TAMPA, Fla. – While topline data from Johnson & Johnson shows its COVID-19 vaccine candidate is not quite as effective as formulas from Pfizer and Moderna, a virologist with the University of South Florida said the vaccine is still good news when it comes to public health.

“This is better than the flu vaccine. This is really good," said Dr. Michael Teng, an associate professor of medicine with USF's College of Medicine.

According to Johnson & Johnson, phase 3 clinical trials showed its single dose vaccine was 72% effective in the United States and 66% effective overall at preventing moderate to severe illness 28 days after vaccination. The company said it was 85% effective overall in preventing severe disease. Pfizer and Moderna have said their vaccines are around 95% effective, but Teng said the Johnson & Johnson results suggest its formula could still outperform some old standards.

"For comparison, the flu vaccine, in a good year, has a 50% to 60% efficacy," said Teng. "Some years, it's lower."

Unlike the Pfizer and Moderna vaccines, which use messenger RNA to teach the body to produce an immune response to the virus, Teng said the Johnson & Johnson candidate uses a DNA gene of a single coronavirus spike protein. That's packaged in a virus particle that's made from adenoviruses, which Teng said are common cold viruses.

“This is not an actual virus. It’s the outside shell of the virus. It’s just a delivery vehicle for that DNA gene," Teng explained.

This vaccine also doesn't require the cold storage needed for Pfizer's version. Teng said he sees it filling a void in the vaccination effort.

“The Pfizer and Moderna vaccines are expensive vaccines," he said. "They’re $20 a dose. So, that’s $40 per person. Resource rich countries, like the United States, we can afford to do that. There are a lot of countries where you can’t afford to give everyone $40 worth of vaccinations. So, in lower and middle income countries, this would be a fantastic vaccine.” 

Johnson & Johnson said it plans to apply for emergency use authorization from the FDA next month. It said doses are ready to ship as soon as it's approved.