Caution before fractionating COVID-19 vaccines

Affiliations

• ¹ Immunization, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland. wildersmitha@who.int.
• ² Institute of Social and Preventive Medicine, University of Berne, Berne, Switzerland. wildersmitha@who.int.
• ³ Heidelberg Institute of Global Health, University of Heidelberg, Heidelberg, Germany. wildersmitha@who.int.
• ⁴ Immunization, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland.
• ⁵ Faculty of Medicine, National Autonomous University of Mexico, Mexico City, Mexico.
• ⁶ Department of Health Security at the Finnish Institute for Health and Welfare, Helsinki, Finland.