Waning immunity poses coronavirus vax challenge

To be effective a vaccine would need to generate a stronger response or be given regularly, researchers suggest

Emerging evidence that immunity against COVID-19 may be short-lived poses challenges for an effective vaccine, researchers say with some suggesting regular boosters could be required.

Preliminary studies in China, Germany, UK and elsewhere have found that patients infected with SARS-CoV-2 make antibodies, but they appear to last only a few months.

That raises big problems for developers of potential COVID-19 vaccines, experts say — and for public health authorities seeking to deploy them to