Geneva: Mixing and matching COVID-19 vaccines from different manufacturers is a "dangerous trend" and could lead to chaos as there is limited data on it on the practice, World Health Organisation (WHO) chief scientist Soumya Swaminathan said on Monday.
Addressing a COVID-19 media briefing, Swaminathan said, "Really want to caution folks, because there is a tendency now for people in countries which enough availability of vaccines to voluntarily start thinking."
"So it's a little bit of a dangerous trend here where we're in a data-free evidence-free zone as far as a mix and match there is limited data on mix and match. There are studies going on, we need to wait for that," she added. On the question of booster shots, WHO chief scientist said it will be a chaotic situation in countries if citizens start deciding when they should be taking a second, or a third, or a fourth dose.