Omicron sub-variant XBB.1.16: What you need to know

Thailand has recently reported 27 cases of the new Omicron sub-variant XBB.1.16, leading authorities to closely monitor its transmission speed and the ease with which it can escape people’s ability to handle the virus following months, if not years, of vaccinations and herd immunity development.

The Ministry of Public Health is recommending that individuals, particularly senior citizens and those with underlying health conditions, receive booster shots due to growing concern about the risk of new outbreaks. Here is an overview of this new sub-variant.

On March 30, the World Health Organization (WHO) identified XBB.1.16 as a Variant Under Monitoring (VUM) after its initial detection in India in January. Originally, it combined with Omicron’s BA.2.10.1 and BA.2.75 sub-variants, and its mutation was found in the spike proteins of E180V, F486P, and K478R. The mutation on the spike protein’s 478 spots has increased its transmission speed.

Lab tests have revealed that XBB.1.16 can be transmitted more efficiently than XBB.1 and XBB.1.5, suggesting it could spread more rapidly across the globe. However, no scientific evidence supports the claim that it will cause more severe symptoms than earlier forms of the virus.

Symptoms of XBB.1.16 are similar to those of other sub-variants, such as fever, coughing, sore throat, and a runny nose. More concerning, however, are reports of patients experiencing itchy eyes, pink eye, or even “sticky eyes,” as these symptoms have not been linked to other sub-variants.

Some specialists have downplayed these reports, as they have only been observed in children in India. Dr Supakit Sirilak, chief of the Department of Medical Sciences, stated that eye irritation has not been confirmed as a symptom related to XBB.1.16.

On Tuesday, the Department of Medical Sciences confirmed 27 cases and one death linked to this new sub-variant. The deceased was an elderly individual. The department expects to observe a surge in caseloads following the Songkran celebrations. It aims to collect at least 700 samples per week to monitor the strain’s spread.

It is estimated that XBB.1.16 may now account for 10% of all new Covid infections, compared to XBB’s 30%. By the middle of next month, the department believes XBB.1.16 will become the dominant strain.

As a result, the department is following WHO’s advice to carefully monitor the situation since XBB.1.16 has gone from comprising 0.21% of all new Covid infections globally in late February to an estimated 3.96% a month later. In the US, it accounted for approximately 7.2% of all Covid samples from April 9-15.

The Department of Disease Control (DDC) anticipates a small wave of Covid-19 outbreaks beginning in May, with numbers peaking in June. The number of cases will then decrease, following the typical pattern of influenza outbreaks.

Upon students’ return to classes in May, schools will experience a minor wave, according to the DDC. In response, the Ministry of Public Health assures that sufficient medicines and other resources have been prepared to handle such outbreaks.

The ministry advises the public to exercise extreme caution in preventing infections. People should maintain self-preventive measures, such as wearing masks in public areas, frequently washing hands, practising social distancing, and getting booster shots.

The ministry emphasises that older adults and individuals with chronic diseases should immediately get a booster, particularly if their last dose was more than three months ago.

The ministry continues to offer free vaccinations and currently has over 10 million multi-based vaccine platform doses. It has also issued guidelines for vaccine administration, recommending that individuals receive an annual dose, similar to regular flu shots. These vaccines will be given concurrently, starting next month.