Let’s prevent Covid surge from becoming a wave

COVID cases have once again started rising in different parts of the country since late February and early March, raising concern about yet another surge. The number of new cases reported daily has gone past 3,000, which is the highest in the last six months, according to the data of the Union Health Ministry. Active cases have consistently risen and are now in excess of 15,000 in the country. The daily positivity rate is 2.73 per cent and the cases are doubling in nearly seven days.

This is also the flu season and new influenza variant H3N2 is on the loose. The symptoms of the two are quite common and overlapping. Many people with flu symptoms are taking it lightly and not getting themselves tested as quickly as they did during the past three years. This may be masking the actual number of positive cases, which may be higher than what are being reported.

Currently, Covid cases are increasing in a few states, including Maharashtra, Kerala, Karnataka, Tamil Nadu, Gujarat, Delhi and Himachal Pradesh. Most of these cases are mild and not resulting in hospitalisation. The majority of the infected people are being treated in home isolation. The few deaths were mostly among the elderly and comorbid patients, even as 14 deaths were reported on March 30.

Experts say that Covid-appropriate behaviour should be practised in public places, including wearing a mask and hand hygiene. One should avoid crowded public places and get vaccinated in order to contain the rise in cases. People should get themselves tested if they have flu-like symptoms, isolate themselves if they test positive and get proper treatment from a qualified doctor.

The governments are on the alert; high-level meetings, preparedness drives and mock drills are being conducted and advisories are being issued to stop the rapid spread of the virus. The Health Ministry and the Indian Council of Medical Research (ICMR) recently issued an advisory to all states to maintain an optimum level of testing using the RT-PCR method so that new emerging hotspots can be identified in time and corrective measures are taken. The advisory asked the states to strengthen the public health system to contain the surge and assess the preparedness, including the availability of drugs, beds (including lCU beds), medical equipment and oxygen along with the critical human resource.

According to the genome sequencing data available so far, the variant which is showing high prevalence and reportedly driving this surge is XBB.1.16. This variant is a descendant of the recombinant ancestor XBB.1 from which XBB.1.5 variant was derived; the latter caused widespread havoc in China earlier this year. However, XBB.1.5 variant was not a concern in India, barring a few cases reported from here and there.

Little is known as of now about the XBB.1.16 variant except that it contains mutations in the non-spike region of the virus. This region is called ORF9b, which overlaps with a gene that encodes for a viral accessary protein. Not much is known about the implication of this gene and mutations in it but a study published in a journal of medical virology in 2021 had shown that ORF9b negatively regulates host antiviral immunity and, thus, facilitates viral replication. Another study showed that ORF9b binds with a mitochondrial protein Tom70 and blocks its interaction with a heat shock protein Hsp90, which helps SARS-CoV-2 evade the host’s innate immunity. More studies are underway to understand this immune evasion mechanism better.

From the beginning, scientists have made it clear that the virus will keep mutating and churning out new variants. This is the nature of the virus and this is also true of the influenza virus, which comes back in a new form every season, necessitating annual flu shots for the vulnerable population, especially the elderly and the immunocompromised people. Likewise, SARS-CoV-2 virus, which causes Covid, also gets mutated frequently and some of the variants may become a cause for concern, especially if they infect unvaccinated, comorbid, elderly and immunocompromised people. It may be happening at present too that those getting infected are from these groups. Therefore, those who have not taken the shots or the precautionary dose should take it as early as possible.

The need is to collect the data of the people getting infected whether they are vaccinated or not, whether they have had only one shot, two shots or have also taken the booster dose, and if they have any type of comorbidity. This data will help us better understand the pattern of the spread, and whether there is immune evasion as has been reported in the above-mentioned studies.

According to the Vaccinate India dashboard, India has administered more than 2.2 billion doses of approved vaccines so far, which include the first, second and the precautionary dose. About 95 per cent of our eligible population has received at least one dose of the vaccine and 88 per cent is fully vaccinated. This is in addition to the natural exposure during the past Covid waves which provided our population a natural defence in the form of herd and hybrid immunity. According to experts, this protection was not available to the Chinese population due to their ‘zero-Covid’ policy, and that the country experienced a surge in Covid infections and deaths recently due to the XBB.1.5 variant.

At present, we have a good network of diagnostic laboratories equipped with the RT-PCR facility to test the new cases as they emerge. Added to this is the genome-sequencing centres that can identify the new strains. We also have a robust surveillance system and data is reported in real time to estimate any outbreak. This, along with the experience that we have had during the past waves of Covid, will come in handy to contain the new surge. Preparedness of our hospitals with the required logistics and experience of our medical and paramedical staff of handling mild, moderate and severe cases of Covid inspire confidence about handling the surge much better than ever.

Having said that, no stone should be left unturned to avoid the infection in the first place and prevent the surge from turning into a wave. Covid-appropriate behaviour is the most effective way to prevent the spread of viruses, be it the coronavirus or the current seasonal influenza (H3N2) virus.