“Covid Infections Plateauing but Need to be Observed Closely:” Govt

NEW DELHI, Jan 27: Noting that about 400 districts have logged weekly COVID positivity rate of over 10 per cent, the union government on Thursday said the trend needed to be observed closely though early indications of Covid infections plateauing have been reported in some places.

Stressing the need to continue with precautions to curb the surge in infections, it noted that Karnataka, Kerala, Tamil Nadu, Gujarat, Andhra Pradesh, Rajasthan were recording a high number of COVID-19 cases. However, a decrease in COVID cases and positivity rate have been observed in Maharashtra, Uttar Pradesh, Delhi, Odisha, Haryana and West Bengal, the government stated.

Addressing a press conference in New Delhi, Lav Agarwal, the joint secretary in the Health Ministry said, “A clear trend in terms of fewer COVID cases requiring oxygen-supported beds or ICU beds has been observed. Also, active COVID-19 cases and corresponding deaths are much lower during the present wave compared to earlier surges,” he said.

Warning against any lax in observing COVID-appropriate behaviour, Agarwal said 400 districts have reported over 10 per cent weekly COVID positivity while in 141 districts it was between five to 10% in the week ending January 26. About the prevalence of the Omicron variant of coronavirus in India, he said, 1,292 cases of the latest variant of concern were found on genome sequencing in December which rose to 9,672 in January.

The top 10 states in terms of active Covid cases were contributing over 77% of total active infections in the country, Agarwal said, adding 11 states have over 50,000 active Covid cases while Karnataka, Maharashtra and Kerala have over 3 lakh active infections.

In response to a question, he said, “Early indications of COVID cases plateauing have been reported in some places but the trend needs to be observed and precautions need to be continued.” About the vaccine coverage, the press conference was informed that 97.03 lakh healthcare, frontline workers and comorbid people aged 60 and above have been given the precaution dose of COVID vaccine.

Also, 59% of adolescents in the 15-18 year age group have so far received the first dose of COVID-19 vaccine. The health ministry stressed that vaccination is providing support in terms of fewer cases, fewer hospitalizations and less severity in COVID-19 cases.

In the last couple of weeks, there has been a noticeable increase in the discovery of BA.2 sub-variant of Omicron from several countries, leading to fresh worries about the possibility of another surge in cases. Last week, the UK Health Security Agency flagged this sub-variant and designated it as a “variant under investigation.” In its latest weekly bulletin, the World Health Organisation noted that a number of countries had reported an increase in the BA.2 sub-variant in the last seven days.

This sub-variant has been present in substantial numbers in India as well, but India is not amongst the countries where the recent increase has been noticed. The BA.2 could possibly be more infectious than the more commonly found BA.1 variety but there is no evidence to suggest that it is more harmful.

BA.2 is one of the several sub-variants of the Omicron which has spread rapidly across the world since November. The Omicron name was given to the B.1.1.529 lineage after it was designated as a variant of concern. Later, it was found that this lineage had small variations of its own, and the three most common were named B.1.1.529.1, B.1.1.529.2, and B.1.1.529.3. For ease of reference, however, these sub-lineages were later re-classified as BA.1, BA.2 and BA.3.

The Omicron sub-variant that has been most common in circulation till now is BA.1. This continues to be the case even now, though the proportion of BA.2 is on the rise. According to the WHO, 98.8 per cent of all Omicron genetic sequences submitted in global databases till January 25 were that of BA.1 variety. BA.2 retains most of the characteristics of BA.1 but has some more mutations that can give it a distinctive characteristic.

“…the BA.2 descendent lineage, which differs from BA.1 in some of the mutations, including in the spike protein, is increasing in many countries. Investigations into the characteristics of BA.2, including immune escape properties and virulence, should be prioritised independently (and comparatively) to BA.1,” the WHO has said.

So far, studies have not showed any distinct advantage of BA.2 over BA.1, particularly in the nature of disease that they cause, but the recent rise in BA.2 cases is likely to put a more intense spotlight on this sub-variant.

The increase in proportion of the BA.2 has been noticed mainly in Europe, most prominently in Denmark, where over 8,300 genetic sequences of this Omicron sub-variant have been identified so far. In fact, in Denmark, BA.2 now comprises almost half of all Omicron cases. The United Kingdom has found 607 samples with this sub-variant, while India has discovered 711 till now. The other countries where BA.2 has been found in abundance are the United States, Norway, Sweden and Singapore.

According to the outbreak.info website, that tracks the prevalence of the different lineages of this virus across the world, BA.2 has so far been discovered in 49 countries. The BA.2 sub-variant is known to be more transmissible than the BA.1 variety, which could possibly explain its surge in recent days. But as of now, researchers have not noticed any difference in the nature of disease that it causes.

Though these are sister lineages, there are important genetic differences between BA.1 and BA.2. In fact, Statens Serum Institute, Denmark’s main institution on infection diseases, said the difference between BA.1 and BA.2 was greater than the difference between the original Wuhan variant which started the epidemic and the Alpha variant, the first major variant that had become dominant in 2020.

“Such differences can lead to different properties, for instance concerning infectiousness, vaccine efficiency or severity. So far, there is no information as to whether BA.1 and BA.2 have different properties…,” the institute said in a note last week.

“Initial analysis shows no differences in hospitalisations for BA.2 compared to BA.1. Analyses regarding infectiousness and vaccine efficiency etc. are ongoing, including attempts to cultivate BA.2 in order to perform antibody neutralization studies. It is expected that vaccines also have an effect against severe illness upon BA.2 infection,” the note said.

(Manas Dasgupta)