The public-health authorities at the U.S. Centers for Disease Control and Prevention clearly had multiple reasons for updating their guidance on what COVID-vaccinated Americans can do safely as the nation strives to reach “herd immunity” and resume a more normal way of life.

One certainly was relaying some good news. The CDC announced on Tuesday that being fully vaccinated means a relaxation of restrictions, especially while outdoors, that have pushed people into a degree of social isolation they fervently want to end. Lockdown has been unkind in innumerable ways.

Fully vaccinated grandparents and their grandkids — one household at a time — can reunite safely without masks, for example. And there’s no reason for those who’ve completed their COVID-19 shots to wear masks outdoors, the agency concluded, unless they’re in a crowd of strangers who may or may not be immunized. Additional incremental steps toward freedom are listed by the CDC (808ne.ws/CDCguidance).

Importantly, the experts also are making it clear that taking the vaccine enables people to have these benefits without endangering others — in the hope that the positive outcome will convince more of the vaccine-hesitant to get in line for their shots, too.

This persuasion will be essential, here and nationwide, to boost the population into the herd-immunity range, with 70-85% having some protection from the disease. That’s when the longed-for “new normal” can start in earnest.

There’s ample cause for confusion in all of this, though. The public needs clearer direction from the governor and especially the county mayors on how to interpret the federal guidelines.

Those updates should allow for a measured expansion of freedoms — with a cautionary note. Hawaii has come too far to toss all protocols aside, not when the end game may be merely a few months away.

The CDC advisory includes a helpful chart (808ne.ws/masks) outlining what the vaccinated and unvaccinated could do and at what risk, with no masks in just a handful of cases and masking up in most other circumstances.

But it does not define, for example, what constitutes a “small outdoor gathering with fully vaccinated and unvaccinated people.” In that scenario, the unvaccinated are urged to wear a mask while the vaccinated participants can do without, according to the CDC.

In Oahu’s case, this raises the question of outdoor youth sports, which Mayor Rick Blangiardi has allowed to make a limited return: players but no fans. Families of the young athletes have pressed for reconsideration, given that it is an activity in an open-air setting, not unlike a beach outing that groups up to 10 can enjoy together.

It may indeed be time for Blangiardi to make this possible, but only if spectator families at the parks gather just within their small households. It’s the large-scale congregating that must be avoided, at the direction of the mayor and with the cooperation of the athletic organization leaders. This would not be a sanctioned return to pre-pandemic potlucks.

Broadly, this is not yet the time to expand the size of social gatherings in general. Outdoors or not, the untethered music events or mass parties that have sprung up in the past should be barred.

That said, the expanding percentage of COVID-immunized people should in the near future anticipate attending larger events, when showing their vaccine credentials may admit them to venues. The CDC guidance does seem to lay the groundwork for that public-health privilege.

For the present, isle residents should be heartened by the new eased guidance on outdoor activities. With local authorities filling in some of the blanks, signposts show the vaccine is leading Hawaii in the right, healthy direction.