Data suggest most UK adults had antibodies after one dose of AstraZeneca or Pfizer COVID-19 vaccine
A study preprint (n=8,517, not yet peer reviewed) found 96.42% had antibody levels 28 days after a single dose, rising to 99.08% within 14 days of the second dose. After the first dose, antibody levels were lower in older people and in those on immunosuppressive therapy.
Source:
British Medical Journal
SPS commentary:
Disparities did not persist after a second dose, with high antibody titres observed for nearly all people across all ages, demographics, and clinical groups.
Authors highlight observed disparities in antibody levels after the first dose by age and comorbidities highlight the importance of ongoing non-pharmaceutical preventative measures such as social distancing, for partially vaccinated adults, particularly those who are older and more clinically vulnerable.