A little knowledge can be a dangerous thing, all the more so when the facts behind that “knowledge” are not clearly understood.

This is nowhere more true than in the case of the COVID-19 vaccines that, in miraculously short order, have been developed for the war against the potentially fatal disease that arose in the year-long coronavirus pandemic.

On Saturday there was more good news: A third vaccine, created by Johnson &Johnson, has been added to the public health munitions, along with the earlier arrivals from the Pfizer and Moderna groups. This could be the game-changer needed to move America closer to the “herd immunity” needed for recovery — ahead of the viral mutations that have unsettled the battle.

The crisis has been so devastating that people have devoured what information they got on the vaccines. These will be the most powerful tool in defeating the virus and, fortunately, most in Hawaii are champing at the bit to get their shots.

The problem is that the way the drugs have been rolled out, with widely reported percentages of efficacy, has convinced some people that one is better than another. In fact, one may be better suited to one person over another, but all of them will combine to stabilize public health. That’s what’s so critical now.

Guidance from the federal Centers for Disease Control and Prevention will help the state decide the best way to deploy the 67,280 doses anticipated this week. This includes 11,900 Johnson &Johnson doses, which can be delivered in one shot and stored in regular refrigerators. The cold and ultra-cold requirements of Moderna and Pfizer, which each requires two shots, have complicated distribution somewhat.

But their advantage? These new-technology “mRNA” vaccines emerged from testing with astonishing, well-publicized efficacy rates approaching 95%. Johnson &Johnson’s entry, approved for emergency use by the Food and Drug Administration, has a global efficacy rate of 66%.

Tempting as it is to take these figures at face value, the percentages do not provide a complete picture. More public messaging about how much all contribute to public safety will be crucial.

The Johnson &Johnson formulation, for example, was tested after the variants of the virus emerged, whereas the earlier vaccines weren’t. There’s a fair degree of uncertainty, then, around how the efficacy rates compare in the current progress of the disease.

And for people for whom returning for a second dose is a problem, either because of job constraints or transportation challenges, they would be safer to receive the newest vaccine, if it becomes more readily available to them.

People who are younger and healthy might find it especially advantageous to take the one-shot option, said Lt. Gov. Josh Green, who as a medical doctor has taken a lead role in the implementation of the state’s vaccine program.

Green, speaking Monday on the Honolulu Star-Advertiser’s “Spotlight Hawaii” webcast, added, though, that Hawaii residents will be able to choose for themselves.

“No one should have to take one vaccine over another,” he said, and the personal choice aspect is undeniable.

But the bottom line is that it will take a more collective mindset on the vaccine mission to yield a collective gain in public health. The longer the virus is allowed to circulate among those without immunity, the more challenging it becomes to lock it down.

This means that achieving “herd immunity,” once spoken about in terms of 70% being vaccinated, may take more than 80%. Hawaii life won’t approach normalcy until the emphasis moves toward getting us there, and away from which vaccine is “best.” They’re all good.