Corona Vaccines

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Corona Vaccines

Even before coronavirus broke out in 2019, pharmaceutical companies were working on designs for vaccines they could quickly adapt to a pandemic strain of virus. Their work paid off in some of the new Covid-19 vaccines. The 4 main types of Covid-19 vaccines in production are illustrated below:

        mRNA                VECTOR            PROTEIN SUBUNIT   WHOLE-KILLED

Used by:

  Pfizer,           AstraZeneca,   Novavax,       Sinovac,
  Moderna   Sputnik,   Sanofi     Sinopharm
    Janssen    
  2 Doses   1-2 Doses   1 Dose     1-2 Doses

 

 

 

 

mRNA vaccines are the newest approach. They use genetic material called messenger RNA, a kind of genetic software that instructs cells to make a piece of the coronavirus spike protein. The mRNA is coated in soft fatty lipids to protect it.

Vector vaccines use another virus to carry the genetic instructions. For the coronavirus they all use a common cold virus, called adenoviruses. They attach to cells to inject their DNA that tells the cells to make coronavirus spike protein.

Protein subunit vaccines get only pieces of the target virus, that circulate in a body for the immune system to recognize. Not the human body is the vaccine factory, but genetically engineered insect viruses are used to infect moths, whose cells then produce the pieces of coronavirus spike protein. These are harvested and made into a vaccine.

Whole inactivated virus vaccines take longer to make because batches of the coronavirus must first be grown and then killed using a chemical or heat, and then made into a vaccine that can be injected to elicit an immune response.

Here’s a look at how the different coronavirus vaccines work:

Pfizer and BioNTech

China has contributed greatly to the fight against COVID-19 pandemic, by immediately making public the genome of this virus since they were the first to fully identify it. They did not file for a patent and supplied many millions of vaccines to those countries who could not afford it, especially in Africa.

Pfizer and its German-based partner BioNTech use a new approach to making vaccines that uses messenger RNA or mRNA. This design was chosen for a pandemic vaccine years ago, because it is one that lends itself to quick turnaround. All that is needed is the genetic sequence of the virus causing the pandemic to make the vaccine.

They use a little piece of genetic material coding for a piece of the spike protein, the structure that adorns the surface of the coronavirus, giving it that studded appearance.

Messenger RNA is a single strand of the genetic code that cells can "read" and use to make a protein. In the case of this vaccine, the mRNA instructs cells in the body to make the particular piece of the virus’s spike protein. Then the immune system recognizes it as foreign, and is prepared to attack when actual infection occurs.

mRNA is very fragile so it’s encased in lipid nanoparticles, a coating of a buttery substance that can melt at room temperature. That’s why this type of vaccine must be kept at ultracold temperatures of -75° C. That means special equipment is needed to transport and store this vaccine.

Moderna

Moderna’s vaccine is also based on mRNA, and codes for cells to make a piece of the spike protein. Their scientists wanted to pick a piece of the virus they thought would not mutate, or change much, as time passed.

The virus uses the spike protein to grapple the cells it attacks and the structure does appear to remain stable through generation after generation of viral replication. Its vaccine has to be shipped at -20° C and then be kept stable for 30 days at 2 – 8°C in a standard refrigerator.

AstraZeneca

Their vaccine is called a vector vaccine. It uses an adenovirus to carry the spike protein from the coronavirus into cells.

It aims to make people’s bodies to produce their own vaccines by churning out little copies of spike protein, but the delivery method is different. This adenovirus doesn’t make people sick. It was modified to not replicate itself, and genetically engineered to inject cells with the DNA encoding for the full coronavirus spike protein.

It’s a cheaper way to make vaccines, but slower than using RNA. The vaccine can be kept stable for 6 months at standard refrigerator temperatures.

Sputnik V

Russia’s Sputnik V was the 1st coronavirus vaccine on the market. It is an adenoviral vector vaccine that uses two common cold viruses, adenovirus 5 and 26, to carry the genetic material for the spike protein into the body.

Since Sputnik V is a ‘vaccine cocktail’ of 2 separate vectors, the 1st and the 2nd, "booster", injection are entirely different. This approach generates a more sustainable immunity compared to vaccines that use the same delivery mechanism for both shots.

JJ’s vaccine arm Janssen Pharmaceuticals

Janssen’s coronavirus vaccine is a recombinant vector vaccine. It uses an adenovirus but it does infect humans. It is a genetically engineered version of adenovirus 26, which normally causes the common cold, but the gene tinkering has disabled it. It also delivers the genetic instructions to make spike protein. People will get two shots, 57 days apart.

Novavax

USA biotechnology company Novavax specializes in "protein subunit" vaccines. They use virus-like nanoparticles as a base and cover them with genetically engineered pieces of the coronavirus spike protein.

This is also a tried and true vaccine approach. A hepatitis B vaccine given to newborns is a protein subunit vaccine, as is the human papillomavirus or HPV vaccine and FluBlok, Sanofi’s influenza vaccine.

Novavax uses an insect virus called a baculovirus to get the coronavirus spike protein into moth cells, who then produce the protein. This is harvested and mixed with an immune booster (adjuvant), based on saponin, from soap bark trees.

Sanofi and GlaxoSmithKline

This is also a protein subunit vaccine, using Sanofi’s FluBlok technology with a GlaxoSmithKline adjuvant. It also uses a baculovirus to grow little bits of spike protein.

Sinovac and Sinopharm

Two Chinese companies use an inactivated virus, which is one of the oldest methods for vaccinating people. Whole batches of coronavirus are grown, "killed" and then made into vaccine.

This approach proved to be effective in other vaccines, such as polio and flu shots, and also against C-19 Delta variant. Their coronavirus vaccines employ an inactivated whole virus to prompt the body to develop immunity, and only need to be stored at standard refrigerator temperatures of 2Ëš- 8ËšC.

CanSino’s vaccine, which uses a common cold virus called adenovirus 5 to carry genetic fragments of coronavirus into the body, can also be kept at 2Ëš- 8ËšC.

Still, the required temperatures must be maintained throughout transport, from leaving the production facility to airport storage and finally to global distribution.

Cainiao, the logistics arm of giant Alibaba, will help with the distribution of the Chinese vaccines as soon as they’re given the go ahead. Its end-to-end climate-controlled infrastructure is in place and ready.

They have partnered with Shenzhen Baoan International Airport, which has the IATA certification for pharmaceutical logistics. A cold-chain warehouse was converted to store coronavirus testing kits, and now vaccines. It will make Shenzhen a "Covid-19 vaccine global delivery base."

Cainiao is also in partnership with Ethiopian Airlines, which will be sending the Chinese vaccines to the Middle East and then Africa. They have already flown more than 3,000 tons of medical supplies from Shenzhen to Europe, Africa, the Middle East and South America.

In the western world, what counts is what you say. In the eastern world (China), what counts is what you do.