COVID-19 vaccines remain effective, but AstraZeneca's wanes faster than Pfizer's, suggest UK data

Protection against COVID-19 wanes faster for people who have had two doses of AstraZeneca's vaccine than for those who had Pfizer's jab, according to newly released figures.

Public Health England's study on the duration of protection from COVID-19 vaccines was published on Tuesday.

It came as UK Prime Minister Boris Johnson announced a mass booster program for the over-50s using the Pfizer or Moderna jabs, rather than the AstraZeneca vaccine.

Many people aged over 40 in the UK received the Oxford University-developed AstraZeneca vaccine, leading to questions about why it was not being included in the booster program.

According to the study, 20 weeks after a second dose, the effectiveness of the AstraZeneca shot in stopping symptomatic COVID-19 falls, for Delta variant cases, from nearly 70 percent to 50 percent.

(CGTN)