Covid-19: New sub-variant of Omicron now circulating in Bulgaria

A 50% rise in the incidence of COVID-19 has been recorded in the country over the past week

Seven samples (6 in Sofia-city and 1 in Kyustendil) with Omicron subvariant VA.5 were detected in Bulgaria after whole genome sequencing of 88 samples taken from patients with SARS-CoV-2.

The samples were taken between 5 May and 3 June and were sent from 13 different medical institutions in 16 districts of the country. The Omicron viral variant was detected in all 88 clinical samples, with the ratio of sub-variants as follows: BA.2 (76.1%), BA.2 and its sub-variants combined (92%). BA.5 was detected in 8% of the samples tested.

The MoH recommends the administration of a second booster and RNA vaccine against COVID-19 in persons over 18 years of age.

In May this year, two Omicron sub-variants, BA.4 and BA.5, were declared "variants of concern" by the World Health Organization and ECDC. Omicron sub-variants BA.4 and BA.5 were first reported in South Africa, in January and February 2022 respectively, and are now dominant there.

BA.4 and BA.5 have many of the mutations inherent in the originally detected Omicron variant, but share more features with the BA.2 variant. They have a number of additional mutations, some of which may alter the characteristics of the virus.

Both new variants carry the L452R mutation, a mutation in the so-called spike protein gene that was previously found only in the SARS-CoV-2 Delta variant. The spike protein is important because it is used by the virus to infect human cells and determines how easily the virus is transmitted. This mutation makes the virus more infectious and may help it partially evade immune defences.

A 50% increase in the incidence of COVID-19 has been reported in Bulgaria in the last week. There has also been an increase in the weekly positivity rate of the tests performed - 9.98% of the tests were positive, an increase of 73%. Data from the National Center for Infectious and Parasitic Diseases show that as of June 29, the 14-day incidence rate in the country was 56.69 per 100,000 population. In view of the increasing number of COVID-19 cases in the country and the already detected sub-variant BA.5 of Omicron in the country, the Ministry of Health urges:

· Individuals with complaints and symptoms characteristic of COVID-19 (headache, severe fatigue, sore throat, runny nose, sneezing, loss of appetite, etc.) should isolate and consult a physician.

- In the presence of symptoms, even mild ones, like stuffy or runny nose, the ministry advise to postpone meeting other people in order to protect them from possible infection with SARS-CoV-2.

- Wearing protective face masks indoors and in crowded places - public transport, shopping malls, shops, bazaars, railway stations, bus stops, etc. - is highly recommended.

- Keep your distance in public places, if possible avoid places where many people are crowded at the same time.

- Wash your hands with soap and water and, if not possible, use an alcohol-based hand sanitizer.

Vaccination against COVID-19 remains the surest way to protect against severe illness, hospitalisation and long-term health consequences. The elderly, and anyone else whose immunity is weakened, are particularly at risk when infected with SARS-CoV-2. People who belong to this risk group and anyone suffering from chronic diseases are advised to be vaccinated against COVID-19 as early as possible. Vaccines against COVID-19 also protect against severe disease when infected with Omicron sub-variants BA.4 and BA.5.

The administration of a second booster iRNA vaccine is now also allowed in Bulgaria for persons aged 18 and older who have completed a two-dose vaccination course.