By Dr T Jacob John & Dr M S Seshadri
The newest SARS-CoV-2 variant that may upset the relatively steady state of the present endemic prevalence of the Delta variant in India is the B.1.1.529, named Omicron by the WHO.
The variant was detected in the second week of November in South Africa. Since then, it has been detected in Israel, Belgium, Hong Kong, the UK, Australia, Denmark, Holland, and Italy.
The Omicron variant has over 30 mutations in the spike protein region that seem to confer two properties that render it worse than Delta. One, it is characterized by a very high viral load in infected people and consequently spreads faster.
Second, it infects people with vaccine-induced immunity that protects against other variants. However, these preliminary assessments await confirmation.
Unless we take immediate and important interventions, it can invade us very fast, with possible dire consequences. Omicron does not seem to cause more severe disease than earlier variants, but it is too soon to be sure.
Our first defense is to prevent the importation of the Omicron variant. The plan is to introduce strict screening of air passengers from December 1. Air travelers arriving in India may be classified into three categories. All arrivals from the cluster of countries in Southern Africa are the first category. They must be subjected to the RT-PCR test on arrival, kept under strict quarantine for 72 hours, retested, and released only if negative.
The second test on the third day will detect those who had been infected but were tested too early and detection was missed. This would ensure that the inconvenience to uninfected travelers will be minimized to just three days. Those who are infected must stay in quarantine until their RT-PCR test turns negative.
The second category should consist of all travelers from other countries known to have been infected by Omicron. The passengers must be tested on arrival and let free if negative with strict instructions for Covid-appropriate behavior and a proviso that they will get retested three to four days later.
Those from non-infected countries constitute the third category. They carry none or minimal risk for Omicron importation and restrictions are unfair at this point. The current method of airport checking should be sufficient for now.
INSACOG, a consortium of 28 national laboratories to monitor the genomic variations in SARS-CoV-2, must ensure that all RT-PCR tests done in India will reliably detect the Omicron variant.
For achieving high-immunity levels, the current two-dose schedule should be followed by a booster dose after a minimum of six months.
So, our defense strategy calls for vaccinating all, including children, with two doses followed by booster doses after six months. (The New Indian Express)