Even with vaccination efforts in full power, the theoretical threshold for vanquishing COVID-19 looks out of reach, say scientists who’re modelling the pandemic’s progress. Most estimates had positioned the brink at 60–70% of the inhabitants, however a number of components appear to be pushing it up:

• Authorized vaccines can stop individuals from getting sick with COVID-19. But it’s nonetheless unclear to what extent they block an infection and transmission. If vaccines don’t stop SARS-CoV-2 from spreading, then many extra individuals have to be vaccinated to attain herd immunity.

• A wonderfully coordinated international vaccination marketing campaign might need worn out COVID-19, however the roll-out is wildly uneven. For instance, Israel is closing in on the theoretical herd-immunity threshold, however its neighbours Lebanon, Syria, Jordan and Egypt have but to vaccinate even 1% of their respective populations. This leaves pockets of vulnerability the place the illness can surge after which unfold.

• There are not any approved vaccines for kids, so most adults would have to be immunized to attain herd immunity.

• We’re in a race with new variants of SARS-CoV-2 that is likely to be extra transmissible and proof against vaccines. A brand new variant may undo our progress.

• It’s not but clear how lengthy naturally acquired immunity to SARS-CoV-2 an infection lasts, however it’s most likely not without end. As immunity wanes, individuals turn into prone to reinfection and not contribute to herd immunity.

• The herd-immunity threshold will get increased when individuals loosen up their vigilance. “The vaccine is not bulletproof,” says biomedical information scientist Dvir Aran. Imagine {that a} vaccine provides 90% safety: “If before the vaccine you met at most one person, and now with vaccines you meet 10 people, you’re back to square one.”

So what does the longer term seem like with out herd immunity? The spectacularly speedy improvement of vaccines that cut back hospitalizations and deaths nonetheless implies a hopeful end result. But in the long run, scientists suppose COVID-19 may turn into an endemic disease, very similar to influenza.

Nature | 10 min read

Read extra: The coronavirus is here to stay — here’s what that means (Nature | 11 min learn)

As immunologists pivoted to deal with the rise of COVID-19, they produced extraordinary leaps in our understanding of the immune response to SARS-CoV-2. Nature Reviews Immunology steps through a timeline of key discoveries and highlights areas for future investigations.

Nature Reviews Immunology | 40 min read

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The variety of international locations the place nobody has but been vaccinated, in keeping with The New York Times’s overview of the extreme variations in who can get the jab in several places. (5 min learn)