It all seems very odd that this variant has suddenly appeared and the governments reaction to it.
We are of course not told if the widely bandied figure if the vaccination may be 40% less effective means that the vaccine is 40 % less able to prevent transmission or it is 40% less able to prevent hospitalisation /serious illness
although the he WHO 20 hours ago said
Transmissibility: It is not yet clear whether Omicron is more transmissible (e.g., more easily spread from person to person) compared to other variants, including Delta. The number of people testing positive has risen in areas of South Africa affected by this variant, but epidemiologic studies are underway to understand if it is because of Omicron or other factors.
Severity of disease: It is not yet clear whether infection with Omicron causes more severe disease compared to infections with other variants, including Delta. Preliminary data suggests that there are increasing rates of hospitalization in South Africa, but this may be due to increasing overall numbers of people becoming infected, rather than a result of specific infection with Omicron. There is currently no information to suggest that symptoms associated with Omicron are different from those from other variants. Initial reported infections were among university students—younger individuals who tend to have more mild disease—but understanding the level of severity of the Omicron variant will take days to several weeks.
On 26 November 2021, WHO designated the variant B.1.1.529 a variant of concern, named Omicron, on the advice of WHO’s Technical Advisory Group on Virus Evolution (TAG-VE). This decision was based on the evidence presented to the TAG-VE that Omicron has several mutations that may have an impact...
www.who.int
I will take the charitable view that it is not the case that the government are sitting on a load of vaccines that are shortly to reach their use by date and they need to try and panic people fast to take up their third doses as this is the only thing that may make sense