According to the UK Health Security Agency (UKHSA), the COVID-19 booster vaccine dose reduces the risk of death due to the Omicron variant by 95 percent in people aged 50 or over.
The findings of UKHSA show that about six months after the second dose of any of the COVID-19 vaccines, protection against death due to the Omicron variant was around 60 percent in those aged 50 and over. However, this increased to about 95 percent two weeks after receiving a booster vaccine dose.
The data of UKHSA continue to exhibit high levels of protection against hospitalization from the booster. Effectiveness against hospitalization was around 90 percent for the Pfizer-BioNTech shot, dropping to 75 percent 10-14 weeks after the booster.
After a Moderna booster (mRNA-1273), vaccine effectiveness against hospitalization was 90 percent to 95 percent up, for 9 weeks after vaccination. However, UKHSA points out longer follow-up data is not yet available and these figures may change with time.
“The evidence is clear, the vaccine helps to protect us all against the effects of COVID-19 and the booster is offering high levels of protection from hospitalization and death in the most vulnerable members of our society,” said Dr. Mary Ramsay, Head of Immunisation at UKHSA.
The UKHSA also issued an initial analysis of vaccine effectiveness against the Omicron sublineage called BA.2, which is growing in Britain and Denmark, finding a similar level of protection against symptomatic disease.
“After two doses effectiveness was 9 percent and 13 percent respectively for BA.1 and BA.2, after more than 25 weeks. This increased to 63 percent for BA.1 and 70 percent for BA.2 from two weeks following a booster vaccine,” the UKHSA noted.