Pfizer vaccine. Is it useful to extend the second dose to three months?

To delay the second dose or not to delay? Shift the recall for a few weeks or even three months? Now these are the dilemmas. A decision was made just over 10 days ago. On May 5, in fact, the Ministry of Health gave its authorization to postpone the second dose of Pfizer and Moderna vaccines to 42 days, while previously the times were respectively 21 and 28 days.