mRNA Covid vaccines can be frozen again, say Catalan researchers

The mRNA Covid-19 vaccines can be frozen again without losing any of their immunity capacity, as researchers at Barcelona's Hospital del Mar medical investigations institute and the city's Pompeu Fabra University have found out and published on Monday. 

For the study, they used rejected Pfizer-BioNTech and Moderna coronavirus vaccines that had already been prepared for administration. Some of these were given to lab mice, others were frozen at -20ºC for a month, and the third batch was frozen at -80ªC before administering them. 

In all cases, animals had the same immunity response against SARS-CoV-2, and none showed secondary effects. 

Researchers claim that freezing vaccines that had already been prepared for administration opens the door to new opportunities, such as maximizing the potential of all available doses, reducing waste, and sending ready-to-administer vaccines to developing countries. 

Freezing the vaccines after they have been prepared in the country they were manufactured will allow for them to be given despite their short lifecycle, as the time to administer them is, at least, a month.

The study also opens the door to preparing the vaccines in cities and then administering them in rural areas. 

According to the World Health Organization (WHO), 240 million Covid-19 vaccine doses have been lost in Europe and Japan alone, and some of those sent to developing countries by the COVAX initiative could not be administered as they had already expired. 

Researchers had already proved in previous experiments that ready-to-administer Covid-19 doses could be transported at normal temperatures for at least three hours.