The phrase "again prevent" is not standard in written English and may cause confusion.
It could be used in contexts where you want to emphasize the repetition of preventing something, but it is better to clarify the meaning.
Example: "We must again prevent any further delays in the project."
Alternatives: "stop once more" or "halt again".
"What may happen is a new form of regulation could come into force that would again prevent applications being made".
Moscow's mayor, Yuri M. Luzhkov, an outspoken opponent of gay rights groups, vowed Monday to again prevent a gay parade in the city.
Therefore we will, as a matter of urgency, take the necessary steps to once again prevent vehicular access whilst we conduct a full safety assessment.
During the June term of the court, Desha's lawyers used a number of peremptory challenges to again prevent the court from empaneling a jury.
To ensure democracy, the election commission needs resources and technical assistance to conduct the second round elections and to once again prevent voter fraud and quickly adjudicate election complaints.
The slim special features and the theoretical lack of repeat viewing (it's not exactly a movie to be enjoyed over and over again) prevent me from recommending a purchase for the casual moviegoer.
Domestic upheavals once again prevented united and convincing action.
12.19pm GMT Finland 0-0 Sweden, 11 55, 1st period Jonathan Ericsson redirects a shot, but Lehtonen is all over it, again preventing a rebound.
The Uruguayans, who won their 15th title in Argentina in 2011, pushed Venezuela back in the second half but lacked finishing and Muslera again prevented them going further behind with a fine save from Adalberto Peñaranda in the 68th.
It was an hour before Jeremy Lin, the rising star for the Knicks, took the court at Madison Square Garden and before much of Chinatown was going to be once again prevented from seeing its adopted son work wonders on the basketball court.
The makers of "Project X," knowing how short the teenage memory is, have now boldly, raunchily made the declaration again, preventing millions of young people from growing up without understanding that every 17-year-old is entitled to a drunken, deafening, topless, drug-filled, sex-crazed, property-destroying, life-endangering birthday.
