Vaccination against COVID-19 – what do we currently know about the vaccines? (2)

Approved types of COVID-19 vaccines

In December 2020, inactivated vaccines (currently from Chinese producers), live adenoviral vector vaccines and genetic mRNA vaccines were regionally approved for vaccination against COVID-19. At the beginning of January 2021, one of the genetic vaccines was approved by the World Health Organisation (WHO), thus helping to launch global vaccination against COVID-19.

Vaccination against the coronavirus in the Czech Republic

Since the end of 2020, we have had one variant available in the Czech Republic, namely a genetic mRNA vaccine called Comirnaty, which is produced by Pfizer. It is a different kind of vaccine than we have been accustomed to, which could raise unfounded doubts about its safety.

There is a lot of misinformation about vaccines going around. Therefore, we emphatically recommend that you always take into account exclusively information from verified and credible sources. The most discussed issue is whether administration of this vaccine can affect human DNA or RNA. The explanation is simple – a property of messenger RNA (mRNA) in the vaccine is its short-term survival in host cells; mRNA usually breaks down in the cells over the course of four to six days. Therefore, it is not necessary to worry that the vaccine can in any way change the original human genetics. You can learn more about the mRNA vaccine and its effects on the body and how it works below.

How and when can people be vaccinated against the coronavirus in the Czech Republic?

Blanket vaccination is being carried out in multiple phases in the Czech Republic. The individual phases are determined by a decree of the Ministry of Health of the Czech Republic.

Is vaccination against COVID-19 mandatory?

Vaccination against the coronavirus is understandably not mandatory. Registration for vaccination is done in the Central Reservation System (since mid-January 2021 for high-risk groups), where those who are interested in being vaccinated are subsequently assigned a vaccination date. Those who need assistance with registration or do not have access to the internet can call the information line at 1221. An employee will fill out the registration form remotely by telephone.

Development of mRNA vaccines

Though mRNA technology is new, it is not unknown, as scientists have been focusing on its development for 30 years. This technology was previously used in the preparation of vaccines against various viruses (influenza, Zika virus, rabies and cytomegalovirus) and even against certain types of cancer. Although it was unstable at the beginning of clinical studies, technological advances have led to stability, safety and efficacy over time. Incidentally, mRNA vaccinations are commonly used in oncology, for example.

How does the mRNA vaccine work against the coronavirus?

The genetic vaccine serves to prevent the disease caused by the SARS-CoV-2 virus (COVID-19) in people over the age of 16. Vaccination prepares the body to be able to defend itself against the coronavirus. The vaccine contains only a molecule known as mRNA, which contains instructions for the formation of a so-called spike protein, i.e. a protein on the surface of the SARS-CoV-2 virus that the virus needs in order to enter the cells of the human body.

When the vaccine is administered, some human cells receive instruction from the coronavirus mRNA and will temporarily form a spike protein on the cell surface. The vaccinated person’s immune system will then recognise this protein as a foreign substance, form antibodies against it and activate T-cells (white blood cells) to defend the body.

When encountering the actual SARS-CoV-2 virus, the vaccinated person’s immune system will recognise the virus. The person’s body will thus be prepared to effectively guard against it. Note, however, that the mRNA from the vaccine does not remain in the vaccinated person’s body – it starts to break down soon after vaccination. The vaccine does not contain the actual virus and thus cannot cause COVID-19. The vaccination is administered in two doses at a minimum interval of 21 days (usually injected into the muscle of the upper arm).

 
How effective is the mRNA vaccine against the coronavirus?

Extensive clinical evaluation has shown that the genetic vaccine is truly effective in preventing the onset of COVID-19 in people over the age of 16 – it has been shown to be 95% effective. Furthermore, it is also approximately 95% effective in vaccinated persons with a high risk of developing a serious case of COVID-19, including patients with asthma, chronic lung disease, diabetes, high blood pressure or a high body mass index.

How long the protection provided by the vaccine will last has not yet been documented, nor has the effect of vaccination on the community spread of SARS-CoV-2. Therefore, it is not yet known exactly how many vaccinated people may continue to transmit the virus. The same efficacy of the mRNA vaccine (approximately 95%) has been demonstrated in both genders and in all racial and ethnic groups.

Who can and cannot be vaccinated with the mRNA vaccine 

• Persons who have already been infected with COVID-19 – even though there is not sufficient data at this time, it is expected that the vaccine will be effective even in these cases. At present, the methodology requires that persons who have been infected with COVID-19 should not be vaccinated for 90 days from the date of diagnosis.
• Children – the vaccine is currently not recommended for children under the age of 16. However, a clinical evaluation of the vaccine’s suitability for children in a later phase is planned.
• Persons with weakened immunity – though the data are limited, there are currently no particular concerns with respect to such individuals. It is thus possible to vaccinate them despite their condition, especially because they may be at greater risk of contracting a serious form of COVID-19.
• Pregnant and breastfeeding women – studies have not shown any dangerous effects during pregnancy; however, the data are very limited. In the case of breastfeeding women, no risk is anticipated, though no specific studies have been carried out.
• Persons with allergies – the vaccine should not be administered to persons who are allergic to any of the components of the vaccine. Allergic reactions have been recorded and a very small number of cases of anaphylaxis have occurred. Therefore, it is necessary to administer the vaccine under a doctor’s supervision, just like other vaccines.
• Persons with an acute infectious disease – the vaccine cannot be administered in this case. It is necessary to postpone vaccination to two (though ideally four) weeks after the patient has recovered.
• Person with a rare genetic disease – such individuals should be excluded from vaccination due to the absence of knowledge about the interference of the mRNA contained in the vaccine.
  
  

Benefits of the mRNA vaccine vs. side effects and risks

The vaccine provides a high level of protection against COVID-19, which is essential at this time. The main clinical evaluation has shown that the vaccine is 95% effective, while most of the side effects are the same as those found with other vaccines and subside in a few days. The most common side effects include pain and swelling at the point of injection, fatigue, headache, muscle and joint pain, chills and elevated temperature, and exceptionally fever. Redness at the point of injection and nausea have appeared less frequently. Rare side effects include itching at the point of injection, pain in the limbs, enlarged lymph nodes, difficulty sleeping and faintness. Acute peripheral paralysis of the facial nerve has occurred very rarely.

Allergic reactions, including a very small number of serious allergic reactions (anaphylaxis), have also occurred. It is understandably necessary to administer the vaccine under a doctor’s supervision, which is true of any other vaccine. The vaccine’s benefits thus outweigh its risks and it has therefore been conditionally registered for use in the EU. More information will become available over time and data on the vaccine will be updated.

What is an adenovirus vaccine and how does it work?

Another type of vaccine in the approval process is the adenovirus vaccine developed by AstraZeneca in cooperation with Oxford University. To date, this vaccine has been approved for use in Great Britain. Its main advantage consists in easily fulfillable storage conditions. The vaccine can be stored at a temperature of 2-8°C. The genetic vaccine from Pfizer/BioNtech, which requires long-term storage at the very low temperature of -70°C, can be stored at the higher temperature of 2-8°C for only five days. The MODERNA vaccine can be stored long-term at a temperature of -20°C and can be stored at a temperature of 2-8°C for approximately 30 days.

The AstraZeneca vaccine uses an adenovirus to transmit information on the spike protein to the cells of the human body. Information for the spike protein, which forms on the surface after penetrating the cell, is inserted into the genetically altered adenovirus. The immunological response is the same as in the case of administering the mRNA vaccine.

To get vaccinated, or not?

Vaccination against the coronavirus is not mandatory. Every adult individual can freely choose to get vaccinated or not. Of course, an exception is the above-mentioned groups of persons for whom vaccination is not currently being considered.

However, the most important thing is the fact that a vaccine exists and in the near future it will be possible to get vaccinated with a vaccine working on a different principle. We thus have the possibility to choose. And mainly, it is necessary to remember that vaccination is the only thing that can change the current situation. By getting ourselves vaccinated, we will increase the vaccination rate, thus not only those who have been vaccinated, but also those who cannot be vaccinated will be protected.