PTI Fact Check: NYC health department tweet on XBB.1.5 subvariant, vaccination misconstrued

New Delhi, Jan 25 (PTI) The NYC Department of Health and Mental Hygiene tweeted that the Omicron XBB.1.5 subvariant of coronavirus was "more likely to infect people vaccinated or (those who) already had COVID-19". A PTI Fact Check, however, found that the tweet was taken out of context and shared multiple times with misleading claims.

Two medical experts told PTI that there was no conclusive evidence that people vaccinated against COVID-19 were more vulnerable to the XBB.1.5 subvariant of Omicron, as claimed in the tweet.

The XBB.1.5 strain is a relative of the Omicron XBB variant, which is a recombinant of the Omicron BA.2.10.1 and BA.2.75 subvariants.

"Omicron subvariant XBB.1.5 now accounts for 73% of all sequenced COVID-19 cases in NYC. XBB.1.5 is the most transmissible form of COVID-19 that we know of to date and may be more likely to infect people who have been vaccinated or already had COVID-19", read the tweet posted by the NYC Department of Health and Mental Hygiene on January 13.

The graphics shared with the post showed 73 per cent of the COVID-19 cases were of the XBB.1.5 subvariant in New York. The tweet, with over 1.2 million views, was misconstrued to mean that vaccinated people were at a higher risk of infection than unvaccinated ones.

The PTI Fact Check desk took an overview of all the information available in the public domain on the XBB.1.5 subvariant.

The World Health Organisation (WHO), in its recent information note on the new sublineage of Omicron, stated that while only minimal data was available on XBB.1.5, the subvariant had a "growth advantage compared to other circulating Omicron sublineages and may contribute to an increase in cases globally".

Citing Centres for Disease Control and Prevention data, a Reuters report dated January 20 stated that the Omicron XBB.1.5 subvariant was estimated to account for nearly half of the COVID-19 cases reported in the United States to date.

The desk also scanned Google for data or reports on the effectiveness of COVID-19 vaccines and checked what global health agencies had to say about the possibility of vaccination increasing the risk of infection or reinfection.

The WHO website clearly states that COVID-19 vaccines are "very effective at preventing serious illness, hospitalisation, and death from all current virus variants".

It also stated that while the vaccines reduce the risk of developing severe illness and death, "no vaccine is 100 per cent effective". "A small percentage of people will still get ill from COVID-19 even though they have been vaccinated," it added.

The fact check team searched for the US' COVID-19 vaccination figures to understand what percentage of the population has received single or both doses to date. Finding this data was necessary because the claim raised questions about the effectiveness of the vaccines.

According to the 'Our World in Data' website, 69 per cent of the overall population of the US had been fully vaccinated till January 17, while 12 per cent had been partially vaccinated. This means that 81 per cent of the total population has been wholly or partially vaccinated.

In terms of numbers, 229.51 million people were vaccinated entirely, while another 39.26 million were partially vaccinated till January 17.

With the data suggesting that over 80 per cent of the US population is vaccinated and the WHO affirming chances of reinfection in vaccinated people, it would be imperative to say that the claim made in the tweet was not a revelation.

Since a significant part of the population is vaccinated against the virus, several cases of reinfection will also be from those who have received the jab.

Dr Rajib Dasgupta, Professor, Centre of Social Medicine and Community Health at Jawaharlal Nehru University, told PTI that XBB.1.5 is the "most transmissible subvariant" and has extensive "immune-escape properties".

"The statement (claim in the tweet) made is what, in epidemiological terms, is referred to as spurious association. This is assuming no other motivation for a statement such as this. As most of the population gets vaccinated, most cases will be among the vaccinated group.

"XBB.1.5 is the most transmissible subvariant detected yet and has emerged as the dominant variant in the northeastern states/parts of the USA. It has immense immune-escape properties and is therefore infecting large numbers, including those previously vaccinated and those who had Covid earlier," he said.

Dr N K Arora, Chairman of India's COVID-19 Working Group of the National Technical Advisory Group on Immunisation (NTAGI), said the infection rate in the case of XBB.1.5 in a country depends on the vaccination status and the hybrid immunity of the community.

"Local epidemiology is more important. Today, the important point is whether any virus is associated with severe disease, hospitalisation or death in a particular context. Fortunately for India, the number of cases is hovering around 150 per day with practically no hospitalisation and death. Many of these sub-variants, which are circulating in higher proportions in other countries, have not been able to expand similarly within the Indian context," Arora told PTI.

Hence, there is no conclusive evidence to support the claim that those vaccinated are at a higher risk of getting infected with the XBB.1.5 subvariant.

The fact check team concluded that the tweet by the NYC Health Department was taken out of context.

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