Extending Vaccination Intervals or Halving Dosages? Controversy Over UK and US Vaccine Plan Revisions

[Image source=Reuters Yonhap News]

[Asia Economy Reporter Cho Hyun-ui] As the United States and the United Kingdom, which have started COVID-19 vaccination, are not progressing with the vaccination process as quickly as expected, measures to modify the vaccination method are being considered.

On the 3rd (local time), The New York Times (NYT) reported that the impact of such measures on vaccine efficacy is not yet clearly understood, and there are concerns that sudden changes in plans could worsen vaccine distrust.

The UK government announced on the 30th of last month that the interval between the first and second doses of the vaccine would be extended from the existing 3-4 weeks to 12 weeks. The UK’s stance is to delay the second dose in order to maximize the number of people receiving the first dose. Since some immunity is formed with just the first dose, increasing the number of people vaccinated could more quickly curb the spread of the virus.

However, American experts are generally skeptical of this strategy. They point out that there is insufficient data to confirm that vaccine efficacy will be maintained if the second dose is delayed.

In the US, there are also concerns that delaying the second dose and expanding the first dose target group will not actually increase the vaccination rate. The main reasons for the lower-than-planned vaccination rate are related to logistical issues such as distribution delays and manpower shortages.

In the US, to expand the vaccination target, a plan to reduce the vaccine dose per person by half is being considered. Moncef Slaoui, chief advisor of the US vaccine development program 'Operation Warp Speed,' announced that they are studying the possibility of administering half the dose of the Moderna vaccine.

He explained that in the Moderna vaccine clinical trial targeting adults aged 18-55, those who received two doses of 50㎍ (micrograms, one-millionth of a gram) showed the same immune response as those who received two doses of the known appropriate dose of 100㎍.

Slaoui said that he is discussing the 'half-dose vaccination' plan with the Food and Drug Administration (FDA) and Moderna, and that the actual implementation depends on the FDA.

However, local experts evaluate this plan as worth considering based on scientific data but are cautious about guaranteeing actual efficacy. Dr. John Moore, a vaccine expert at Cornell University, said that 'half-dose vaccination' does not work for all vaccines and added, "It is not something I would want to do unless absolutely necessary."

Dr. Natalie Dean, a biostatistician at the University of Florida, also expressed skepticism, saying that this dosing method has not been thoroughly verified in clinical trials. She pointed out that sudden changes in vaccination plans could deepen public distrust in vaccines.

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