Vaccines against COVID-19: everything you need to know about them

Vaccination has saved humanity more than once. One of the most successful examples is vaccination against smallpox, an infectious disease that claimed the lives of over three hundred million people worldwide in the 20th century alone. Almost everyone died in severe pain, and those who remained alive often lost their sight. No cases have been reported since 1967, thanks to the WHO mass smallpox vaccination program.

Today, our planet is struggling with an equally serious disease - COVID-19, which dramatically changed the lives of many people about two years ago. Since the beginning of the pandemic, scientists and doctors around the world have begun developing vaccines that can create immunity, prevent the disease, or significantly reduce the symptoms of its course.

As of December 2020, more than 200 COVID-19 vaccines were in development. A fourth of them have reached clinical trials involving humans, the rest either have not proven their effectiveness in laboratory animals, or are still in the first phase of experiments. Only after confirmation of the effectiveness of the vaccine in laboratory animals, the second and third phases are carried out - clinical trials and the study of the properties, side effects and other important characteristics of the biological product.

Such a large number of developments increases the likelihood of creating an effective and safe vaccine, because no more than 10 anti-COVID-19 drugs reach the finish line. And today, most of them have already been introduced into vaccination protocols around the world.

What types of coronavirus vaccines are there

All means for vaccination, including against COVID-19, can be of several types depending on manufacturing method: inactivated, live attenuated, viral vector, subunit, based on genetic material.

Several approaches have been used in the development of coronavirus vaccines, so patients can choose one of five options to obtain immunity from this disease: CoronaVac, AstraZeneca, Moderna, Pfizer/BioNtech, Sputnik V

CoronaVac

Manufactured by the Chinese pharmaceutical company Sinovac in cooperation with the Indonesian corporation Biofarma, as well as the Brazilian testing institute Butantan. According to the approach to manufacturing, the vaccine belongs to the whole-virus inactivated and is created on the basis of pathogenic viruses and bacteria that are inactivated by heat, radiation or chemical treatment. This technology has proven effectiveness, and most importantly, given the non-infectiousness of microorganisms, the vaccine is not capable of causing disease.

This method of making vaccines has been used for decades, therefore it is the most studied and understood. Many doctors say that this is one of the advantages of CoronaVac, because after intramuscular injection, an immune response is quickly developed.

Clinical trials of the vaccine by the manufacturer confirm its effectiveness in 50.38% of patients. Turkish doctors claim that it works in 90% of cases.

AstraZeneca

The vaccine was developed by the British-Swedish company AstraZeneca together with the University of Oxford. It belongs to the group of viral vector vaccines, because it is made on the basis of a weakened adenovirus that causes a cold in chimpanzee monkeys. Such a virus is completely safe and performs the function of a "transporter" of virus proteins - it is into it that the code for the formation of a pathogen is introduced, when it enters the body, an immune reaction develops.

AstraZeneca's vaccine developers noticed a pattern during their trials: efficacy is dose dependent. With the introduction of two full doses at a certain interval, the vaccination is effective in 90% of patients. If the first time you enter half the dosage, and the second - the full, the effect will be at the level of 62%.

Moderna, Pfizer/BioNtech

Two types of these vaccines belong to the group of drugs based on genetic material. They are similar to each other, since ribonucleic acids are used for manufacturing. This technology has been known for a long time, but in practice, permission for their use was obtained for the first time.

Such drugs, during the vaccination process, deliver a set of instructions in the form of mRNA to the human body, inducing protein synthesis, to which the immune system must respond.

Moderna is the American version of the coronavirus vaccine. Manufactured in Massachusetts. The manufacturer, based on test data from volunteers, claims that the vaccination is 94% effective.

Pfizer/BioNtech jointly launched the American concern Pfizer and the German pharmaceutical company BioNtech. The developers claim that 28 days after the first dose, the effectiveness of the vaccine reaches 95%. At the same time, there is one caveat: in patients older than 65 years, it is somewhat reduced. Pfizer/BioNtech is one of the first vaccines used to immunize the population.

Sputnik V

Adenovirus-based vector vaccine developed and produced in Russia. Its clinical trials took place not only at home, but also in the United Arab Emirates, Venezuela, India and Belarus. The manufacturer assures: the efficiency of the Sputnik is 97.6%.

For its production, heterogeneous boosting is used, that is, each of the doses has different vectors. Russian scientists working on the vaccine believe that this approach allows for longer immunity, because the two types of adenoviruses reinforce each other.

Possible side effects of vaccination against COVID-19

Opponents of vaccination argue their position with serious side effects after the use of created vaccines. But in fact, the prevalence of life-threatening and health-threatening symptoms is low.

Before a vaccine or after a procedure, doctors warn patients that possible side effects are not only a reaction of the immune system, but also of other body systems. And it is quite normal if there is:

  • redness, swelling or pain at the injection site;
  • headache, muscle, joint or abdominal pain;
  • gastrointestinal disorders - nausea, diarrhea ;
  • chills, fever ;
  • insomnia;
  • dizziness;
  • fatigue.

Such side effects disappear within a few days, so it is enough to monitor your body, do not bring the temperature down to 38.5 degrees and in no case take antibiotics.

Allergic reactions are possible with coronavirus vaccination, but they often occur in the first minutes after a dose. That is why it is recommended to wait at the vaccination point for 15-25 minutes in case of need for emergency medical assistance.

It is important to remember that you should immediately contact a doctor or an ambulance if, after a vaccine injection, the patient feels a serious illness: severe headache, fever, loss or confusion, vomiting, convulsions.

Vaccination: for or against

In the first wave of coronavirus, almost daily, the Ministries of Health of the countries facing the epidemic reported the death of more than 500 patients per day. During the vaccination campaign, for example, in Ukraine, this figure dropped to 103 people in 7 months. The difference is significant, so only from this can we conclude that grafting gives a result.

It is also worth considering that before use, all vaccines must:

  • are carefully tested for safety;
  • are undergoing three mandatory phases of clinical trials;
  • follow strict clinical guidelines.

And finally, for the pandemic to weaken its position, it is necessary to create herd immunity, for which 80% of the population must be vaccinated. The evidence that the scheme worked was polio vaccination. Definitely worth fighting in this way with COVID-19.

Sources