Vaccine Supply Eases... Will Vaccination Interval '6 Weeks → 4 Weeks Readjustment' Gain Momentum?

Today, 1.393 million doses of Moderna and 3.428 million doses of Pfizer will arrive tomorrow.

[Image source=Yonhap News]

As Moderna's COVID-19 vaccines, which had jeopardized the domestic vaccination plan for the second half of the year due to successive supply disruptions, are arriving one after another, the vaccine supply situation is easing. Accordingly, there is speculation that efforts to shorten the interval between the first and second doses of Pfizer and Moderna vaccines, which had been extended to 6 weeks, back to 4 weeks will gain momentum.

According to the quarantine authorities on the 7th, the recommended intervals between the first and second doses of Pfizer and Moderna's COVID-19 vaccines are 3 weeks and 4 weeks, respectively. Initially, the government followed the pharmaceutical companies' recommendations but extended Pfizer's dosing interval by one week to 4 weeks in July for the convenience of medical institutions. Shortly after, when Moderna notified that its monthly supply would be reduced to less than half of the originally planned 8.5 million doses at the beginning of last month, the intervals for both Pfizer and Moderna vaccines were uniformly extended to 6 weeks.

The problem is that to comply with the originally recommended dosing intervals by the pharmaceutical companies, the second dose schedules must be changed starting next week. Since Pfizer vaccines were used in the first week of large-scale vaccinations targeting the general population aged 18 to 49, the second dose should be administered starting from the 16th. Those under 40 who received vaccines through autonomous local government vaccinations since mid-last month have already exceeded the 3-week interval.

In particular, those waiting for the second dose cannot make same-day reservations for leftover vaccines through social networking services (SNS). Because of this, among those who received Pfizer or Moderna vaccines around mid-last month, complaints have arisen such as, "Even though there are leftover vaccines, why can't we get vaccinated according to the originally recommended dosing intervals?"

Currently, to use leftover vaccines for the second dose, one must be on the medical institution's standby list. Even then, vaccination is only possible between 5 to 6 weeks after the first dose. Only in cases where the second dose must be expedited due to personal reasons such as travel can the interval be changed to within 3 to 5 weeks at the same medical institution where the first dose was administered. A task force official stated, "To increase the use of leftover vaccines for the second dose, we are reviewing system improvements to allow changing the date to receive leftover vaccines even if the medical institution for the second dose reservation and the standby list are different, and to enable same-day reservations via SNS."

Professor Cheon Eun-mi of the Department of Respiratory Medicine at Ewha Mokdong Hospital said, "Since the extension of the dosing interval was due to vaccine shortages, if supply has become stable, it should be readjusted to 3 to 4 weeks as soon as possible. Especially as the government is discussing phased easing of quarantine measures, accelerating the second dose is most important to bring that timeline forward."

This content was produced with the assistance of AI translation services.