This column focuses on the risks posed by the new variant XBB.1.16, the further surge in cases in India and the need to maintain extreme caution to prevent a fourth Covid wave in India.
XBB.1.16 is mutating further
The new variant nicknamed “Arcturus” is mutating further. A total of 113 cases of a subvariant of XBB.1.16 called XBB.1.16.1 have been reported in India (India Today, Apr. 8, 2023). Most of these cases were found in Maharashtra and Gujarat. The latest INSACOG bulletin says that XBB.1.16 accounts for about 38.2 per cent of all new Covid infections in India.
Symptoms of XBB.1.16
The symptoms of the new variant are same as that of the parent Omicron strain. These include fever, cough, cold, runny nose, headache, body ache, abdominal pain, and diarrhea etc. Though this variant is highly infectious, there are no data so far to indicate that it causes a severe disease.
However, this variant can pose high risk to certain populations. These include the elderly or very young people, the immunocompromised, those who have comorbidities such as diabetes, lung disease, heart disease, renal failure, cancers, and patients who are administered with steroids or other immunosuppressant medicines. These individuals may be very vulnerable and they need to seek medical intervention if they display any Covid-like symptoms.
Latest COVID Figures
On Saturday, April 8, 2023, India logged 6,155 fresh Covid infections. In the last 24 hours, India recorded 11 deaths (New Indian Express, Apr. 8, 2023). The Union Health Ministry has advised the states to ramp up testing, monitor influenza-like illnesses to identify possible hotspots, and revalidate the preparedness of hospitals.
The positivity rate in India now stands at 3.39%; this is a worrisome figure and we all must remain watchful of the emerging trajectory of Covid infections across India.
The figure of active cases in India now stands at 31,194.
New Offshoot Strain is More Immune-evasive
XBB.1.16.1, the sub-lineage of XBB.1.16, is expected to be more immune-evasive than other Omicron strains as it got an extra mutation called T547I (TOI, Apr. 6, 2023). This means that this offshoot strain has mutations that enable it to escape the immune response of the host in the form of antibodies or activated T cells. This poses the risks of reinfections in people who have had prior infections. This also means that there would be reduced efficacies of vaccines or drugs targeting the Covid virus. On the other hand, the new variants are also more transmissible which means the virus is now more effective in infecting host cells and spreading from person to person.
XBB.1.16 versus XBB.1.5
XBB.1.16 is one among more than 600 Omicron subvariants circulating across the world, according to WHO (Time magazine, Apr. 4, 2023). XBB.1.16 is similar to XBB.1.5 that has been the dominant strain in the US in 2023. But the former has some additional advantage over the latter as it has acquired a new mutation in the spike protein of the virus, which is involved in infecting host cells. Though XBB.1.16 is so far concentrated in India and Nepal, it has the potential to spread across the world and trigger a fresh wave of the pandemic, as the new Omicron subvariant has potential for increased infectivity as well as increased pathogenicity.
Due to the surge in Covid cases due to XBB.1.16 and its offshoots, we must once again adhere to the standard SOPs as was done in earlier waves of infections. There is the likelihood of fresh restrictions or even lockdowns by the Union Health Authorities, even though no official announcements have been made so far. Meanwhile, it would be prudent to enforce Covid-appropriate behaviour once again.
Anyone with flu-like symptoms must mask up and isolate himself/herself. Medical personnel and healthcare workers must wear masks while taking care of people suspected to be infected.
People must avoid crowded places (as far as feasible), wear masks in public gatherings, wash their hands frequently, and maintain social distancing to reduce the chances of the virus spreading further.
There is also the need to enhance rate of full vaccinations (giving 2nd doses to those who have had only 1 dose of vaccine so far) and also increase the rate of booster shots (precautionary doses) in the elderly, and immunocompromised populations, and those with co-morbidities.
(The views expressed are persoal)