Johnson & Johnson (JNJ), which just became the latest company to get its COVID-19 vaccine emergency use authorization from the Food & Drug Administration (FDA), is facing some questions about the single shot's efficacy.

The uncertainty stems from the JNJ inoculation's overall efficacy rate of 66%, which compares less favorably to Pfizer (PFE)’s 95% and Moderna (MRNA)’s 94%. However, public health experts have dismissed those concerns and stressed the importance of the J&J vaccine, with doctors urging the public to consider the big picture.

“The way I judge the vaccines is on what matters: Their ability to prevent hospitalization, death, and serious illness,” Dr. Amesh Adalja, senior scholar at John Hopkins Center for Health Security, told Yahoo Finance Live in an interview.

“All three do that tremendously well, no qualms about the efficacy. They are the path to ending the pandemic and stopping the damage that this virus is doing," Adalja added.

Though J&J’s vaccine is less effective at preventing someone from catching COVID, it’s actually 85% effective at preventing serious cases and hospitalizations — and 100% effective at preventing death.

“I would not hesitate to get the Johnson & Johnson vaccine if available to you,” Adalja said. “I would focus on what we want the vaccines to do: Prevent serious illness, and all of them are off-the-scales good when it comes to that.”

The J&J vaccine differs from Pfizer and Moderna’s in that it’s only one dose and does not need to be in cold storage, making it easier to be distributed across the world.

“The path through is going to be getting a vaccine,” Adalja said. “These vaccines all do that really well … One dose of the vaccine and you’re likely done and you have that protection against serious illness. That’s what we want to do and I think that’s what we have to go back to is telling people we’re not going to COVID zero. We’re not getting rid of this or eradicating this virus. We’re basically making it a much more manageable problem than it’s been throughout the pandemic.”

'Lots of reasons to be optimistic'

However, Adalja encouraged optimism about the vaccines, as he emphasized that the more available, the better.

“We will get immediate benefits the more people we vaccinate,” Adalja said. “We’re already seeing that in Israel, we’re already seeing that with nursing home populations. I think the goal now is just to make this all-out effort, where no holds are barred, and people are just getting vaccines into their arms in an assembly-line process.”

The vaccine news and recent decline in cases and hospitalizations have prompted some states to loosen their restrictions. The latest to do so was Texas, which on Tuesday fully lifted its mask requirements and allowed businesses to open at 100% capacity.

Yet Adalja urged caution, with the U.S. yet to reach herd immunity, which is estimated to be between 75-80% of the population.

“Once we get our vulnerable populations vaccinated — right now, I think about 40% of those aged 65 and above have been vaccinated,” Adalja said. “Then you’re going to be less worried about spread because everybody that could get hospitalized is protected through the vaccine. That’s when I think you’ll see some of those mask mandates lift.”

Still, “some people may wear masks longer because they’ve gotten accustomed to them, maybe on public transit or in crowded places," the physician explained.

"The masks are going to be there until hospital capacity is never a concern, meaning we’ve gotten everybody who has the threat of being hospitalized, at least the majority of those, vaccinated. That’s likely going to be in the summer," he added.

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), initially predicted that vaccines would be available to the general public by April, but later amended that timeline to late spring or early summer of 2021. Still, it's a step in the right direction.

“Remember: Just wearing a mask is not that big of a deal compared to all the other activities that’ll start to open up as we get our vulnerable populations vaccinated, and we’re starting to see that,” Adalja said. “There are lots of reasons to be optimistic about this vaccine. It’s a path forward to ending this pandemic and getting our lives back.”

Though the virus is likely not to be eradicated any time soon, that doesn’t mean it can’t be contained and controlled, much like the flu virus that makes its way throughout the country every year or even the common cold (which is caused by a coronavirus).

“What we need to do is really go back to first principles,” Adalja said. “Why did COVID-19 even rise to our attention? It rose to our attention not because it caused mild illness but serious illness, hospitalizations, and death. That’s why a whole vaccine program was embarked upon to stop the virus from doing that, to basically tame it or defang it with the vaccine, to make it more like our ordinary respiratory viruses or like the other coronaviruses that cause 25% of our common colds.”

J&J’s vaccine, along with Moderna’s, Pfizer’s, and international companies AstraZeneca’s and Novavax’s, have data to show they can do that.

“Whatever path you get to ... it doesn’t matter because our goal in the end is to make this a tamed virus, one that’s no longer a public health emergency, one that will never strain hospital capacity,” Adalja said. “That’s our overarching societal goal.”

Adriana is a reporter and editor covering politics and health care policy for Yahoo Finance. Follow her on Twitter @adrianambells.

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