Johnson & Johnson COVID-19 vaccine has been found 66% effective, which is quite low compared to the figures shown by Pfizer (95%) and Moderna (94.5%).

Unlike Pfizer and Moderna’s vaccine, Johnson & Johnson’s vaccine is a one-dose shot, which has not been approved yet. However, the company has submitted the Emergency Use Authorization (EUA) to the FDA.

Dr. Aruna Subramanian, Infectious Disease Physician at Stanford, said the Johnson & Johnson vaccine is considered effective because of how well it prevents severe cases of COVID-19, according to POPSUGAR.

Clinical trials have shown that the Johnson & Johnson vaccine is 85% effective in preventing severe illness and 100% effective at preventing hospitalization and death from COVID-19.

Dr. Subramanian told POPSUGAR, “It’s when you expand the data to include mild and moderate cases of COVID-19 that the effectiveness numbers drop. That’s normal because based on the evidence we have now, we don’t know that any of the vaccines actually stop you from being infected; they just stop you from developing severe symptoms after infection.”

“Essentially, you can still breathe in viral particles,” she explained, and they will still replicate to some degree in your body.

“But with an extra boost from the vaccine, your immune system keeps it in check so that your symptoms might just be mild,” Dr. Subramanian added. “You may not have as much virus, and it’ll get rid of it before your symptoms get too bad.”

However, Dr. Subramanian warned against comparing vaccine efficacy rates head-to-head.

“One reason is because the Johnson & Johnson and AstraZeneca vaccines were tested in areas with new SARS-COV-2 mutations; both ran trials in South Africa, where the B.1.351 strain emerged, and AstraZeneca additionally tested in the UK, where the B.1.1.7 variant was found,” according to POPSUGAR.

 Overall, Dr. Subramanian said, “Everybody should be reassured that all of these vaccines that are getting approved are highly, highly effective in preventing hospitalization, death, and even severe disease.”

“People shouldn’t get too hung up on which vaccine they’re receiving,” she added. If you’re eligible to get a vaccine, take her advice, “go ahead and get it, because all of the vaccines are going to get us closer to herd immunity,” advised POPSUGAR. Meanwhile, make sure you follow the CDC’s guidelines to stop the spread of the virus by practicing social distancing, washing your hands often, and wearing a facemask in public.