How to Make a CORONA Vaccine || Dr. Nasren Nipa

How to Make a CORONA Vaccine

Step 1: Select the vaccine target:

(1) In-Silico Target Analysis: 

It is a type of data base analysis which is done by computer using special type of software (Bioinformatics). There have been many hole-genome sequences of the corona virus since January. All sequence data has been made available on the NCBI website so that scientists can develop coronary drugs or vaccines. The earliest step in making a corona vaccine is to select one or more small parts (targets) of the corona virus gene from the whole-genome sequence that can be used to make a vaccine against the virus. 

Oxford and China are using this method to create vaccines targeting gene sequences that produce the spike protein (S-protein) of the corona virus.

(2) Viral Vector Preparation: Laboratory Activities:

Oxford and China are developing adenovirus vector-based vaccines. Adenovirus is a type of non-enveloped DNA virus that infects the human body with the common cold. This method first removes a few genes from the adenovirus (E1 and E3 genes) so that the virus can not only infect but also lose its ability to reproduce. This modified adenovirus acts as a delivery vector for the vaccine. On the other hand, DNA copies of pre-selected target genes are made by cloning using bacterial plasmid DNA. This target DNA, such as the spike protein gene, is then inserted into the adenovirus through cell culture in a special way. If the recombinant adenovirus thus infected infects a cell, it produces a spike protein like the corona virus inside that cell. This means that the mutated adenovirus then looks like a fake corona virus but cannot cause covid disease. This mutated adenovirus is used as a vaccine.

Since the gene deleted adenovirus vector and plasmid DNA are now readily available and the genome sequence of the corona virus is ready, the first step should not take more than 3-4 months to complete. 

Step 2: Vaccine Target Validation (Pre-Clinical Animal Trial):

(1) Preliminary Animal Experiment: 

In this case the adenovirus vaccine or DNA vaccine produced in the first stage is injected directly into the animal's body (such as rat, rabbit or monkey). At 14 and 28 days after the injection, the animal's blood was tested to see if the animal's body had produced antibodies against the target gene. If the test shows that within 2 of the 4 pre-selected targets, there is an immune response against 2 targets and the correct antibody is produced, then those 2 targets are selected for the next test.

(2) Animal trials of vaccines: 

Many types of animals are used in such animal trials, such as Rats, monkeys or rats.

Oxford and China (SinoVac) conducted pre-clinical animal trials of their vaccines on monkeys. American Mordana, on the other hand, tested their mRNA vaccine directly on the human body without any animal trials, because no live or inactivated virus was used in their vaccine.

Animal trials are very important in the development of traditional vaccines.This trial will show whether the vaccine is safe and effective or not. Is the animal immunized by the vaccine free from corona virus infection? The dose-dependent response of the vaccine is also observed in this trial.The vaccine (at least 2 targets) responds dose-dependent to the immune system. Such trials are time consuming.

The trial needs to show that the vaccine is capable of producing adequate amounts of the right antibodies. And those antibodies are able to inactivate the corona virus. Not only that, it need to show that the T-cell response in rats is also adequate when vaccinated.

In such animal trials, it usually takes 3-4 months to complete the entire test, starting with taking ethical permission.

Step 3: Phase I Human Trial: Dosage and Safety Check:

This is a very important trial. In this trial, at least 50-100 healthy adults and those who have never had coronavirus vaccine will be given the vaccine intramuscularly. The vaccine will usually be given in 3 doses (high, medium and low). Thenit is necessary to monitor very well whether there is any reaction. All types of side effects caused by the vaccine should be monitored. Blood antibody titers and T-cell response should be seen before and 6, 14 and 28 days after vaccination. The vaccine will be approved for Phase II trial if all of these results are good and the vaccine does not show any bad side effects.

If ethical permission is taken and all the healthy volunteers are ready, then such a trial can be completed within 2 months.

Step 4: Phase II and Phase III Human Trial:

(1) Phase II Human Trial:

 This trial will prove whether the vaccine produced can actually develop immunity against corona. In this case 300-500 healthy people of different ages will be vaccinated and they will be monitored for 2 months. It remains to be seen whether the vaccine can build immunity in their bodies. The placebo control group should also be included in this trial for comparison.

(2) Phase III Human Trial: 

This is the latest trial of a vaccine which is also the largest trial. About 10,000 to 15,000 people of different ages and tribes were included in the trial. With the vaccine, they are allowed to move around the community without any preventive measures. Thus, they were monitored for at least 2/3 months and it was seen how many corona were infected inside the vaccine recipients and how many corona were infected in the control group. If the vaccine has been shown to prevent coronary infections, then it is safe to say that the vaccine was effective. After that vaccine production will be started.

Current situation of CORONA Vaccine production:

The Oxford vaccine is now being tested in Phase III on about 20,000 people in at least three countries. Their trial will end in September. 

AstraZeneca will make their first batch of 30 million doses of vaccine for the UK by the end of September, followed by another 70 million.They will then deliver 400 million doses to the United States and 400 million doses to Europe.

Mordana is very optimistic about bringing their mRNA vaccine to market by June next year. 

China also wants to bring their vaccine very soon.

              We need vaccines, not just for corona, but for many more diseases. In that case, if it is produced early, it is a great thing, a matter of life saving from CORONA VIRUS.