vials of the Pfizer-BioNTech Covid-19 vaccine are prepared to be administered to front-line health care workers under an emergency use authorization at a drive up vaccination site from Renown Health in Reno, Nevada on December 17, 2020.
Patrick Fallon/AFP via Getty Images
  • Johnson & Johnson's Covid-19 vaccine was shown to be 66% effective at preventing mild and moderate infections, and 85% effective at preventing severe disease.
  • In South Africa, it proved 100% effective against preventing such severe Covid cases that the patient ended up hospitalised or dead.
  • It also has the benefits of being cheap and relatively easy to manufacture and distribute. It only requires one shot in the arm. 
  • Visit Business Insider SA's homepage for more stories.

coronavirus vaccine from Johnson & Johnson is 66% effective at preventing moderate to severe Covid-19, according to trial data. 

In its trial in South Africa, the level of protection against moderate to severe Covid-19 infection was 57%. Given that the new local 501Y.V2 variant dominates nearly all Covid cases, this means it is effective against the new variant.

The level of protection against moderate to severe infection was 72% in the United States and 66% in Latin America.

Importantly, the vaccine is 100% effective in preventing such severe Covid that the patient would end up hospitalised or dead. This was also the case in its South Africa trial. 

The Johnson & Johnson vaccine has some distinct benefits.

First and foremost: J&J's vaccine is just one shot in the arm, while both Pfizer and Moderna's are administered as two doses, given several weeks apart. Second, it can be refrigerated for months, making transportation and storage far less of a challenge. Third, it is cheaper and easier to produce. 

"Our goal all along has been to create a simple, effective solution for the largest number of people possible, and to have maximum impact to help end the pandemic," Johnson & Johnson Chief Executive Officer Alex Gorsky said in a statement when his company's results were released. 

During a recent call at the US National Institutes of Health, Anthony Fauci, the US' top infectious disease expert, stressed the importance of adding "yet another platform, another candidate into the mix in our global efforts against this extraordinary pandemic."

See also | Covid-19: J&J's single-dose coronavirus vaccine 57% effective against SA variant

"This has really important domestic and global public health implications," Fauci said of the J&J vaccine, noting that "it is one shot," that doesn't need to be stored at super-chilled temperatures, and it is relatively inexpensive.

Below are the basics of how these three Covid-19 shots compare, based on what we know so far.

The information on J&J's vaccine comes from a press release, while data on Moderna and Pfizer's shots is based on what the companies submitted to the US Food and Drug Administration for emergency use authorisation. J&J said it plans to submit its data to the FDA next week to request an EUA, which would green-light the vaccine for use in adults across the US.

How well the shots prevent illnesses

Moderna: 94.1% effective at preventing symptomatic infections, 100% effective at preventing severe infections, after two doses.

Pfizer: 95% effective at preventing symptomatic infections, nearly 100% effective at preventing severe infections (only one case among more than 18,000 vaccinated individuals in the trials), after two doses.

Johnson & Johnson: 66% effective at preventing moderate to severe infections, 85% effective at preventing severe infections, after a single dose.

Note: A J&J executive said its shot may have shown a lower level of efficacy because it was tested at a time when higher levels of the virus, including variants that may evade vaccines, were circulating.

Bruno Cassaro de Andrade, a chemical engineering student, works with a test separating specific proteins to be applied in the production of coronavirus vaccines on March 24, 2020 in Belo Horizonte, Brazil.
Pedro Vilela/Getty Images

How many people tried them out

Moderna: trials included more than 30,000 volunteers across the US.

Pfizer: trials included more than 43,000 volunteers across six countries: the US, Argentina, Brazil, Turkey, Germany, and South Africa.

Johnson & Johnson: trials included more than 43,000 volunteers across eight countries: the US, Argentina, Brazil, Chile, Colombia, Mexico, Peru, and South Africa. 

About half of the volunteers in each company's study got real shots, and half got placebo jab. 

How they work

Moderna: mRNA.

Pfizer: mRNA.

Johnson & Johnson: adenovrius.

How you take them:

Moderna: two shots in the arm, given 28 days apart.

Pfizer: two shots in the arm, given 21 days apart.

Johnson & Johnson: one shot in the arm.

A nurse at the Royal Cornwall Hospital prepares to administer a COVID-19 vaccine in Truro, United Kingdom.
Hugh Hastings/Getty Images

How long it takes for protection to kick in:

Moderna: some protection from infection begins 10-14 days after first shot, with full protection achieved two weeks after the second shot.

Pfizer: some protection from infection begins 10-14 days after first shot, with full protection achieved one week after the second shot. 

Johnson & Johnson: some protection from infection begins as early as 14 days after the shot, with full protection measured 28 days after the jab. That protection may get even better as time goes on, though, as zero Covid-19 cases were reported in patients who'd been vaccinated for 49 days or more. 

How long hospitals and clinics can store it in the fridge 

Moderna: 30 days.

Pfizer: 5 days.

Johnson & Johnson: 3 months.

"The company can actually produce, in a reasonable period of time, billions of doses," Fauci added, suggesting that though this vaccine may not be as potent as the mRNA vaccines from Pfizer and Moderna, it could become a more widespread tool to help suppress the pandemic.

Additional reporting by Business Insider SA.

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