CORONAVIRUS/AZ-Moderna vaccine mix effective against Delta: NTUH study

A study on COVID-19 vaccines by National Taiwan University Hospital (NTUH) has found that mixing the AstraZeneca (AZ) and Moderna jabs offered better protection against the Delta variant of the disease than two doses of the AstraZeneca vaccine.

The two-jab mix gave a better immunoglobulin G (IgG) antibody response and a higher level of neutralizing antibodies against the Delta variant of COVID-19 than two AZ jabs, NTUH Department of Medical Education director Sheng Wang-huei (???) said at a press event.

According to NTUH, 400 people were involved in the trial from June to August this year, with blood samples taken 14 and 28 days after the second jab.

Research participants were divided into four groups - those who got two AstraZeneca jabs eight weeks apart; those who got AstraZeneca + Moderna doses eight weeks apart; those who got AstraZeneca + Moderna doses four weeks apart; and those who got two Moderna doses four weeks apart.

They were aged between 20 and 65, and 75 percent were female, the university hospital said.

On the IgG antibodies, Sheng said those who got two shots of the AstraZeneca vaccine eight weeks apart had an IgG level that barely reached 500 binding antibody units per milliliter (BAU/mL) after 14 days.

Recipients of the AstraZeneca/Moderna combo had IgG antibodies exceeding 2,500 BAU/mL, and those who got two Moderna jabs taken four weeks apart had IgG antibodies exceeding 4,000 BAU/mL after 14 days.

In terms of virus neutralizing antibodies, the number was less than 50 international units per milliliter (IU/mL) in participants who had two AstraZeneca doses eight weeks apart after 14 or 28 days, the study found.

That increased to 300 IU/mL after 14 days for the AstraZeneca/Moderna jabs taken eight weeks apart.

The results indicated that vaccine mixing can be more effective against either the Alpha or Delta variants of COVID-19 than simply two AstraZeneca doses, Sheng said.

CECC official Lo Yi-chun (???) urged those who have received two doses of the AstraZeneca vaccine not to be concerned about their level of antibodies based on the results.

He said the NTUH study was based on an interval of only eight weeks between AstraZeneca doses, while overseas studies have shown that the longer the interval between AZ doses, the better the antibody level and protection.

Separately during a daily press briefing on Friday, the CECC said the mix-and-match vaccine program that begins Saturday will run until Nov. 24, rather than Sunday as had originally been planned.

The CECC said 180,000 people made appointments to get their second COVID-19 jab using the mix-and-match approach by the appointment deadline at 4 p.m. on Friday.

Also on Friday, Taiwan took delivery of another batch of the AstraZeneca COVID-19 vaccines, consisting of 676,000 doses.

The shipment arrived at Taoyuan International Airport via China Airlines flight 834 at 3:23 p.m.

The expiration date on this batch of doses is March 31, 2022, the CECC said, adding that with the latest shipment, Taiwan has received roughly 7.8 million of the AstraZeneca vaccine doses it has ordered to date.

Source: Focus Taiwan News Channel