NEW YORK (CBSNewYork) — There is some potentially very good news about how long immunity will last after getting the Pfizer or Moderna COVID-19 vaccines.

A new study suggests that immunity may last for years, without booster shots.

But as CBS2’s Dr. Max Gomez reported Monday, that will depends on how the coronavirus evolves.

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They are the two critical questions about the COVID vaccines. Will the current shots protect against variants and will we need booster shots to provide long-lasting immunity?

“For the South African variant, we had 100% efficacy. For the U.K. variant that was predominant in Israel, for example, or in the U.K., we had 97% efficacy. So, the current vaccine protects. The question is for how long,” said Dr. Albert Bourla, CEO of Pfizer.

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That question was still up in the air when Gomez interviewed Bourla for the CURA Foundation’s Vatican Conference last month.

Now, a new study in the journal Nature suggests that people immunized with the MRNA vaccines, those made by Pfizer and Moderna, may not need boosters, as long as the coronavirus doesn’t mutate too far from its present forms.

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Bourla was cautious, predicting six to 12 months of immunity, but this new study finds that the MRNA vaccines not only induce so-called “memory cells” that last at least a year, it also found that the vaccine forms sites in lymph nodes that produce long-lived immune cells that can recognize and remember a broader range of coronavirus mutations.

“But as I said, to avoid any surprises, because you never know before you have the data, we are currently testing boosters for the same vaccine, and we are currently testing boosters with a tailor made vaccine,” Bourla said.

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The study only applies to the Pfizer and Moderna MRNA vaccines, not the Johnson & Johnson vaccine. And there are some people who may still need boosters — older adults and people with weak or drug-suppressed immune systems. Of course, if the virus mutates a lot, boosters for the new strains may still be needed.

Dr. Max Gomez