"Booster Shots Provide 90% Infection Prevention Effectiveness Regardless of Vaccine Type, UK Study Reveals"

Messenger RNA (mRNA) Vaccines Like Pfizer and Moderna Are the Most Effective

Vaccination scene. The photo is unrelated to specific expressions in the article. [Image source=Yonhap News]

[Asia Economy Reporter Yoon Seul-gi] Most COVID-19 vaccine booster shots (additional doses) have been shown to increase antibody levels when given as a 'heterologous vaccination' (mix-and-match). The effects of Pfizer and Moderna vaccines were particularly notable.

On the 4th (local time), according to the New York Times (NYT) and others, researchers at the University of Southampton in the UK reported that antibody levels increased by at least 90% after using a total of seven different COVID-19 vaccines as booster shots on fully vaccinated individuals.

The researchers administered seven types of vaccines, including the same type used for the first and second doses, to 2,878 people who had completed their second dose with either the AZ vaccine or the Pfizer vaccine. The vaccines used for the booster shots were Moderna, Pfizer, Janssen, AstraZeneca (AZ), Novavax, CureVac, and Valneva. No countries have yet approved the use of CureVac and Valneva.

Four weeks after measuring the participants' COVID-19 antibody levels, all seven vaccines showed increased antibody levels. The researchers explained, "The booster shot's effectiveness in preventing COVID-19 infection reached 90%, meaning that any type of vaccine is effective."

The NYT reported that mRNA vaccines like Pfizer and Moderna were more effective as booster shots. In the group that received Pfizer for the first and second doses, those who received the Valneva vaccine as a booster showed a 1.31-fold increase in antibodies compared to the control group, while Moderna showed an 11.49-fold increase. When both the initial doses and the booster were AZ vaccines, antibody levels increased only 3.25 times compared to the control group, but Pfizer showed a 24.5-fold increase and Moderna a 32.3-fold increase.

The researchers stated, "Most side effects reported by those who received booster shots were fatigue, headache, and arm pain," adding, "Serious side effects after any booster shot were rare."