LONDON, United Kingdom (AFP) — The effectiveness of the Pfizer-BioNTech vaccine against Covid-19 declines faster than that of the AstraZeneca jab, according to a new study published on Thursday. “Two doses of Pfizer-BioNTech have greater initial effectiveness against new COVID-19 infections, but this declines faster compared with two doses of Oxford-AstraZeneca,” researchers at Oxford University said. The study, which has not been peer reviewed, is based on the results of a survey by Britain’s […]