COVID-19: Everything You Need to Know About Vaccination

The introduction of special drugs - vaccines - may be the only way to stop the pandemic spread of COVID-19. There is a lot of talk about this topic, but for a simple layman, nevertheless, there are a lot of questions, which we will try to answer.

What is COVID-19 vaccine?

The main purpose of vaccination is to prepare the body for a decent response to the penetration of an infectious agent (in particular, coronavirus). Drugs can consist of non-living (inactivated) or weak pathogens, or their particles.

The vaccine "teaches" our immunity to identify pathogenic microorganisms, to produce antibodies against it. The introduction of a biological product is not capable of causing the development of infection, but sometimes a person may experience an individual reaction, for which one needs to be prepared. Most often, such a reaction is soreness in the injection area, swelling, a slight increase in temperature. In return, a person will acquire immune protection against a specific disease.

The essence of "vaccination" is as follows: it does not cure the disease, but prevents its development.

Are COVID-19 vaccines dangerous?

Vaccination has been known to mankind since the 18th century: the first vaccination was given in 1774 by Dr. Benjamin Jesti. Since then, people have managed to eradicate many deadly diseases - in particular, smallpox. Smallpox pathogen samples in the world have been stored in only a few closed laboratories.

Scientists have not yet been able to defeat poliomyelitis, however, thanks to vaccination, the incidence rate has dropped significantly, and today pathological cases are measured in units, but not in thousands, as in the last century. The incidence of tetanus, cholera, anthrax, and diphtheria has also significantly decreased. Many people survived by getting vaccinated on time.

Today, nature has thrown a new challenge to scientists - we are talking about COVID-19. Vaccinations are also needed to stop the pandemic. However, the development of a vaccine, despite the complexity of this process, is only the first link in the chain. A biological product must undergo a thorough laboratory examination on animals, then clinical testing on humans follows, and only after that can one expect to receive approval from the relevant authorities. In some cases, a vaccine is not recognized as completely safe, but is still approved by WHO if the benefits of its administration significantly outweigh the likely risks. [1]

Rumors about the dangers of vaccines against COVID-19 emerged after a series of reports of several deaths some time after vaccination with new biologics. However, this information is not entirely correct: so far not a single death has been recorded as a direct consequence of the "vaccination". Many patients died from a sharp aggravation or exacerbation of the underlying chronic disease. Some of them had confirmed oncological diseases, renal failure, cardiovascular pathologies, etc. [2]

The PEI Medical Safety Officer confirmed that the deaths were not vaccine-related. "When elderly patients or persons with severe chronic pathologies are vaccinated (namely, with whom vaccination was started), then there is a probability of a certain number of deaths, the causes of which are not due to vaccination."

By the way, vaccines from BioNTech / Pfizer and Moderna manufacturers are still used in Germany. These products are recommended by PEI representatives as products with a very high level of safety.

Do I need to get vaccinated against COVID-19?

Experts from the World Health Organization advise everyone who has no contraindications to vaccinate. Only in this case can one count on a complete blocking of the pandemic spread of coronavirus infection.

Of course, what scares many people is that new vaccines for COVID-19 have been developed in a very short time. We can agree with this, because usually it takes years to develop a new biological product. Scientists explain that the high rate of vaccine emergence is due to the active cooperation of many highly qualified specialists who have thrown all their efforts into the fight against the pandemic. [3]

How are current COVID-19 vaccines different?

Vaccines from the manufacturers BioNTech / Pfizer    [4]and Moderna    [5]include the partial genetic code of the coronavirus pathogen, its messenger RNA. That is, vaccination with such drugs does not imply that a weakened pathogen enters the body, but forces the cells to produce the spike protein present on the surface of the coronavirus and activate the immune response in the form of antibodies.

The Astra Zeneca vaccine from Oxford University works in a different way, based on a modified common adenovirus that causes disease in chimpanzees. A fragment of the genetic code of the COVID-19 coronavirus was introduced into the adenovirus.  

RNA vaccines (BioNTech / Pfizer and Moderna) do not deliver the antigen to the body, but only genetic information about it. This is followed by expression of the antigen in the patient's cells. Preclinical trials of such vaccines are quite promising and successful, and the drug is produced entirely  in  vitro. The difficulty lies only in the fact that this technology is new and raises many questions in terms of large-scale production of drugs.

Vector vaccines are based on vectors of the virus that display a spike protein on their own surface and are inactivated before use. As a result, vectors become less dangerous, since they lose the ability to replicate even under conditions of weak immunity of the patient.  [6]

Inactivated vaccines are produced by growing the virus in cell culture, with its further chemical deactivation. [7]An example of an inactivated drug is CoronaVac. [8]

BioNTech / Pfizer, Moderna and Astra Zeneca vaccines are approved for use in the United States and the United Kingdom. Vaccination has started in Mexico and Costa Rica (with BioNTech / Pfizer), and in Brazil it is allowed to vaccinate with Astra Zeneca vaccines and the Chinese product Sinovac.

For comparison, the table lists some of the most popular COVID-19 vaccines (as reported by UK sources):

Moderna	Contains messenger RNA (a particle of the genetic viral code)	Two doses of the drug are required	Efficiency according to expert judgment is more than 94%	Storage for seven months at -15 to -25 ° C
BioNTech / Pfizer	Contains RNA	Two doses of the drug are required	The efficiency is 95%	Storage for six months at -60 to -80 ° C
Oxford-Astra Zeneca	Contains a viral vector (genetically modified virus)	Two doses required	Efficiency according to expert judgment is over 70%	Storage for six months at 2-8 ° C
Sinovac (CoronaVac)	Contains a killed (weak) virus	Two doses required	The described efficiency ranges from 50 to 78%, but requires additional expert judgment.	Storage at 2 to 8 ° C
Satellite V	Contains viral vector	Two doses of the drug are required	The described efficiency is more than 91%, but requires additional expert judgment.	Storage at -18.5 ° C (liquid) or 2 to 8 ° C (dry)

The CoronaVac vaccine, developed on the basis of a neutralized virus, was approved for use in China, Indonesia, Malaysia, Singapore, and the Philippines. However, this drug has become less popular after independent studies have shown its insufficient effectiveness - about 50.4% (tests were carried out in Turkey, Brazil and Indonesia).

India has approved topical biologics Covaxin from Bharat Biotech as well as Astra Zeneca (locally called Covishield).

Russia uses its own vector drug Sputnik V,  [9]which was purchased by such countries as Argentina, Belarus, the United Arab Emirates, Hungary, Turkmenistan, Serbia, Palestine, Paraguay, Venezuela.

African countries - members of the AU - have approved the use of vaccines BioNTech / Pfizer, Astra Zeneca and Johnson & Johnson (the latter is still at the testing stage).

When is the COVID-19 vaccine contraindicated?

A person who will be injected with one of the COVID-19 vaccines should not have signs of an acute respiratory viral infection or exacerbation of existing chronic pathologies. 5 days before the injection, you should not consume alcohol and overeat fatty foods.

If you have a runny nose, cough, high fever, general disturbance of well-being, you should wait with vaccination. [10]

In addition to general contraindications, a person must have a psychological readiness for the procedure. Excessive experience, fear, anxiety can lead to an increase in blood pressure, to the production of stress hormones, which will negatively affect the cardiovascular system and can cause the development of complications.  [11]

With a tendency to allergic processes, the patient should take an antihistamine on the eve of vaccination.

In order to prevent negative consequences, many experts recommend passing a PCR test before the procedure, to exclude the latent course of COVID-19. It will also be useful to test for IgG and IgM antibodies, and after the vaccine is administered, an analysis of the level of IgG antibodies. After vaccination, the development of immune defense does not occur immediately, but after about 2 weeks. [12]

At the beginning of 2021, world scientists have already worked on two hundred potential drugs for vaccination against COVID-19. More than sixty vaccines have undergone clinical testing, and only six of them have received approval for use in different countries.