In a press release published this Saturday, January 23, 2021, the High Authority for Health recommends extending the time between the two doses of the Pfizer and Moderna vaccines to six weeks. The objective is to accelerate the vaccination of a greater number of vulnerable people and thus avoid the saturation of the health system.
Getting the first dose to more vulnerable people
With the arrival of new variants of the coronavirus and in a context of gradual supply of vaccine doses over the year 2021, the health authorities wish to accelerate the vaccination campaign in France. This is why the Haute Autorité de Santé looked into the possibility of postponing the second dose of mRNA vaccine “ in order to ensure that a larger number of vulnerable people benefit from the first dose, before the epidemic situation deteriorates further “. This is what the HAS said in a press release published this Saturday, January 23, 2021.
According to her and in line with the opinions of the World Health Organization, the National Agency for Medicines Safety (ANSM) and Public Health France, “ it seems reasonable to extend for all the administration time of the second dose of mRNA vaccines to 6 weeks, the first dose already offering protection against the virus. “
Vaccinate 700,000 more people in the first month
To study the impact of a delay of 42 days instead of 21 between the two injections of the two mRNA vaccines (from Pfizer BioNtech and Moderna), the HAS based itself on models from the Pasteur Institute. The results showed that “ Whatever the hypothesis adopted on the vaccination rate, these models show that this lengthening makes it possible to vaccinate the populations most at risk more quickly “. Based on this observation, 700,000 additional people would be vaccinated in the first month of implementation of the measure.
A “limited” risk of loss of efficiency
Regarding the effectiveness of this new measure, the HAS considers that “the risk of loss of effectiveness seems limited”. Indeed, the results of phase 3 trials for mRNA vaccines have shown a ‘eEfficacy of the Comirnaty® vaccine from Pfizer BioNtech which starts from the 12th day after the first dose and that of the Moderna vaccine from the 14th day after the first dose “. Stating that no consensual position has been observed between the different countries, the HAS recommends that ” the administration of the second dose is postponed to 6 weeks for the two mRNA vaccines, reaffirming the essential nature of the administration of the second dose “.
