It can be quite easy, reading the press, to believe that the pandemic will never end. Even when good news about vaccines started to arrive in the autumn, this grim narrative managed to harden. In the past month, you could read “five reasons that herd immunity is probably impossible”, even with mass vaccination; breathless reports about yet-uncharacterised but potentially ruinous variants, such as the “double mutant” variant in India, or two concerning variants potentially swapping mutations and teaming up in a “nightmare scenario” in California; get ready, some analysts said, for the “permanent pandemic”.

Among many people I know, a sort of low-grade doom has set in. They think the vaccines are a mere sliver of hope, only holding back the virus for a short time before being worn down by a rush of ever-cleverer variants that will slosh around us, perhaps for ever. Things might briefly get better, they believe, but only by a little, and even that is tenuous.

However despite such dark talk, and the potential difficulties along the way of vaccine rollout, I still remain optimistic. Since about the midway point of last year I have believed that extremely potent vaccines are going to end the pandemic. They’ll do so by either driving the disease down to near-extinction, or so constraining its force and spread that it becomes a manageable concern, like measles or mumps. I actually think this will happen fairly soon, as long as we get everyone – the whole world, not just the rich – vaccinated.

The scientific case for optimism is straightforward. The vaccines we have are beyond very good, they’re among the most effective ever created. They appear to be potent in real-life situations, and results so far show that protection is long-lasting. Crucially, new results in the US show that the mRNA vaccines used there effectively prevented coronavirus infections – not just serious symptoms – in results similar to those previously reported by a UK-based study. And another study in the UK suggested that vaccinated groups were less likely to spread coronavirus infection overall. This is exactly what we need to choke out the pandemic: vaccines that don’t just protect, but actually halt the virus infecting people and spreading.

When it comes to variants, it is clear that some are more infectious, and some are more deadly. But their interaction with vaccines isn’t yet clear. Some lab-based results show that certain viral mutations may make some immune responses less potent. And one study suggested the Oxford/AstraZeneca vaccine might be less potent against the South African variant. But the majority of scientists believe that vaccines have so far held the line, and will continue to do so. If variants continue to make small advances, vaccines can be updated. A doomsday strain may be possible, but exceedingly hard to predict. Evolution isn’t an on-demand miracle worker for viral supremacy; even over decades most viruses don’t escape vaccine protection.

The stories suggesting a dismal and dangerous future aren’t wrong, per se. There is clearly a long way to go in ending the pandemic. A few pieces are sensationalistic (some scientists have taken to calling the rolling panics accompanying each new mutation “scariants” or “mutant porn”), but most are good-faith reporting of what experts say, or attempts to tune public discourse away from naive false hopes (most articles) or, more rarely, away from miserable and abject doom (this article).

What they do, in aggregate, is try to describe the future in a time of incredible uncertainty. And, as a rule, we’re quite bad at dealing with uncertainty. During the pandemic the public sphere sometimes appears to be in the middle of a full-blown epistemic crisis over this, with wildly different claims about what “the science” portends. The truth is that the science we see now is itself uncertain. It’s not a process of years-long studies that provide near-definitive answers. We’re all mucking about behind the scientific curtain, looking at science as it’s being done; at inferences and hypotheses; incomplete and ongoing studies. Often, what is parsed publicly these days as “science” is just informed guesses by experts.

This can pile up and become paralysing. Especially since the pandemic itself exploded our horizon for negative possibilities. It seems like each day there there are a thousand new paths the future might take, and no way to know how solid each might actually be. Even more, as each piece of good news comes freighted with new caveats and doomsday scenarios, it can feel like things are nearly as uncertain now as they were at the beginning of the crisis. Like everything we know could suddenly and radically shift, the same way it did last March.

That isn’t the case. There are two massive and opposing fronts of uncertainty facing us. We don’t yet know for certain if vaccines will effectively halt transmission. On this, we have some indication that it looks good, and conclusive answers are coming. And we don’t know what (terrible) variants might yet emerge. But even though that unknown seems massive, variants aren’t some immunological antimatter destined to suddenly and totally vaporise the vaccines.

Seen this way, the possibilities don’t look so grim. Early in the pandemic we had nothing, the timeline for vaccines and whether they would work was uncertain, the outside chance was that they would take years, or they would fail. The horizon was the virus, and just how bad it could get. Now the vaccines are the horizon, and it is the virus that has only the outside chance to delay or disrupt our path there.