Tuesday, 16 February 2021

"Why did COVID fail to take off in India and has now collapsed?"

A good article in The Daily Mail (whose covid-19 related reporting has been very good):

Scientists are baffled by the relatively low rate of coronavirus infections in India after at one point it looked as though it might surpass the US as the country with the biggest case toll.

Infections began to plummet in September, and now the country is reporting about 11,000 new cases a day, compared to a peak of nearly 100,000, leaving experts perplexed.

They have suggested many possible explanations for the sudden drop, seen in almost every region, including that some areas of the country may have reached herd immunity or that Indians may have some preexisting protection from the virus.

I had noticed that, and I am as baffled as they are. As the charts in the article show, India had a steady increases in cases/deaths for a few months, followed by an equally steady decline. Peak daily deaths were no higher in India than in the UK, even though India's population is twenty times as large. There was no exponential growth or fall, it's a straight line up and a straight line back down.

Brazil had been following a similar straight up and down path to India until late last year, when they were hit by a second wave and/or the Brazil variant. But India is approx. one-fifth of the world population, so you've expect there to have been a far few new variants there as well.

Answers on a postcard, your guess is as good as mine.

Something else that baffles me is that the lockdowns/easing don't seem to have had any discernible impact on daily UK cases/deaths. The easing of the first lockdown in July (in the middle of a gloriously warm summer) had no discernible impact - there was no sudden increase. Numbers didn't start ticking up until two months later (when it started getting cold).

They peaked and started falling again just before the December lockdown, and they peaked again two months after that. In other words, the number of infections continued going up for nearly two months after the lockdown started. Of course we'll never know what would have happened without lockdowns, but hey.
Also, well said Mr Z. From the BBC:

Vaccine Minister Nadhim Zahawi said that it's his "very strong instinct... to say, those who through no fault of their own other than their work, have to come into contact with the virus, should be prioritised". He listed shopkeepers, teachers and police officers as those who might be prioritised next.

Yup, give the teachers a jab and let's get the kids back to school ASAP. I trust that bus drivers are also in his list.


ontheotherhand said...

There's an article in The Spectator explaining the survival of the fittest evolution of diseases. Cough/sneeze spread disease strains are in a competition to see which can successfully infect the most people, and the winning variant is typically that which gives mild symptoms to keep you walking around, and is easily transmitted. On the other hand mosquito or water transmitted diseases want you immobile with a high viral load, filling mosquitos and sewers. The Indians perhaps have let the mild version win? Whereas when we lock down and take people to hospital, we become the mosquitos selecting the sickest only and keeping them all in one place in care homes and hospitals?

Mark Wadsworth said...

OTOH "The Indians perhaps have let the mild version win?"

I watched a programme about Spanish Flu that said the same thing (I think). At first, everybody had the mild strain and went round infecting each other quite happily. Then they decided to stick all mild cases in hospital or quarantine, only then did the really bad strain catch hold. Or something like that.

ontheotherhand said...

The other way Mark. It's in the Spectator article. The army's extraction of the sickest, and then transporting them on stretchers, made them the mosquitoes.

DCBain said...

In the same way that wuflu can tell the time and follow guvmint orders, it doesn't like curry . . .

Sobers said...

I'm pretty convinced that the variation in how severe a country has been affected by CV will eventually be explained by fixed factors such as genetics, weather/climate and societal characteristics (ie age structure/general health level/smoking prevalence). My feeling is that very little of the government imposed controls will have had much effect overall, except in the cases of countries that can (and did) seal their borders before getting many cases, such as NZ and Taiwan.

With regards to competing versions of the virus, I have read a suggestion that the vaccines could make more virulent strains of the virus more viable. Natural selection in virus mutation normally means that more infectious but weaker strains tend to out compete more virulent strains, because the virulent ones kill their hosts quicker and thus are spread less. And thus weaker strains become the dominant ones. However the vaccines we are being given do not prevent infection, or indeed onward transmission, they just reduce the symptoms to manageable levels. Thus if a vaccine prevents the virulent strain from dying out (as it reduces the victim's symptoms and allows them to spread it more) then a more virulent strain could become the dominant strain. Which would be bad news for the proportion of the population who have not had, or cannot have the vaccine. Plus anyone in other countries who has not been vaccinated where it might travel to.

Mark Wadsworth said...

OTOH, I remembered it and explained it all wrong. Agreed.

DCB, that's seems as likely as all the other explanations. Curry is a good disinfectant/food preservative.

S, I don't think it will ever be explained. Look at cases per capita in European countries, they can be twice or four times as much in one country as in a neighbouring - and otherwise similar - country. I wish it could be explained but I'm not hopeful.

Re vaccines, yes, that is a worry, but needs must.

John Arthur said...

Perhaps the Indians get enough Vitamin D from sunlight.

Andrew S. Mooney said...

One idea might be that most of India's population is still rural, and with the cities locked down, they are isolated. Additionally the Indian police have actually been enforcing the policy, and by "enforcing" I mean getting the sticks and batons out. Enter "Indian Police curfew kick ass" on youtube and what you don't find hilarious is simply terrifying.

Mark Wadsworth said...

JA, that's a possible, but jars with Brazil. Also, they tend to cover their skin, which largely cancels out the extra sunshine.

ASM, some sources say that the Indian lockdown is only observed half heartedly. Others say what you say. Even in rural areas, they have local markets etc where lots of people gather. So all plausible, but not really conclusive either way.

Sobers said...

I bet there's not much obesity and type 2 diabetes in India though. Even among the elderly. I reckon thats going to be one of the critical factors - the level of fitness among the broad mass of the population. We all know the West in general is going through a diabetes epidemic (mainly IMO due to the medical profession having fallen for the Ancel Keyes lie 'saturated fat bad/carbohydrates good') and that is what is driving the CV deaths among the middle aged and even younger age ranges - we are all far too fat and unfit. Combine the two factors (the far older age structure of the UK population and the obesity/type 2 prevalence) and that will account for why poor countries like India (and many African ones) have been largely unaffected by CV and the West has been hit hard.

Mark Wadsworth said...

S, again, that all sounds plausible to me, but I'm sure I could scratch round and find counter-examples or find random articles saying that Indians are just as fat as everybody else, e.g. this https://en.wikipedia.org/wiki/Obesity_in_India.

Bayard said...

Mark, perhaps the Veganistas are right and it's to do with meat eating. That would account for the Indian and Japanese data and why the West has got it worse than the East.

Mark Wadsworth said...

B, there was something about vegetarians being less affected.