The pandemic prognostications of the last months have been whiplash-inducing. First, reports warned that we would never attain herd immunity, and the country convulsed in anxiety in response. Then, suddenly, the Centers for Disease Control and Prevention told us it was safe to remove masks — first outside, and then in short order inside, too, provided you’re fully vaccinated. Is this how the pandemic ends, not with a bang but an imperfectly deployed set of talking points?

Almost. For most vaccinated people, yes, the pandemic is vastly less threatening — but there are enough people out there who aren’t yet vaccinated but would like to be that we can’t discard all precautions yet.

The United States has not managed a perfect vaccination rollout, but in many places it can certainly count as good enough, at least for now. You can see this in the Northeast, which has some of the higher per capita mortality rates from the coronavirus in the country and, indeed, the world. In New Jersey, more than 1 in every 350 people died of the virus. And yet until quite recently, it was transmitting regardless. There was even a little bump in cases as the variant first detected in the U.K., also known as the alpha variant, rolled into town in March.

There wasn’t a corresponding bump in deaths — in New Jersey or elsewhere nearby. This has to be counted as a good thing and suggests that we are finally managing to decouple cases from the carnage they wreak down the line. This is awesome. It is a mammoth achievement. It’s gotten even better than that, both regionally and nationwide: Case counts are as low or lower than at any time in a year, and hospitalizations and deaths are down, too. The second pandemic summer in the United States is set to be enormously better than the first.

At last there are reasons for optimism that even epidemiologists can agree with, yet the emergence of the variant first detected in India, also known as the delta variant, is a serious cloud on the horizon — especially for the 35 percent of over 18-year-olds in the United States who are yet to receive any vaccine dose at all.

Delta is thought to be responsible in large part for the dreadful recent surge in India, where deaths appeared to peak at over 4,000 recorded every day — which is almost certainly a huge underestimate. Just this week, India has reported more than 6,000 deaths in a single day, catching up with some of the previous underreporting. The sheer magnitude of the crisis there made it hard to collect data, but multiple introductions of the delta variant to Great Britain (where the pandemic has recently been very quiet indeed) have allowed epidemiologists to study it.

Delta is bad; even if we don’t know exactly how bad, recent work has pegged it at maybe 40 percent more transmissible than the variant we’ve been dealing with until recently (itself more transmissible than the first wave of virus from the spring of 2020). Early data suggest that delta is also more likely to lead to hospitalization, meaning it is more severe. To make matters worse, delta seems to be slightly more able to evade immunity from vaccines, and it is already making up about 6 percent of newly diagnosed cases in the United States.

Still, it’s cause for concern, not panic: Two doses of the vaccine seem to provide good, if not perfect, protection against the delta variant. Just as important, if not more so, it seems that the breakthrough cases are mild. However, those who are not vaccinated remain vulnerable to infection, and when it comes to delta, that means a virus that appears more dangerous than its predecessors. And in some parts of the country, a large fraction of the population has yet to receive any vaccine at all. There are a lot of reasons for this, but vaccine access deserves more attention than hesitancy. Imagine wanting to get the shot, but not being able to because you couldn’t get time off work to take it or to recover from any side effects? And imagine knowing the same thing was true for your colleagues.

This is why we should not dispense with some of the other things we have been doing to stand in the way of the virus just yet, even though vaccination rates remain high and case rates are dropping. Even though I am fully vaccinated and as a result very unlikely to get infected and transmit, I still don’t want to be the weak link in the chain that lets the virus into that parallel unvaccinated network around me. So I’m going to keep doing those easy things to limit the chance I get infected: meeting people outside if possible, limiting contacts and wearing a mask indoors whenever I’m in a crowded public space with lots of people whose vaccination status I don’t know.

The future is brighter than at any stage in the past year, but we can make it brighter still by holding the virus back a while longer while we get vaccination rates as high as possible. Every dose matters, and that is even more true in the face of delta and whatever comes next. We can expect to face more variants as the summer turns to fall and winter. But we can also do more than just watch the pandemic in the rearview mirror — if we keep at it a bit longer, we can leave it in the dust and then turn to vaccinating the rest of the world.