The zombie virus broke out again just because of a kiss

There are no humans in the UK because it has been 28 weeks since the zombie virus outbreak. People were infected and turned into zombies, but after 28 weeks, the zombies lost their carriers and they all died. But among the infected people there are survivors who may have antibodies in their bodies to fight the zombie virus. Although they did not become zombies, but they still have the zombie virus in their bodies. The virus was then spread once again, this time possibly worldwide.