Following AstraZeneca (AZ), Pfizer’s COVID-19 vaccination has also started in Korea today (27th), and interest is drawing on its efficacy, side effects, and vaccination method.
According to the health authorities, the Pfizer vaccine, which entered Korea yesterday through the COVAX facility, an international project for joint vaccine purchase, will be vaccinated by medical staff at the forefront of Corona 19 from today.
A total of 300 people are eligible for the first vaccination, including 199 workers at the National Medical Center and 101 workers at the treatment hospital for COVID-19 patients in the metropolitan area.
Pfizer’s vaccine’Cominati’ is a’nucleic acid vaccine’ that utilizes messenger ribonucleic acid (mRNA, messenger RNA) containing the genetic information of the virus.
It was jointly developed by Pfizer in the United States and Bioentech in Germany.
The antigenic gene of the Corona 19 virus is injected into the body in the form of mRNA to produce an antigenic protein, thereby inducing an immune response.
Previously, the Ministry of Food and Drug Safety examined the safety and effectiveness of the vaccine through a phase 3 clinical trial conducted in six countries, including the United States, and found that the prevention effect was 95%.
Even including the elderly and those with underlying diseases, more than 94% of the preventive effects were achieved.
However, for severe COVID-19 prevention, the total number of occurrences was small, so there was no statistical significance.
All vaccinated people have more than four times increased their “antibody titer,” an antibody titer capable of responding to the Corona 19 virus antigen.
The titers of’neutralizing antibodies’, which neutralize viral infectivity and induce a preventive effect, also increased more than four times.
Most of the local and systemic adverse reactions observed mainly in clinical trials were mild and disappeared within 1 to 2 days after onset.
Local reactions included pain at the injection site (84.1%), swelling (10.5%), and redness (9.5%).
Systemic reactions such as fatigue (62.9%), headache (55.1%), muscle pain (38.3%), and chills (31.9%) were also observed.
In addition to the common symptoms, there were 4 cases of acute facial palsy.
Allergic reactions have been reported during post-clinical large-scale vaccinations.
When the Pfizer vaccine was vaccinated against 1893,000 people including health care workers in the United States on December 14-23 last year, 0.2% (4,393 people) had an allergic reaction.
Of these, 175 cases that were likely to be severe were reviewed, and as a result, 21 had’anaphylaxis’ and 83 had allergic reactions to vianaphylaxis.
Anaphylaxis is a sudden systemic reaction that occurs within minutes or hours due to certain foods or drugs.
The rest were fainting or anxiety regardless of allergies.
MRNA vaccines such as Pfizer have the advantage of being able to mass-produce within a short period of time due to their short manufacturing period, but they are considered to be a bit tricky to manage.
First of all, since the main components are easily decomposed, the stability is not good, so a cryogenic cold chain is required for distribution and storage.
In addition, it must undergo a pre-use process such as thawing and dilution.
The storage conditions of Pfizer vaccine are -60 to 90 degrees Celsius and can be refrigerated until 5 days before the first use.
The validity period is 6 months.
This vaccine should be given two doses of 0.3 ml at a time.
The second vaccination is given 3 weeks after the first vaccination, and the preventive effect appears 7 days after the second vaccination.
Vaccination targets are 16 years of age or older, but children and adolescents under the age of 18 are currently excluded from vaccination in Korea.
Final vaccination targets, etc. are determined after the final approval result of the Ministry of Food and Drug Safety and the deliberation of the Vaccination Committee of the Korea Centers for Disease Control and Prevention.
This Pfizer vaccine is for Corona 19 medical staff.
The government today plans to give the first vaccinations to 300 medical staff at the National Medical Center, followed by a series of vaccinations at corona 19 vaccination centers and hospitals dedicated to infectious diseases.
The first vaccination for all 55,000 medical staff treating COVID-19 patients will be completed on the 20th of the following month.
The second vaccination is expected to end on April 10th, three weeks later.