Coronavirus Explainers
Omicron’s New Sub-Variant XBB1.16.1: What Do We Know So Far?
Senior Consultant, Pulmonologist at Delhi’s Sir Ganga Ram Hospital, Dr Dhiren Gupta spoke to the NDTV-Dettol Banega Swasth India team about Omicron’s mutated sub-variant, XBB1.16.1 and its effect on the immune system
New Delhi: India has been witnessing a surge in the number of coronavirus cases, and several medical experts have attributed the current surge to Omicron’s mutated sub-variant – XBB1.16.1. Omicron and its sub-variants have found be a dominating variant in India with ‘XBB’ being the most prevalent. The sub-variant has been found in over 13 States and Union Territories in India. Several states are rolling out guidelines for the citizens, for both home and their workplaces.
XBB1.16.1 is a mutation of Omicron’s infectious XBB1.16 variant. According to the Indian SARS-CoV-2 Genomics Consortium (INSACOG), 436 cases of XBB1.16.1 sub-variant have been detected in the country.
Senior Consultant, Pulmonologist at New Delhi’s Sir Ganga Ram Hospital, Dr. Dhiren Gupta, spoke to the NDTV-Dettol Banega Swasth India team about Omicron’s mutated sub-variant and how it is different from the previous variants.
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NDTV: What do we know so far about Omicron’s mutated sub-variant, XBB1.16.1, and how different IS it is from the previous variants?
Dr. Dhiren Gupta: We need to first look back at the kinds of strains and variants we have experienced so far, from Alpha, Delta and Omicron. All the strains and their variants affected the lungs; they led to an oxygen deficiency and multiple hospitalisations due to several health complications. Of all the strains, Omicron has had several mutations within short gaps. All the variants of Omicron were primarily affecting the upper respiratory tract and not the lungs or creating pneumonia problems or oxygen deficiencies among patients. The XBB1.16.1 is the recombinant strain of two omicrons.
There are three major differences between XBB1.16.1 and the previous variants.
It is more invasive to the immune system, so all individuals, with or without vaccination, are vulnerable to the new sub-variant. The new sub-variant is more infectious as the R0 (R naught – epidemiological metric used to measure the transmissibility of infectious agents) in it is much higher than the previous variants and strains. We have observed that XBB1.16.1 is hitting the immune system, spreading quickly, and its incubation period is also short.
NDTV: How does XBB1.16.1 affect the immune system, and are present antibodies efficient in fighting against it?
Dr. Dhiren Gupta: First of all, we need to understand the types of immune systems. The first one is innate immunity. It is the body’s first line of defence against infection or virus. Any virus or foreign body initially activates the innate immune system. Let’s imagine a virus named ‘Infection A’, invading the body; once it does, the body recognises it and starts producing antibodies to fight against it. This kind of immunity acts in a non-specific way.
Another type is adaptive immunity, also known as acquired immunity, which builds up once the body is exposed to the virus. So, if pathogens or viruses pass through innate immunity, then adaptive immunity kicks in. Unlike innate immunity, the adaptive immune system works in a specific way.
Now suppose a virus has changed its structure to a significant extent, so it mutates frequently, thus, making it difficult for the adaptive immunity to fight against it, and only innate immunity is at work, but it protects only to a certain extent. So, suppose, the vaccination an individual received in 2021 or 2022 and developed the antibodies, they will not be that effective against this sub-variant of Omicron. This particular sub-variant deceives the immune system. So, our immune systems are at risk.
NDTV: How different is XBB1.16.1 from the previous variants in terms of the duration it takes to show symptoms, its transmission rate, and the severity of the disease?
Dr. Dhiren Gupta: XBB1.16.1 is one and a half times more infectious than the previous Omicron variants. Omicron was already more infectious than the previous strains. So, it has a greater propensity to cause infection and spread infection in a closed group. Once it’s inside the body, it holds onto the body for a day or two. If we talk about symptoms, they are almost similar to the previous Omicron variants: fever, cough, and cold, body ache, nasal infection. But eye swelling and itchiness has been observed in the paediatric age groups.
NDTV: How effective are the current vaccines or booster doses against XBB1.16.1?
Dr. Dhiren Gupta: It is a difficult answer, as at present, we don’t have any adequate research conducted on XBB1.16.1. Without a good study in the Indian context and on Indian vaccines, it would be difficult to answer the question. But in general, it requires 18 times the antibodies produced by the previous infection to have some immune effect on the virus. I still recommend people to go for the vaccinations currently available.
NDTV: Is there a role for herd immunity and immunisation in preventing XBB1.16.1 and future outbreaks?
Dr. Dhiren Gupta: Generally, there are two types of herd immunities: vaccine-induced immunity and virus-induced natural immunity. It is better to have vaccine-induced immunity because virus-induced herd immunity can lead to a lot of deaths. Natural infection is virulent and can lead to a lot of complications as compared to the vaccine virus, which is suppressed or attenuated. Herd immunity makes it possible to protect the population from a disease, including those who can’t be vaccinated. But it has no role in preventing the new infection because of the constant mutation of the virus, which leads to a major antigen shift. It is difficult to rely on community infection to create herd immunity to the virus that keeps mutating.
It is to be noted that we need to have a good place for research simultaneously, as the mutation is happening within short spans of time.
NDTV: What preventive measures can we follow to avoid contracting the infection?
Dr. Dhiren Gupta: When it comes to precautions, we need to have a pragmatic approach. Firstly, get yourself vaccinated, especially with the influenza vaccine and other important routine vaccinations for all the age groups. The coronavirus outbreak has led to major backsliding on other important vaccinations, especially among the paediatric group. According to the World Health Organisation (WHO), 23 million children will be denied basic vaccines through routine immunisation services in 2020, a staggering figure.
At least influenza vaccination should be given to all the high-risk patients, as it will increase the innate immunity that will help fight against the virus to some extent. The golden principles of COVID-19 must be followed, which include hand washing, wearing a mask, and maintaining social distance. The kind of food we eat also plays a huge role in maintaining a healthy lifestyle. So, it is important to consume nutritious food.
NDTV: Will the COVID pandemic eventually become endemic in India?
Dr. Dhiren Gupta: The coronavirus pandemic has been there for more than three years, and now it appears to have become endemic in India. Patients without vaccination were developing moderate to severe forms of the disease until last year. But now, even though new cases are being reported, the share of Indians requiring hospitalisation has decreased. I believe the disease will become endemic because new mutations will keep coming in every season. We need to keep a close watch on the virus in the next three to five years.
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NDTV – Dettol have been working towards a clean and healthy India since 2014 via the Banega Swachh India initiative, which is helmed by Campaign Ambassador Amitabh Bachchan. The campaign aims to highlight the inter-dependency of humans and the environment, and of humans on one another with the focus on One Health, One Planet, One Future – Leaving No One Behind. It stresses on the need to take care of, and consider, everyone’s health in India – especially vulnerable communities – the LGBTQ population, indigenous people, India’s different tribes, ethnic and linguistic minorities, people with disabilities, migrants, geographically remote populations, gender and sexual minorities. In wake of the current COVID-19 pandemic, the need for WASH (Water, Sanitation and Hygiene) is reaffirmed as handwashing is one of the ways to prevent Coronavirus infection and other diseases. The campaign will continue to raise awareness on the same along with focussing on the importance of nutrition and healthcare for women and children, fight malnutrition, mental wellbeing, self care, science and health, adolescent health & gender awareness. Along with the health of people, the campaign has realised the need to also take care of the health of the eco-system. Our environment is fragile due to human activity, which is not only over-exploiting available resources, but also generating immense pollution as a result of using and extracting those resources. The imbalance has also led to immense biodiversity loss that has caused one of the biggest threats to human survival – climate change. It has now been described as a “code red for humanity.” The campaign will continue to cover issues like air pollution, waste management, plastic ban, manual scavenging and sanitation workers and menstrual hygiene. Banega Swasth India will also be taking forward the dream of Swasth Bharat, the campaign feels that only a Swachh or clean India where toilets are used and open defecation free (ODF) status achieved as part of the Swachh Bharat Abhiyan launched by Prime Minister Narendra Modi in 2014, can eradicate diseases like diahorrea and the country can become a Swasth or healthy India.