is related to Novavax and other non-big players, such as Kentucky Bioprocessing and Sanofi.
Genetic vaccines (against RNA):
Most of this type are both in their third phase of studies and in acceptance processes, the top exponents are:
- Pfizer with BioNTech
- Moderna
- CureVac
- Arcturus
- Walvax Biotech.
Its mechanism consists of the detection of viral RNA by the immune system, which can identify it before the generation of viral proteins.
Therefore, it is the optimal method to eradicate an infection from the organism and it has been proven to be safe and effective.
Vectored Vaccines:
These use other viruses which are unable to replicate, to release genes from SARS-CoV-2 into the body in the form of Deoxyribonucleic acid (DNA). This then enters human cells and produces proteins that are able attack the virus. This method is used by AstraZeneca, Johnson & Johnson, CanSino Biologics, and Gamaleya Research Institute.
Pfizer – BionTech y Moderna, quienes han emitido los datos estadísticos más consistentes.
Pfizer – BioNTech, Moderna and AstraZeneca: the greatest players in the fight against COVID-19
At the beginning of 2020, when the rapid spread of the disease emerged, various pharmaceutical companies decided to start creating a prevention method capable of combating COVID-19.
This is the case of the alliance between Pfizer, a company focused on drug creation, and BioNTech, a company specialized in developing immunotherapies.
At present, this alliance is bearing fruits far superior to that of other companies; on November 23rd it was announced that efficacy following application of their vaccine BNT162B2 in test subjects was over 95%.
These are impressive statistical figures as they speak to a promising cure developed in a short time period.
Two doses are required over three weeks’ time with immunity established after one month.
Moderna is another pharmaceutical company vying for pole position; as reported on November 30th their messenger RNA (mRNA)-1273 vaccine has been effective at 94.1% following its administration to more than 30 thousand volunteers.
Another important player is AstraZeneca whose vaccine has yielded inconsistent efficacy results; two doses with a gap of one month apart are required but have yielded bewildering results with 3000 study participants receiving an incorrectly administered dose which proved effective at 90%, whereas 9 thousand recipients of correct doses had an efficacy rate of only 62% – data which impacts both possible use for the vaccine and image for the company.
Phase 3 studies have concluded for major two players Pfizer – BioNTech and Moderna who have released most consistent statistical data.
What does this mean?
It was successfully applied in specific people who have not been infected by coronavirus.
In addition to those who have already had contact with infected people, obtaining excellent results and confirming that it has not generated any severe side effects in the short term.
In the words of the representatives of the aforementioned companies, the standards required by the United States Food and Drug Administration (FDA) to be validated as emergency treatments in the world.
Expected effectiveness after distribution
Regardless of which vaccine we are talking about, effectiveness is an important point when dealing with any disease, especially if it represents the most important one nowadays.
Accordingly, the use of these vaccines depends to a great extent on their safety and efficacy.
Therefore, it is important to collect the results obtained after implementing the necessary doses in people, encompassing ages, as well as healthy subjects and people with specific diseases (e.g. infected by hepatitis B and C virus).
Immunity is another relevant point; it is currently unknown for how many weeks, months or years such protection will be maintained, whether two single doses will be necessary throughout life or whether periodic boosters will be required.
It should be emphasized that they have not been administered in a large number of people in comparison with the world population; the body’s response could vary with respect to various risk factors already present in different patients.
It is possible to have a general idea of the factors that are involved as well as their long-term side effects, depending on:
- age
- race
- different comorbidities already present in the patient
- pregnancy
- smoking
- alcoholism.
Likewise, the efficiency of the vaccines in production could be increased if some of the drugs used to control COVID-19 infections were also implemented.
These have had a great performance in the medical field.
COVID-19, when and for whom will the vaccines be available?
It is expected that in the last month of the year the FDA will give the green light for Pfizer, Moderna and AstraZeneca to export their vaccines to the main countries where they were requested, in this case:
- Canada
- Japan
- United Kingdom
- United States.
These vaccines will have a limited use during their first month and will be aimed mainly at health care workers and older adults with age-related conditions.
It is of great interest to note that they will not be available to the general public at first.
But this should not be a cause for alarm; priority will be given to different sectors of the population according to the specific needs of each country.
In the meantime, the protection methods known so far should be maintained.
Such as hand washing, use of masks and disinfection of objects around us.
Pfizer’s estimated price per vaccine is 20 dollars and it is known that 2 applications are required.
On the other hand, Moderna plans to charge approximately 35 dollars per dose.
Surprisingly, AstraZeneca plans to sell them for 3 dollars to developing countries once they finish their trials.
Other companies with different COVID-19 vaccines in development
According to the World Health Organization (WHO) database, as of November 27, 2020, 48 different types of vaccines are registered as candidates for future prevention against COVID-19 and 164 are still in pre-clinical evaluations.
For Grupo PACS and Teleradiology it is of great importance to keep the population informed about the advances related to the development of COVID-19 vaccines.
In addition to other treatments for this disease so we will keep track of these events worldwide.
Especially in our country as a way to collaborate in the fight against the pandemic caused by the coronavirus.
