The timing: increase in cases, waning vaccine effect, fears of Omicron
The eagerly awaited decision of provide additional doses of vaccine came when the number of Covid cases, after a five-month drop, began to rise in some states, apparently fueled by the Omicron variant.
The latest data show that the reproduction number R, a measure of how quickly the disease is spreading, has crossed the value of 1 in several states, after which a threshold of cases begin to increase rapidly.
The decision was due anyway, even though there was no threat from Omicron. In the United States and Europe, booster doses began long before the emergence of Omicron, after most of the eligible adult population had been fully immunized.
India is now at a similar stage, with over 60 percent of the eligible population fully vaccinated and over 90 percent of them having received at least one dose.
There is more and more evidence to show that immunity generated by vaccines drastically reduces after eight to nine months, requiring a new round of vaccinations to prevent serious illness and death. Thus, those who received their second doses before April, mostly nursing staff and the elderly, could therefore benefit from booster doses.
The Omicron threat isn’t out of the equation either.
For about a week, some states show signs of Covid resurgence, mainly Delhi, Maharashtra, Gujarat and Karnataka. Major cities like Delhi, Chennai, Mumbai, Kolkata, Bengaluru and Pune also show a similar trend.
The latest data from a team of researchers from the Institute of Mathematical Sciences in Chennai shows that the R-value, an estimate of the average number of people to whom the infection is transmitted from someone already infected, was now above 1 in Maharashtra.
Delhi crossed 1 days ago and is now joined by Bengaluru and Kolkata, according to Sitabhra Sinha, the lead researcher.
For India as a whole, the R-value is still less than 1, but it shows signs of increasing. An outbreak is not to be ruled out. This would hardly be surprising given that more than 600 Omicron infections have been confirmed in the country.
Considering that only a fraction of positive cases are confirmed as Omicron infections due to the need for genome sequencing results, the actual spread of the Omicron variant in the population could be several times higher.
And as countries like the US, UK and several others in Europe show, the Omicron variant is spreading at a much faster rate, even infecting previously infected, fully vaccinated people or children.
In the past four days now, the UK has reported a record high number of new cases – with 1.7 lakh of cases detected on Saturday. Before the current outbreak, the number of daily cases had never even approached 1 lakh.
Several other countries in the region, including Spain and France, have detected a record number of cases.
Although the Omicron variant, so far, has been shown to be relatively milder than the Delta at causing serious illness, the large number of infections has the potential to overwhelm hospitals and medical facilities, a situation already experienced by the UK.
In a worst-case scenario, India could experience a similar surge by mid-January or late January. Extra doses of the vaccine can do little to prevent this flare-up if it does occur, but they could be vital in preventing hospitalizations and death.
The same goes for the decision to vaccinate the younger population. Data from Europe shows that a significant number of people infected with the Omicron variant are in the younger age groups who have not been vaccinated.
In fact, in some countries like Spain or Italy, the prevalence of the Omicron variant among young people is almost double that of the general population. Even in India, a significant proportion of people confirmed to be infected with the Omicron variant are under the age of 18 and therefore are not vaccinated.
So getting the 15-18 age group vaccinated from January 3 and revaccinating the elderly and frontline health workers from January 10 could not be more timely.