Covid-19 vaccine: Fast action, caution can save lives

Covid 19 vaccine drive
Initial estimates said the new Covid-19 variant has around 70% more transmissibility, but a modelling study published at the end of December puts it at 56%.

Covid-19 vaccine: Everyone is chasing the UK strain now. It started with British Prime Minister Boris Johnson tightening the lockdown followed by health secretary Matt Hancock giving details of how infectious this new variant was. The new strain, B 1.1.7, is the focus of all discussions now.

Initial estimates say the new Covid-19 variant has around 70% more transmissibility, but a modelling study published at the end of December puts it at 56% more than the original strain. It has a total of 23 mutations to its credit and some of them are in the spike protein region, the key with which the virus enters human cells. That makes everyone worried because most vaccines are trying to copy the key to stimulate specific antibodies against the spike protein. If the spikes change too much, the new vaccines may be off target. So far, there is no evidence of this happening, but one never knows what mutations happen next.

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The new Covid-19 strain forced WHO revise the R0 from 1.1 to 1.5 at the end of December. For epidemiologists, this is a huge difference and it means a lot will change on a global scale (more infections, more sick people, more deaths). In simple terms, for 100 infected people, the old strain with R0 of 1.1 would infect another 110 while the new strain would infect 150. So simply put, a difference of 40 more infections per 100 infections. That is massive. Now you know why the UK government has enforced a strict lockdown. Most people are comfortable knowing that the UK strain is just more infectious, and not more lethal. But it could well be a false sense of security.

New Covid-19 strain: A scary prospect ahead

A more lethal Covid-19 strain with R0 of 1.1 is nothing compared to a less lethal one with an R0 of 1.5 when it comes to taking lives. Here is the maths to shake you out of that false security bubble. Assume that the original strain of the coronavirus has an R0 of 1.1 and kills 0.8 people out of every 100 who get sick. In a population of 10,000 people, that virus would kill 129 people in a month. Now imagine two new scenarios, one with a 50% more lethality and another with 50% more transmissibility. The 50% more lethal one would kill approximately 193 people in one month from the 10,000 population. Now guess what is the fatality 50% more transmissible virus can cause.

It’s a shocking figure — 978 people in one month. Simply put, this can kill more than 7 times the number the other one can. This is possible by the rapid multiplication of new cases. Will this happen for sure? No, if there is a change in strategy. To understand this increased transmissibility, one must know how this happens. Nobody is sure as of now, but several suspicions are there. The lead three are (i) increased binding, (ii) increased viral load, (iii) and reduced minimum dose for infection.

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Beat Covid-19 with speed

The good news is that social vaccination methods work well here, even with the B 1.1.7 strain. All that needs to be done is to make it more stringent. Masks all the time, stay away from all crowded places and meet/travel only if absolutely necessary. Work can go on, but fun should wait. Discipline is the only way one that can pull the R.0 down to 1.0 from the 1.5. We need to pull it down quickly before it starts work. People are relaxed that the vaccines are here and the bug is in the bin already. It is not really the case now.

The UK is vaccinating at one tenth of the pace required to beat the bug. So, by the time the vaccines catch up with the required numbers, thousands will fall critically ill and a good number of them will die. So, even the UK needs to step on the gas for the vaccination drive to reduce the damage. The US is doing it even slower than the UK. The fate of slow countries is anybody’s guess. India keeps thinking about a start date. More than a week from ok to jab is slow in Covid-19 terms. A day earlier means many more lives saved.

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So, to sum up, there is a need to go back to the basics because once the new Covid 19 strain settles in a new community, it takes just 4 to 8 weeks for its cult to be in full control. We may see that happening in February. So, what can be a successful plan for India? Just go back to the level of seriousness we showed in the initial months. Use the best masks all the time till two weeks post vaccination. And stay away from the bug till the needle hits the skin.

And for sleeping countries including the poor ones, start vaccinating now and do it as fast as possible. Speed is critical, it will save lives for sure. And the vaccine haters can warm their coffee pots and wait for the new strain.

(Dr Manu Raj is a pediatrician, clinical researcher and research methodologist based in Kochi.)

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Dr Manu Raj is a paediatrician, clinical researcher and research methodologist based in Kochi.