S.Korea to mix-and-match COVID-19 vaccines

Sangmi ChaAAP
Shipment delays and strong uptake means South Korea has used up its available AstraZeneca reserves.
Camera IconShipment delays and strong uptake means South Korea has used up its available AstraZeneca reserves. Credit: EPA

Some 760,000 South Koreans who have received a first dose of AstraZeneca's COVID-19 vaccine will be offered Pfizer as a second shot due to shipment delays from the global vaccine sharing scheme COVAX, the government says.

Several countries, including Canada and Spain, have already approved similar dose-mixing, mainly due to concerns about rare but potentially fatal blood clots linked to the AstraZeneca vaccine.

A Spanish study found giving a dose of the Pfizer shot to people who had already received the AstraZeneca vaccine is highly safe and effective, according to preliminary results.

Some 835,000 doses of the AstraZeneca vaccine from COVAX were scheduled to arrive by the end of June, which South Korea planned to use mainly as a second shot for around 760,000 health and frontline workers who had received their first dose in April.

With the shipment delayed to July or later, the country has used up available AstraZeneca reserves to meet stronger than expected participation in its vaccination campaign.

More than 27 per cent of its 52 million population have been inoculated with at least one dose of a coronavirus vaccine as of Thursday, and the country is on track to meet a target of 70 per cent by September.

The government expects to receive 80 million vaccine doses - from AstraZeneca, Pfizer, Johnson & Johnson and Moderna - in the third quarter, including 10 million in July.

South Korea last month said it will conduct a clinical trial that mixes COVID-19 doses from AstraZeneca with those from Pfizer and others.

It has so far run a trial in 100 health workers to examine the formation of antibody and other immune effects, Korea Disease Control and Prevention Agency (KDCA) director Jeong Eun-kyeong told a briefing on Thursday.

South Korea reported 507 new infections by midnight on Thursday, for a tally of 150,238 cases, the KDCA said, with a death toll of 1996.

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