Benzinga | Jun 28, 2021 10:58AM EDT

AstraZeneca COVID-19 Vaccine Shows Higher Immune Response With Longer Gap, Third Booster Dose

* A sub-analysis from the Oxford-led COV001 and COV002 trials with AstraZeneca Plc (NASDAQ:AZN) COVID-19 vaccine induced strong immune responses following a prolonged second dose interval to 45 weeks (10 months) or following a third boosting dose.

* The researchers were also able to show that a booster given more than six months after the second dose induced a strong response and increased activity against variants.

* The study found that antibodies induced after a single dose survived to some extent after one year. Still, after 180 days, the levels were half those seen at the 28-day peak.

* However, a second dose increased antibody levels between four- and 18-fold by one month after the shot.

* Thirty participants who only received a single dose in the trial were given a second one about ten months after the first.

* An additional 90 participants from those studies received the third dose in March this year.

* Higher levels of neutralizing antibodies against the alpha, beta, and delta variants of SARS-CoV-2 were also shown after a third dose than after the second one.

* Oxford and Astra have also started another trial to test a variant vaccine adapted to better protect against the beta variant. The late-stage trial is expected to recruit about 2,250 participants.

* Price Action: AZN shares are up 1.36% at $60.16 during the market session on the last check Monday.