Over the past two weeks, there has been a daily deluge of news — and frustration — about COVID-19 vaccinations, headlined this week by the establishment of mass-vaccination sites in the South Bay, East Bay and San Francisco. Providers have also been expanding access to those at most risk of severe illness or death.

The initiatives should be good news for those confounded by the twisted explanations, balky websites, and hours-long hold times that have characterized the vaccine rollout to date. But the biggest problem remains: the limited supply of approved vaccines, even as the Biden administration ramps up production and a new one-shot vaccine appears to be nearing readiness for distribution.

Here’s a look at the latest developments, and what they mean to you.

So who can get the vaccine right now?

The state has authorized the vaccination of front-line healthcare workers, nursing home patients and, more recently, people ages 65 and older. But not every county and healthcare provider has been able to accommodate those groups, and the state concedes these residents will be prioritized “as supplies allow.”

Contra Costa, San Mateo, Santa Clara and San Francisco counties have formally green-lit vaccinations for residents older than 65. Alameda County says that coverage for seniors will begin Monday, though some hospital systems have already started.

But others are choosing to limit distribution because of inadequate supply. Kaiser, for instance, is restricting vaccinations for non-healthcare workers to patients 75 and older, citing limited doses. John Muir Health says it plans to expand to patients ages 65 to 74 on Feb. 15.

Bay Area counties are still urging eligible vaccine recipients to go to their own healthcare providers first, to ensure efficient use of each entity’s vaccine allocations and reserve the doses provided to county health systems for uninsured people and underserved communities.

But the messaging has shifted in the past week. Santa Clara County has just instituted a “no wrong door” policy encouraging anyone currently eligible for a vaccine to get one from any provider, regardless of hospital membership or insurance. That comes after a revelation that some 20% of county-allotted vaccines were going unscheduled. Other counties are now offering similar guidance.

Meanwhile, interest groups continue to advocate special vaccine priority for their members, including farmworkers, teachers, and those with health conditions. Last week, a group of Bay Area health officers called on providers to resist those pleas. Just focus on the elderly, they said.

How are these mass-vaccination sites going to work?

This week, a state-federal partnership was announced that will task the Federal Emergency Management Agency with operating a mass-vaccination site on the grounds of the Oakland Coliseum beginning Feb. 16; reservations are promised through the state’s new MyTurn.ca.gov website. The Moscone Center has just opened as a mass-vaccination site run by San Francisco and Kaiser. Santa Clara County announced that it is partnering with the San Francisco 49ers to put up such a site at Levi’s Stadium in Santa Clara, opening Tuesday; check sccfreevax.org for appointments.

The purpose of these sites is to expand the reach of the vaccine to targeted populations and provide some relief to people who are uninsured or can’t get through scheduling systems of their own providers. Some of these organizations are also putting pop-up sites in heavily-impacted neighborhoods to the same end.

What’s happening with supply? Isn’t a new vaccine supposed to be coming out soon?

A significant increase of doses is needed to vaccinate enough of the U.S. population to achieve herd immunity and end the pandemic. Even with the state tripling its daily vaccinations to 150,000 over the past month, just 9% of California’s 40 million residents have gotten vaccines.

The Biden administration has ordered 200 million more doses from Pfizer and Moderna, and plans to send 1 million doses to pharmacies across the country. CVS will begin administering vaccines at 100 of its California stores starting Thursday.

The supply situation stands to improve with the distribution of a new Johnson & Johnson vaccine, after it is reviewed for emergency authorization by the Food and Drug Administration at the end of the month.

Dr. Monica Gandhi, a professor and infectious-disease expert at UC San Francisco, is optimistic about the impact of the Johnson & Johnson vaccine, since it requires just one dose — the Pfizer and Moderna vaccines consist of two shots administered between three and four weeks apart — and it doesn’t require frozen storage.

The company says it can supply 100 million vaccine doses to the federal government in the first half of 2021.

“This is a game changer,” Gandhi said. “The vaccine rollout is going to be way faster.”

As supplies increase, more categories of people will be allowed to be vaccinated. If vaccine production continues to increase as planned, people 16 and older in the lowest-risk categories could get start getting vaccines by this summer.

Let’s go back to those second doses. I’ve heard about side effects. How bad are they?

Reports in recent days have noted that second doses of the Pfizer and Moderna vaccines are producing more side effects than the first dose — primarily flu-like symptoms such as swelling, pain, body aches, headache and fever. But medical experts say that’s a sign that the vaccine is triggering the desired immune response.

Gandhi said in most cases, the second-dose swoon is manageable with pain relievers and rest.

I’m fully vaccinated. What am I allowed to do?

Mainstream medical consensus urges vaccinated people to conduct themselves as they would if they weren’t vaccinated, because they could still be carriers — research has not yet established that the Pfizer and Moderna vaccines prevent transmission of the disease.

But Gandhi sees little risk in two vaccinated people meeting and having contact. And she believes a vaccinated person who has tested negative also has little to fear in interacting with unvaccinated friends and family as well. Just take appropriate precautions: Mask up, and try to maintain your distance.

“This is a question of messaging that tells people that even if you’re not vaccinated, nothing changes. I know public-health officials are well meaning, but that’s not how the real world works,” Gandhi said. “I don’t think that’s tenable, people have been waiting so long for the vaccines, and loneliness is profound.”