Your Guide To Deciphering The Info About Different COVID Vaccines

by Elaine Roth
Originally Published: 

The vaccines are coming. The vaccines are coming.

It’s become my mantra, the thing I’ve been telling myself every day for the nearly year-long pandemic, the truth that makes me believe this pandemic-life isn’t permanent. And now, the vaccines are here.

As of this writing, two vaccines—the Pfizer and Moderna vaccines—have been granted emergency approval by the FDA. And more are coming down the pipeline. Frankly, it’s exciting and inspiring; to see what science can do when the greatest minds come together is nothing short of remarkable.

In tandem with all that excitement, as different vaccines are approved and become available (soon!) to the general public, it’s important to understand the differences and similarities between the vaccines.

What Vaccines Are Approved And Which Ones Are Coming?

At least 64 vaccines are in the process of being tested or approved. In America, only the Moderna and Pfizer vaccines have been issued emergency approval. The rollout for both vaccines has started and healthcare workers around the country are receiving their first doses.

According to the CDC, three other vaccine candidates—AstraZeneca, Janssen, and Novavax—have large-scale (Phase 3) clinical trials currently being planned or in progress.

In addition to those, international vaccine candidates have been approved for use in other countries. These include: Sputnik V in Russia, Sinopharm and Sinovac in China, and Bharat Biotech in India.

How Do The Leading Vaccines Work?


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Both Pfizer and Moderna are messenger RNA (mRNA) based vaccines–a new type of vaccine that, unlike vaccines we’ve seen in the past, does not contain weakened or inactivated virus. The mRNA vaccines “teach our cells how to make a protein—or even just a piece of a protein—that triggers an immune response inside our bodies. That immune response, which produces antibodies, is what protects us from getting infected if the real virus enters our bodies,” according to the CDC. There is no live virus, and “[t]he cell breaks down and gets rid of the mRNA soon after it is finished using the instructions.

Oxford-AstraZeneca and the Janssen vaccine (from Johnson & Johnson) are Adenovirus-based vaccines. This means that they are based on the virus’s spike protein, like the Pfizer and Moderna vaccines, but rather than mRNA, these vaccines use an inactivated cold virus to teach the immune system how to protect against COVID-19.

The Novavax vaccine is protein-based, and also focuses on the COVID-19 spike protein. In early clinical trials it produced “strikingly high levels of antibodies” and is now being tested for safety and effectiveness. The hope is that it will work like other protein-based vaccines and create memory B and T cells that will “retain information about the coronavirus for years or even decades, enabling a quick counterattack in response to a new infection.

Sinopharm, Sinovac, and Bharat Biotech are based on inactivated coronavirus, which are used to prompt an immune response. The idea of using inactivated virus in a vaccine has been around since the polio virus vaccine was developed in the 1950s.

Sputnik V, the vaccine developed in Russia, is also an adenovirus based vaccine, but differentiates itself by using a two-vector delivery into the cells.

What Should We Know About Efficacy of Each Vaccine?

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The Pfizer and Moderna vaccines have shown an efficacy rate of 95% and 94.5%, respectively, while AstraZeneca’s vaccine candidate has shown an efficacy rate in clinical trials of 70%.

Sinovac and Sinopharm have reported efficacy rates of 91.25% and 79.34%, though full results of Sinovac’s phase 3 trials will be available in January. Sputnik V reportedly has a 91.4% efficacy.

Efficacy rates for the other vaccines are not yet available.

Where And How Are The Vaccines Available?

Pfizer’s vaccine is approved in various countries, including the United States and Canada, and Pfizer expects to have 1.3 billion doses available in 2021. It’s delivered via two injections, given three weeks apart. The greatest drawback of this vaccine is with respect to storage, because the vaccine must be stored at -94 degrees Fahrenheit, which requires special refrigeration that may not be easily available.

Moderna’s vaccine has been approved in Canada, Israel, and the United States, and is similarly delivered via two injections, though given four—not three—weeks apart. The company expects to have up to 1 billion doses available in 2021. Storage is not an issue, and the vaccine can be stored in a standard medical refrigerator for up to 30 days.

AstraZeneca’s vaccine has been approved in Britain, India, and Argentina. Like Moderna, it’s a two dose vaccination given one month apart, and can be stored in “normal refrigerated conditions.” The company expects to be able to produce two billion doses of the vaccine this year.

Janssen and Novavax are still in clinical trials and have not yet been approved in any country. Important to note, however, is that unlike the other vaccines that have been either approved in the United States or have moved into Phase 3 trials in the United States, the Janssen vaccine is a single dose vaccine. Clinical trial results are expected to become available in January, and then, if the vaccine is approved, the company is hoping to produce one billion doses this year.

Sinovac is currently only available for limited use in China. Sinopharm’s vaccine has been approved in China, the United Arab Emirates, and Bahrain. Bharat Biotech’s vaccine is authorized for emergency use in India. Neither Sinovac nor Bharat Biotech have Phase 3 clinical trial data available.

It can be easy to get lost in the details about each of the vaccines–from their delivery systems to efficacy rates to all the rest. It can feel overwhelming, and easy to set your sights on one vaccine over another for largely irrational reasons (maybe that’s just me). But the thing to remember is: the vaccines are no longer just coming, they are here. They are here because of science and the global effort of the brightest minds.

Information about COVID-19 is rapidly changing, and Scary Mommy is committed to providing the most recent data in our coverage. With news being updated so frequently, some of the information in this story may have changed after publication. For this reason, we are encouraging readers to use online resources from local public health departments, the Centers for Disease Control, and the World Health Organization to remain as informed as possible.

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