Pfizer: "Vaccine Effectiveness Decreases Every Two Months"…Experts Divided, Some Say "Still Sufficient Now"

Pfizer: "Vaccine efficacy decreases by 6% every two months after the second dose"
FDA: "No additional booster needed"

[Image source=Yonhap News]

[Asia Economy Reporter Na Ye-eun] The debate surrounding additional COVID-19 vaccinations (booster shots) is intensifying. Pharmaceutical companies such as Pfizer and Moderna emphasize the necessity of booster shots, while experts from the World Health Organization (WHO) and the U.S. Food and Drug Administration (FDA) maintain a cautious stance.

Those advocating for the need for booster shots present evidence that antibody levels decline over time after vaccination. Israel, the first country in the world to begin administering booster shots in July, announced, "According to the Ministry of Health's research, the efficacy of the Pfizer vaccine, which was 94% effective against the original COVID-19 virus, dropped to 64% following the spread of the Delta variant."

Pfizer submitted results to the U.S. FDA showing that vaccine efficacy decreases by 6% every two months after completing the second dose and applied for booster shot approval. Initially, the vaccine showed 96.2% efficacy, but this dropped to 90.1% after two months and 83.7% after four months.

Moderna also revealed in its own research that "vaccine effectiveness decreases over time." According to the U.S. CNBC broadcast, Moderna confirmed breakthrough COVID-19 infections among participants in its Phase 3 vaccine clinical trials. From December last year to March this year, among 11,431 participants who completed the second dose, 88 experienced breakthrough infections. However, among 14,746 participants who completed vaccination between July and October last year, 162 had breakthrough infections.

Stefan Bancel, CEO of Moderna, stated, "Comparing last year's vaccine recipients with recent ones shows an increased risk of breakthrough infections, proving the impact of waning immunity," and argued, "Booster shots are necessary to maintain a high level of protection."

U.S. FDA.
Photo by Yonhap News

On the other hand, WHO and FDA experts oppose the pharmaceutical companies' views. According to the New York Times and Wall Street Journal on the 15th (local time), the U.S. FDA stated that the currently administered vaccines are sufficiently effective in preventing severe illness and death related to COVID-19 without additional doses.

This aligns with the opinion expressed on the 13th (local time) by 18 health experts, including scientists from WHO and the U.S. FDA. They wrote in the British medical journal The Lancet, "Even if antibody levels decline, memory cells exist, and two doses alone provide sufficient preventive effect," adding, "Except for some immunocompromised individuals, booster shots do not appear necessary for the general public at this time."

Internationally, concerns have been raised that nationwide booster shot campaigns in developed countries could disrupt vaccine supplies to developing and underdeveloped countries.

Meanwhile, Singapore will begin administering COVID-19 booster shots to the elderly starting at the end of this month. The United Kingdom and France will also start booster shots to respond to COVID-19 during the winter season.