You need not worry about a slight delay after (what in many countries is considered) the minimal/maximum period of 3/6 weeks for the Comirnaty/BioNTech/Pfizer vaccinations.
The goal of the minimal period is to swiftly offer protection against the delta variant.
The maximum period (6 weeks) is considered to offer the optimal protection for this specific vaccination product.
Since these values are based on practical experience collected and shared around the world, it is unlikely that individual countries will have radically different recommendations.
One should, however, always check the recommendations of the country one is travelling to, as well as being aware of the different names used for the same vaccination product.
Comirnaty is the name of the vaccine, developed by BioNTech and produced by Pfizer (as one of many products).
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For Comirnaty/BioNTech/Pfizer the recommendation is 3 to 6 weeks.
At the beginning of April 2021, a vaccination interval of 6 weeks was initially recommended for the mRNA vaccines, as this should achieve the best balance between good individual protection and optimal civil protection. Findings on vaccination with regard to the delta variant show a significantly better protective effect after the second vaccine dose, especially against severe courses. A shorter vaccination interval therefore leads to better protection both for the individual and for the population in a timely manner.
For Spikevax/Moderna the recommendation is 4 to 6 weeks.
For Vaxzevria/AstraZeneca the recommendation is 9 to 12 weeks.
The studies showed that the interval between the two vaccine doses influences the effectiveness of the vaccination and a longer time interval has a positive effect on the level of vaccination protection. The effectiveness of a double vaccination with an interval of 4-8 weeks was about 50%, while the effectiveness with an interval of 8-12 weeks was about 72% and with a vaccination interval of> 12 weeks it was about 75%. These results are supported by immunogenicity data, which show that when the standard dose is administered, increasing the dose interval leads to higher antibody levels and higher GMT values (<6 weeks: 22,222 (95% CI 20,360-24,225) vs. 9-11 weeks : 34,754 (95% CI 30,287-39,879).