Thursday, January 20, 2022

Norwegian Institute of Public Health Also Reports A Rapid Increase In Omicron BA.2 Subvariant


#16,521

Following the posting of today's earlier blog (see Denmark SSI: Omicron Subvariant BA.2 Now Accounts For Nearly Half Of All Danish Cases), I've found another Scandinavian country reporting a sharp increase in the Omicron BA.2 subvariant; Norway.

For additional background on the BA.2 subvariant, you'll want to refer to my previous blog, but in short BA.1 has been the dominant Omicron variant (>99%) globally for the past couple of months, but now its sibling (BA.2) is suddenly making major inroads in northern Europe. 

It isn't known what - if any - difference infection with BA.2 may have over BA.1, although there are hints that BA.2 may be more transmissible. 

Yesterday Norway's NIPH published their (week 2) Epidemiological summary of COVID, which finds BA.2 outpacing BA.1 over the past couple of weeks.   While they report a reduction in hospital admissions over the previous week, it is too soon to know what impact BA.2 will have on their COVID wave. 

(translated)

Weekly report covid-19 for week 2 has been published

Published 19.01.2022

So far, 218 new patients have been admitted to hospital with covid-19 detected in week 2, of which 112 (51%) with covid-19 as the main cause. This is a preliminary 23% decrease in new admissions with covid-19 as the main reason after 145 in week 1.

          (Excerpt)

Summary for week 2

Severe covid-19 disease
  • So far, 218 new patients have been admitted to hospital with covid-19 detected in week 2, of which 112 (51%) with covid-19 as the main cause. This is a preliminary 23% decrease in new admissions with covid-19 as the main reason after 145 in week 1. The number of new patients admitted to hospital last week can be adjusted upwards. Small adjustments in figures for previous weeks may also occur.
  • The number of admissions for covid-19 (the main cause) continues to decline, probably because the omicron variant causes less serious illness and more are well protected through vaccination. The number of hospitalizations of people infected with SARS-CoV-2, but who have another main cause of hospitalization, is increasing. This is because there is widespread infection in the community, including among those who have to be hospitalized for reasons other than covid-19. These patients now make up half of the new admissions.
  • Last week, there was an increase in the number of new hospital admissions in the age group 0-17 years, a stable trend in the age group 18-29 years, otherwise there has been a decrease in other age groups.
  • The number of new patients admitted to the intensive care unit is currently 18 in week 2, a 42% decrease from week 1 (31).
  • Among 112 new patients admitted to hospital in Norway with covid-19 as the main cause in week 2, 47 (46%) were unvaccinated, 24 (24%) were vaccinated with two doses and 27 (26%) were vaccinated with three doser. Primary vaccinated people who have been admitted to hospital with covid-19 as the main reason for hospitalization have a higher median age, and a larger proportion of them have underlying medical conditions that give a moderate or high risk of a serious course of covid-19, compared with the unvaccinated.
  • So far, 24 covid-19 associated deaths have been registered in week 2 after 22 in week 1. The number for week 2 can be adjusted upwards. In week 2, the median age was 81 years (lower-upper quartile: 74 - 87 years).
(SNIP)

Virological monitoring
  • Omikron became dominant in Norway through Christmas and there has been a rapid increase in all counties. The proportion of omicron cases increased rapidly from around 6% in week 49 to 89% in week 1 and 94% in week 2. There are regional differences, but an increase in most counties.
  • A variant of SARS-CoV-2, so far defined as an omichronic subvariant, BA.2, is increasing rapidly in Norway. From 7 detections on 4 January to a total of 611 detections on 19 January (mainly in Oslo), this edition of omikron is growing strongly compared to the original omikron, BA.1. The properties of the virus are not known other than that it is more contagious than BA.1 and increases correspondingly in Denmark and Sweden and may appear to take over for BA.1 already.

While the future course of the COVID pandemic is unknowable, two European countries reporting a sudden surge in the BA.2 subvariant - and predicting it will soon overtake the dominant Omicron strain - is worth noting. 

Stay tuned.