American taxpayers are funding six Covid vaccines. This is how they work

That’s a lot of money. It is more than half of the annual budget for the state of Vermont. It’s about what Louisiana spends on its Medicaid patients in a year. But a vaccine is our surest way out of the pandemic – the surest way to get back to normal. Here is an explanation of where this money is going.

First, a brief explanation of how vaccines work.

When your body is attacked by a virus, your immune system produces antibodies to fight it. But unfortunately, it is not a perfect system, and some people still succumb to the virus.

A vaccine sends something that looks like the real virus: it can be an inactive version of the virus, or a weakened version, or maybe just part of the virus. The immune system responds as if it were something real and produces antibodies.

Theoretically, if the real virus attacks, you already have the antibodies to fight it.

The best way to attack the Covid virus

Take a look at the virus that causes Covid-19. Focus on the red spikes.

They are pretty (they look like flowers, right?) But they are deadly. The spikes adhere to the cells and the virus enters and begins to replicate. Very soon, you are full of viruses.

That’s why the six government-funded vaccine makers are trying to make their immune systems fight off the surge. If you can disable the spike, you can disable the virus.

The way to do this is to trick the immune system into letting it see a harmless coronavirus spike, one that isn’t actually bound to the virus itself. If your immune system sees that spike, you should make antibodies against it. That way, if the real virus attacks, those antibodies will be ready to fight it.

To get the spikes where they need to go in their body, almost everyone needs a delivery vehicle. Imagine the delivery vehicle as a small, small car that gets the spikes (or instructions for making them) where they should go.

Here are details on all six, sorted by how much taxpayer money they are getting.

In the end, some of these may work and some may not. We will only find out after large-scale clinical trials with tens of thousands of people.

$ 1.2 billion to AstraZeneca

How this vaccine works: AstraZeneca is using an adenovirus as a delivery vehicle. Adenoviruses cause the common cold and other diseases, but the AstraZeneca vaccine alters the adenovirus so that it does not cause harm. Inside the adenovirus, scientists have hidden genetic material that encodes the production of those red spikes. The virus is injected and, due to the inserted gene, its cells form the spikes. Your immune system makes antibodies against the spikes.

Status: The University of Oxford, which is partnering with AstraZeneca, recently started large-scale phase 3 human clinical trials in England with this vaccine. AstraZeneca plans to start testing of Phase 3 in August. Such trials are the last step before a vaccine manufacturer seeks regulatory approval.

History: Other vaccines have used this adenovirus technique, and although these vaccines have been studied in clinical trials, they have never been approved and put on the market.

$ 456 million for Johnson & Johnson

How this vaccine works: The J&J vaccine also uses an adenovirus delivery vehicle.

Status: J&J expects to start Phase 3 clinical trials in September.

$ 430 million for Moderna

How this shot works: Remember those gum machines you loved when you were a kid, the ones in restaurant lobbies? Sometimes, right next to them, there were machines that delivered small toys, like a small doll or an inflatable ball, and the toy came in a small plastic bubble. Insert the room and you will get the delivered toy in the plastic bubble. Now imagine that this plastic bubble is made of fat. That is the delivery system for this vaccine. Instead of a toy, inside that hollow ball of fat is messenger RNA, or mRNA, which is a genetic recipe for being part of the red spike. The fat bubble knows where to deliver it. Your immune system makes antibodies against the spikes.

Status: Moderna plans to begin testing Phase 3 in July.

History: Other vaccines have used this technique, and although these vaccines have been studied in clinical trials, they have never been approved and put on the market.

$ 60 million to Novavax

This vaccine involves putting the genetic blueprint for the spike into a virus that infects insects, called a baculovirus. They allow the baculovirus to infect insect cells, causing the cells to begin producing large amounts of the spike. Scientists then placed the spikes on top of a very small particle called a nanoparticle. That nanoparticle with the peaks at the top is the first part of the vaccine. The second part of the vaccine is a substance called an adjuvant, which is made from a molecule found in tree bark and food additives. When injected into the body, the immune system recognizes the adjuvant as a foreign substance and goes on high alert for infection. What he finds is the nanoparticle with the coronavirus peaks at the top. Your immune system makes antibodies against the spikes.

Status: Novavax has not yet started Phase 3 testing.

$ 38 million for Merck

Like AstraZeneca and Johnson & Johnson, Merck uses a virus as a delivery vehicle. This virus is called gallbladder stomatitis and causes flu-like symptoms, but Merck modifies and weakens it so it doesn’t get sick. Scientists insert a gene into the virus that contains instructions for making the spikes. The virus is injected and replicates in your body, and because of the inserted gene, you spike it. Your immune system makes antibodies against the spikes.

Status: Merck has not yet started human clinical trials.

History: This same technology was used to make an Ebola vaccine called ERVEBO that was approved by the FDA in 2019.

$ 30 million for Sanofi

How this vaccine works: Sanofi also starts with a gene that provides the blueprint for the spike. They take that gene and insert it into a virus called a baculovirus, and then infect an insect cell with that virus. Due to the inserted coronavirus gene, the insect cell produces the spines. The vaccine contains those spikes along with a second part, an adjuvant that contains vitamin E, which helps the immune system do its job. Your immune system makes antibodies against the spikes.

Status: Sanofi expects to start clinical trials between October and December this year.

History: This same technology that used a baculovirus was used to make a flu vaccine called Flublok, which was approved by the FDA in 2013. Several other vaccines, including those for hepatitis B and HPV, use the same technology, but they use other techniques at the baculovirus site.

If you have been following, you will notice that this amounts to only around $ 2.2 billion, not the $ 3 billion we mentioned. The United States government is awarding nearly $ 783 million to three companies to manufacture the FDA-approved Covid vaccines: Emergent BioSolutions, SiO2 Materials Science, and Ology Bioservices.

CNN’s John Bonifield contributed to this report.

This story has been updated to adequately reflect the current state of Novavax testing.