DENMARK – According to a Danish study, the omicron BA.2 subvariant is inherently more contagious and more capable of infecting vaccinated people than any other Covid strain, but vaccinated people don’t transmit it as easily as the unvaccinated.
According to the study, the new subvariant, which has quickly become dominant in Denmark, spreads more easily across all groups, regardless of gender, age, household size, or vaccination status.
The study, which looked at coronavirus infections in over 8,500 Danish households between December and January, discovered that people infected with the BA.2 subvariant were roughly 33% more likely to infect others than those infected with the BA.1 subvariant.
The “original” BA.1 subvariant accounts for more than 98 percent of Omicron cases worldwide, but in Denmark, its close cousin BA.2 has quickly become the dominant strain, dethroning BA.1 in the second week of January.
“We conclude that Omicron BA.2 is inherently substantially more transmissible than BA.1, and that it also possesses immune-evasive properties that further reduce the protective effect of vaccination against infection,” the study’s researchers said.
The study, which was led by a team of scientists from the University of Copenhagen and the Danish Health Ministry, among other institutions, has not yet been peer reviewed.
Because of the pandemic’s urgency, researchers have been publishing their findings before they have been reviewed by other experts in the field.
“If you have been exposed to Omicron BA.2 in your household, you have 39% probability of being infected within seven days. If you instead had been exposed to BA.1, the probability is 29%,” lead study author Frederik Plesner said.
This implies that BA.2 is approximately 33% more infectious than BA.1.
BA.2 cases have also been reported in the United States, the United Kingdom, Sweden, and Norway, but to a much lesser extent than in Denmark, where it accounts for approximately 82 percent of cases.
The study also found that BA.2 was relatively better than BA.1 at infecting vaccinated and booster-vaccinated people, indicating that the subvariant had greater “immune evasive properties.”
Vaccines, however, continued to play an important role, as both booster-vaccinated and fully vaccinated individuals were less likely to become infected and transmit either subvariant when compared to those who had not been vaccinated.
Preliminary SSI analysis shows there is no difference in the risk of hospitalization between BA.2 and BA.1.
According to the UK Health Security Agency, the study also confirms preliminary research from England, which found that BA.2 appears to have a significant growth advantage over BA.1.
In Denmark, more than 80% of the population has been fully vaccinated, and more than 60% has received a booster dose.
According to the CDC, 63 percent of the total population in the United States is vaccinated, and approximately 41 percent of those vaccinated have received a booster.