Britain's health authorities said on Friday that early laboratory analysis had showed the vaccine being offered to students should protect against the strain of meningitis behind an outbreak in southeast England that has killed two people.
The UK Health Security Agency said the strain belonged to a group of meningococci known as ST-41/44, which had been circulating in the country in recent years.
The confirmation that the Bexsero vaccine covers the strain had given "important reassurance," the agency said, while further analysis would continue.
UKHSA said 2,360 people had now received vaccinations and about 9,840 courses of antibiotics had been administered as part of the response. As of Thursday evening, 18 cases had been confirmed and 11 others were under investigation.
Authorities expanded vaccination clinics on Thursday after health officials warned they were not yet able to say the outbreak had been contained. Britain typically sees around one case of invasive meningitis per day, according to government estimates.
The outbreak has driven high demand for the MenB vaccine nationally, with pharmacy chain Boots reporting earlier this week that supplies across Britain were limited.
US President Donald Trump and Iran threatened to escalate their war by attacking energy and desalination facilities in the Gulf, a potential widening of hostilities that could deepen a regional crisis and add to concerns in global markets.
An Israeli airstrike on a police vehicle on Sunday killed three people in the middle of the Nuseirat camp in the central Gaza Strip, health officials said, hours after another person was killed in a strike on northern Gaza.
The Strait of Hormuz remains open to all shipping except vessels linked to "Iran's enemies", Iran's representative to the UN maritime agency was quoted as saying in Iranian media reports published on Sunday.
The Gulf Cooperation Council (GCC) has renewed its condemnation of continued Iranian attacks on member states, including the targeting of infrastructure and oil facilities, in flagrant violation of international law and a direct threat to regional security, stability and the safety of global energy supplies.