Sunday's German Grand Prix was the first race this season in which a driver from both teams had finished ahead of Vettel, who has built a dominant lead in the championship after winning six of the first eight races.
In taking the chequered flag, and with Vettel only fourth, Lewis Hamilton managed to close the gap to Vettel to 82 points, whilst Alonso is 86 adrift after finishing second.
The Spanish double world champion knows the only way to hunt down Vettel is for both himself and old rivals McLaren to continue their pincer-movement assault on the 24-year-old.
"If you start from pole position, you have a second advantage in your car and you lead the whole race, it's very easy," said Alonso with regard to a number of Vettel's performances this season.
"When there is more competition you need to race in a different way, to be perfect in all things: the start, pit stops, qualifying etcetera.
"In Germany they maybe had some difficulties in one of the areas, but they are still very, very quick.
"They were on pole (with Mark Webber), and for me they are by far the favourites for the next race in Budapest (Hungarian Grand Prix on Sunday).
"If we have races like in Germany and we are on the podium and he (Vettel) isn't, then there is a small chance to recover the gap in the championship.
"But we also need the best possible performance from our team-mates, and we need the best McLaren performance as well, to see the McLarens very, very strong and taking points from Red Bull."
Ferrari team principal Stefano Domenicali said they needed to launch an all-out assault on Red Bull.
"What we need to do is attack every race and then later on see what is happening with the championship," said Domenicali.
"Of course the more drivers and cars that can fight, the easier it is to score more points and minimise the gap because at the moment it is still very big."