Vaccine Update on New Coronavirus in a Nutshell (June 2021)

The latest information on vaccines for new coronaviruses explained in simple terms

'There are vaccines from many different companies, what's the difference?' 'Once vaccinated, how well does the vaccine work?' 'Why am I scared of the Indian type (delta)?' This article addresses these questions.
We have compiled credible primary information from public institutions and research institutes.

Understanding vaccines protects your health and assets.

Proper knowledge of vaccines will protect your assets and health.

This is because there has been an increase in fraudulent activity related to the new coronavirus.

For example, in Japan, the National Consumer Affairs Center is receiving an increasing number of inquiries.

In the U.S., fake remedies are also being warned against.

I do not want you, who are reading this article and trying to get the right knowledge, to be fooled by any means.

Proper knowledge of vaccines will help you avoid unapproved drugs and scams.

Three vaccines approved in Japan (June 2021)

In June 2021,

  • Vaccines from Pfizer/BIONTECH
  • AstraZeneca Vaccines
  • Modela Vaccines

Three types of vaccines are approved in Japan.

The first vaccines to begin being administered were those produced by Pfizer/ BIONTECH.

Vaccinations began on February 17, 2021, mainly for health care workers.

On May 21, 2021, vaccines from Modela and AstraZeneca were approved.

The situation is that the vaccine from Moderna has been available since May 24, 2021.

As discussed below, Pfizer/BIONTECH's vaccine and Modela's vaccine are mRNA vaccines.

AstraZeneca's vaccine is called a viral vector vaccine, which is manufactured differently from mRNA vaccines.

Vaccinations are said to cause blood clots in AstraZeneca vaccines.

Furthermore, the Johnson & Johnson vaccine that we have been seeing in the media lately is still in the application process and not yet in supply.

[How Vaccines Work] Vaccinations are given to make the body produce antibodies.

Vaccines approved in Japan are given for the purpose of [making the human body produce antibodies].

This is because the presence of antibodies against the virus in the human body makes it more difficult for humans to develop novel coronavirus infections.

Antibodies are proteins that neutralize viruses when they enter the body.

The purpose of the three vaccines is [to make the human body produce antibodies], but they differ in how they achieve that purpose.

There are two ways to achieve the objective: mRNA (messenger RNA) and viral vectors.

This section describes how mRNA vaccines and viral vectors vaccines work.

Infection and disease onset are not required to produce antibodies

The condition for the human body to produce antibodies is to be infected with and develop a new type of coronavirus.

However, you do not want to be infected with or develop a new type of coronavirus for that reason.

Vaccines were developed in the search for a way to make the human body produce antibodies to the new type of coronavirus without infection or disease onset.

In other words, the body does not necessarily need all of the new coronavirus to produce antibodies.

Vaccination is to make the body produce spike proteins

Vaccines are a way to get the blueprint of the spike protein*1 into the human body.

To produce antibodies against novel coronaviruses, the human body must recognize the spike protein of the novel coronavirus.

Therefore, spike protein must be placed in the human body.

When the blueprint for the spike protein is put into the body, the human body creates the spike protein based on the blueprint.

Then, using the spike protein as a marker, the human body produces antibodies that can prevent infection and development of the new coronavirus.

1 Spike protein: A protein on the surface of novel coronaviruses. The spike protein allows the virus to infect humans.

The difference between mRNA vaccines and viral vector vaccines is the way they are carried

The vaccine was a tool to put a blueprint of the spike protein into the human body and make it produce antibodies.

The difference between mRNA vaccines and viral vector vaccines is the way the blueprint is carried.

Spike proteins cannot be made from the blueprint unless they are transported to the human cell.

mRNA vaccines spike protein information in lipid membranes (lipid nanoparticles).

The viral vector vaccine carries the blueprint to the cell by placing the spike protein information in the chimpanzee adenovirus.

Advantages and disadvantages of mRNA vaccines

The benefits of mRNA are

  • Production takes less time
  • Vaccination does not cause new coronavirus infection.
  • No fear of your DNA being rewritten by mRNA

The reason for the shorter production time is that unlike conventional vaccines, viruses do not need to be cultured.

The mRNA vaccine contains only information on the spike protein on the surface of the novel coronavirus.

That information alone does not produce the symptoms that appear with new coronavirus infection.

The mRNA vaccine is degraded in a few days.

Since it does not stay in the human, it is said that the information on the spike protein is not incorporated into human DNA.

However, as a disadvantage,

  • May have unintended side effects
  • Hard to store and manage

The following is a list of the most common reasons for this.

Advantages and disadvantages of viral vector vaccines

What are the advantages of viral vector vaccines?

  • Vaccination does not cause new coronavirus infection.
  • Easier to store and manage than mRNA

In contrast, the disadvantage is the case of immunity to the viral vector.

If this happens, the vaccine will be eliminated from the body before the human can produce antibodies.

Furthermore, if immunity is created after the first vaccination, the second vaccination may also be eliminated from the body and the vaccine may not be fully effective.

Effectiveness and duration of vaccine

All three vaccines have high efficacy rates.


  • Pfizer/BIONTECH: 94.6%.
  • 94.1% for Moderna
  • AstraZeneca 70.4%.

The vaccine is said to last about 6 months.

According to data published by Modela, antibodies remain in the body even 180 days after the second vaccination.

Six months after the people in the clinical trial, Pfizer also studied the effect of preventing the onset of the disease.

The results show that the effectiveness in preventing the onset of disease remains high at 91.3%.

How much difference is there between different types of vaccines?

The mRNA vaccine has an efficacy rate of more than 90%.

Viral vector vaccines also have higher efficacy rates than influenza vaccines, exceeding 70%.

The three approved vaccines, other than the efficacy rate in this item,

  • Pfizer/BIONTECH (mRNA vaccine)
  • Modela (mRNA vaccine)
  • AstraZeneca (viral vector vaccine)

The following is an explanation of what differences there are between the two.

Differences in manufacturing methods

Modela and Pfizer/ BIONTECH

The information from the spike protein is wrapped in a lipid membrane.

This is because mRNA is very unstable and fragile.

The lipid membrane is responsible for protecting the mRNA.

AstraZeneca Pharmaceuticals, Inc.

Incorporate spike protein information into the chimpanzee adenovirus.

Adenovirus is treated so that it does not increase in the human body.

The reason for using chimpanzee adenovirus is that humans are not immune to it.

Humans are immune to human adenovirus and try to eliminate adenovirus.

However, in the case of chimpanzee adenovirus, it is not eliminated and can enter cells.

Handling Method

The temperature at which mRNA vaccines and viral vector vaccines can be stored is different.

mRNA vaccines are more delicate and difficult to handle and require storage at lower temperatures.

At 2-8°C, Pfizer/ BIONTECH's vaccine can be stored for 5 days and Modela's vaccine for about 30 days.

Furthermore, for long-term storage, it should be stored below -20°C (-4°F).

In contrast, AstraZeneca's vaccine (viral vector vaccine) can be stored at 2-8°C for up to 6 months.

It is similar in administration to the influenza vaccine and is expected to be easily disseminated.

adverse reaction

Adverse reactions common to all three vaccines are,

  • Pain at the vaccination site
  • washed-out feeling
  • headache
  • generation of heat
  • myalgia

In addition to the above, anaphylactic shock has also been observed with Pfizer/BIONTECH and Modela vaccines.

There is a rare adverse reaction to AstraZeneca's vaccine, 'blood clots'.

A blood clot is a clot or sludge of blood.

The presence of blood clots in the blood can slow the flow of blood and lead to a variety of diseases.

What is a blood clot, arising from AstraZeneca's vaccine?

TTS is rare with AstraZeneca vaccines.

TTS is Thrombosis with Thrombocytopenia Syndrome, thrombosis with thrombocytopenia after vaccination.

TTS is said to develop 4 to 28 days after vaccination,

  • thrombosis
  • thrombocytopenia
  • Abnormal markers of coagulation-fibrinolytic system
  • Detection of anti-platelet factor 4 antibodies

is considered to be a feature.

TTS occurs infrequently, at a rate of 1 in 10,000 to 100,000.

TTS causes severe cerebral venous thrombosis with hemorrhage and cerebral edema as symptoms, and the fatality rate is very high.

inoculated person

Modela and AstraZeneca vaccines are 18 years and older.

Beginning in June 2021, Pfizer began offering vaccinations for ages 12 and older.

Vaccine Development and Licensing Flow and Process

Once a vaccine is developed, it is not immediately available for distribution.

It is supplied to us over a long period of time.

However, compared to conventional vaccines, the vaccine for novel coronaviruses came into supply in a shorter time.

This section describes the differences between the novel coronavirus vaccine and the conventional vaccine.

Flow of conventional vaccines to supply

Until the vaccine supply,

  • basic research
  • nonclinical study
  • clinical study
  • Regulatory Applications and Examinations
  • approval

is the general flow.

Basic research is the stage of deciding what to use to perfect a vaccine.

Conventionally, the virus was weakened and propagated as a vaccine (attenuated or inactivated vaccine).

Achieving this took a lot of time, including propagating the virus.

Non-clinical testing is a method of using vaccines that have been perfected through basic research on cells and animals to see the results.

Based on this study, the dosage to be administered to humans will be roughly determined.

Clinical trials are the process of actually inoculating humans, usually in three phases, from phase 1 to phase 3.

Phase 1 is administered to a small number of healthy humans.

Phase 2 will begin dosing a small number of humans who will be targeted for the vaccine.

In phase 3, based on the results obtained by phase 2, a number of vaccine targets were dosed.

and check the results.

Generally, this is called a clinical trial.

Regulatory application and review is an application to the Ministry of Health, Labour and Welfare based on data obtained from clinical trials.

The Ministry of Health, Labor and Welfare (MHLW) conducts the review, which takes approximately one year or less on average.

After the above process, the vaccine has been approved for use and supplied to us.

Vaccine Flow of the New Coronavirus

The major difference from conventional vaccines is that each process is carried out in parallel, shortening the time required.

For the new coronavirus vaccine, basic research and clinical trials were conducted simultaneously to shorten the time required for regulatory filing.

Next, mRNA vaccines can quickly complete the basic research phase.

This is because there is no period of time to incubate the virus as in the past.

Furthermore, the MHLW has shortened the review period compared to conventional vaccines.

As for the production of vaccines, the government is also providing assistance to development companies to speed up the process.

The government bears the risk of the developing company, and R&D and production are conducted in parallel.

As part of the "Accelerated Parallel Plan," the Ministry of Health, Labor and Welfare (MHLW) has taken the unusual step of bringing a vaccine for the new coronavirus to fruition as soon as possible.

Infection with novel coronavirus (COVID-19) produces antibodies

As with vaccines, antibodies are produced when infected with novel coronaviruses.

However, according to the Ministry of Health, Labor and Welfare, 'antibodies can be produced, but it is not clear how long antibodies can be produced.

There are several reports regarding the length of time antibodies remain in the body.

According to reports from Yokohama City University and the Japan Agency for Medical Research and Development, antibodies are maintained for 3-6 months.

On the other hand, Osaka University has reported that antibodies that enhance infection (infection-enhancing antibodies) are produced, rather than antibodies that nullify the effects of the virus.

Why is the Indian type (delta) such a threat?

Why do you feel threatened by the Indian type (delta)?

  • Scenes of India's Medical Collapse Amplify the Threat
  • In animal studies, virulence is higher than conventional viruses
  • Especially to Japanese, Indian type (delta) is suggested to be more infectious.

India averages more than 300,000 to 400,000 new infections per day and more than 300,000 deaths in a pandemic.

The number of medical oxygen and medicines is inadequate in the medical field.

Experiments were conducted on hamsters, not on humans, regarding pathogenicity.

This is an experiment in which hamsters were inoculated with a conventional new type of coronavirus and an Indian type (Delta).

As a result, the virus was reported to be more virulent than conventional novel coronaviruses.

The Indian type (delta) is characterized by [double mutation].

Double mutation is an event in which the L452R and E484Q mutations occur simultaneously in the spike protein of a novel coronavirus.

[Double mutations] are said to increase infectivity because of their ability to escape human immunity.

Why is it more infectious to the Japanese?

This is because the new coronavirus escapes from the immune systems of many Japanese people.

Sixty percent of Japanese people have a white blood cell called HLA-A24.

White blood cells are the cells responsible for immunity, and "HLA-A24" is the blood type of white blood cells.

In other words, the Indian type (delta) [double mutation] has the ability to easily escape from "HLA-A24," so the Indian type (delta) is considered to be more infectious for 60% of the Japanese population.