CoronaVac Letting Chile Down

[Lonnie]

CoronaVac Letting Chile Down

A study published by the University of Chile earlier this month reported that CoronaVac was 56.5% effective two weeks after the second doses were administered in the country. Crucially, however, they also reported that one dose was only 3% effective.

It comes after the head of China’s Centre for Disease Control and Prevention said earlier this month that China may need to replace its Covid vaccines or change the way they are administered in order to make them sufficiently effective.“We will solve the problem that current vaccines don’t have very high protection rates,” George Gao, director general of the Chinese CDC, said at a conference on April 11

LONDON — Chile’s vaccination campaign against the coronavirus has been one of the world’s quickest and most extensive, but a recent surge in infections has sparked concern beyond its borders.

Almost 40% of the South American country’s total population have now received at least one dose of a Covid-19 vaccine, according to statistics compiled by Our World in Data, reflecting one of the highest vaccination rates in the world.

 

Only Israel and the U.K., respectively, have inoculated a larger share of their population with at least one dose.

Nonetheless, Chile has endured a sharp uptick in coronavirus infections in recent weeks, even with its world-renowned vaccine rollout and strict lockdowns in place for much of its 19 million inhabitants.

The Pan American Health Organization’s regional director has since emphasized that for most countries in the region, vaccines won’t be enough to prevent rising infection rates.

The number of daily cases in Chile rose to a record high on April 9, climbing above 9,000 for the first time since the pandemic began and significantly higher than the peak of almost 7,000 recorded last summer.

What has gone wrong?

Health experts say the country’s latest surge in cases has, in part, been driven by more virulent strains of the virus, a relaxation of public health measures, increased mobility and defiance of simple precautions — such as physical distancing and wearing a mask.

Chile’s center-right government, led by President Sebastian Pinera, had ordered the closure of the country’s borders from March to November of 2020, albeit with a few exceptions, before the decision was taken to reopen them to international passengers late last year.

Shops, restaurants and some holiday resorts were also opened in a bid to boost the country’s pandemic-stricken economy.

Yet, while the country’s vaccination rollout powered ahead of most, the spread of a more virulent strain of the virus — such as the P.1 variant, first discovered in travelers from Brazil — has led to a substantial rise in cases.

There have also been questions raised about vaccine efficacy, given Chile’s widespread use of CoronaVac, the coronavirus vaccine manufactured by Chinese firm Sinovac.

It comes after the head of China’s Centre for Disease Control and Prevention said earlier this month that China may need to replace its Covid vaccines or change the way they are administered in order to make them sufficiently effective.

“We will solve the problem that current vaccines don’t have very high protection rates,” George Gao, director general of the Chinese CDC, said at a conference on April 11. He has since told state media that his comments were misunderstood.

Late-stage data of China’s Covid vaccines remain unpublished, and available data of the CoronaVac vaccine is varied. Brazilian trials found the vaccine to be just over 50% effective, significantly less effective than the likes of Pfizer-BioNTech, Moderna and Oxford-AstraZeneca, while Turkish researchers have reported efficacy as high as 83.5%.

A study published by the University of Chile earlier this month reported that CoronaVac was 56.5% effective two weeks after the second doses were administered in the country. Crucially, however, they also reported that one dose was only 3% effective.

“This would help to explain why Chile — with one of the world’s most robust vaccine rollouts but 93% of the doses coming from China — has experienced a simultaneous significant expansion in cases, and a much slower decline in hospitalizations and deaths compared to the early rollouts in Israel, the United Kingdom and the United States,” Ian Bremmer, president of risk consultancy Eurasia Group, said in a research note.

“Chile and the United Arab Emirates are both considering implementing a third dose (so a second booster shot) of the Chinese vaccine accordingly; a change in communications that will increase vaccine hesitancy for the Chinese vaccines more broadly,” Bremmer said.

‘Comprehensive strategies’

“I cannot stress this enough — for most countries, vaccines are not going to stop this wave of the pandemic,” Carissa Etienne, director of PAHO, said during a weekly press briefing on Wednesday. “There are simply not enough of them available to protect everyone in the countries at greatest risk.”

Etienne pressed policymakers in the region to implement “comprehensive strategies” to speed up the rollout of vaccines and stop transmission by using proven public health measures.

On April 14, the Americas reported more than 1.3 million Covid infections and nearly 36,000 deaths in the past week, according to data compiled by the United Nations health agency.

To date, the Americas has recorded 58.8 million cases and more than 1.4 million deaths, making it the worst-affected region in the world.

“We are not acting like a region in the midst of a worsening outbreak,” PAHO’s Etienne said, describing South America as the “epicenter” of the virus.

In addition to relaxed restrictions in some areas, Etienne said new and highly transmissible variants of the virus had prompted a steep acceleration of cases. At present, Brazil, Colombia, Venezuela, Peru, and some areas of Bolivia are reporting a sharp uptick in infections.

Paraguay, Uruguay, Argentina and Chile are also experiencing a continuing increase in Covid cases, Etienne said.

https://www.cnbc.com/2021/04/19/covid-chiles-coronavirus-cases-hit-record-levels-despite-vaccine-rollout.html

 

 

 

[Riobard]

Things move quickly. That report is already outdated. Here are the recently updated data. ‘Partial’ means prior to second dose of CoronaVac. The counterintuitive rise in case incidence is an artefact of reckless behaviour, among the approximately half of population not yet fully inoculated; and for those vaxx’d, with the standard period required for individual immunity buildup following inoculation not yet achieved, in context of more contagious P1 variant. Otherwise, CoronaVac is having a positive impact, poses minimal adverse events, and is welcomed by the people. CoronaVac was never intended to be single (partial) dosing. The results underscore that the full dose cycle is imperative.

[Similarly, complete municipal vaccination of Serrana using CoronaVac, SP, BRZ is yielding dramatically beneficial results]
[The article uses the term ‘the Chinese vaccine’, conflating Sinovac’s CoronaVac with another company’s product, that of Sinopharm, being utilized and now manufactured in UAE.]

CHILE:

[Lonnie]

30 minutes ago, Riobard said:

That report is already outdated

Well that's good news though I believe your chart shows rather high symptomatic and death rates.

 

[Riobard]

1 hour ago, Lonnie said:

Well that's good news though I believe your chart shows rather high symptomatic and death rates.

 

They are not incidence rates. They represent the amount of reduction in incidence for the vaccinated compared to the non-vaccinated for millions vaccinated thru Feb and Mar. Effectiveness is a calculation much like efficacy, the latter in a controlled research trial, the former applied in the real world setting. 

If somebody showed you these metrics and you were asked to try to explain the differences in incidence (per 100K population) between Chile and Brazil, without knowing their vaccination status history, it would be reasonable to assume that Chile had a far more advanced vaccination campaign because the new case incidence is similar but reduced mortality, a primary desired endpoint of inoculation, is quite pronounced for Chile. It is about half, two-fifths that of Brazil, with almost identical current infection case incidence trend. Brazil’s and Chile’s case fatality rate historically tracked similarly to their respective incidence rates but now Chile’s mortality relative to case incidence is considerably lessening. These are more crude comparisons that corroborate more systematic epidemiological research. 
 

[unicorn]

It looks as though whatever vaccine Chile's using, it's not as effective as Pfizer, Moderna, A-Z, or J&J. 

[Riobard]

2 hours ago, unicorn said:

It looks as though whatever vaccine Chile's using, it's not as effective as Pfizer, Moderna, A-Z, or J&J. 

It is, obviously, but we are at this juncture dealing with the bigger picture globally. I think that most people by now are aware how 67% effectiveness stands up compared to 90+%. And that if you can snag a product of that lower efficacy caliber purely in terms of its capacity for case and severity reduction when nothing else is available you take it. Low levels of vaccination hesitancy somewhat compensate for lesser efficacy, as does the ability to avoid delays in follow-up booster doses within the initial vaccination cycle. 

Chile is using as much of 3 of the vaccines you listed as it can get. Should it have waited to administer approximately 90% of vaccinations, the percentage attributable to CoronaVac given over the past few months, and substituted them with products with greater than 67% effectiveness yet some with complex cold-chain logistics, whenever they trickled in over their Autumn, trading off lives for snubbing a product that is now showing well above the threshold of efficacy for authorization? I don’t think so.

I believe the take-home is that you need vast inoculation uptake, combined with their approximate existing 20% natural immunity within the population, in order to see results, outcomes that are likely already unfortunately compromised by immunity-escape and more contagious variants.

Chile also tests at quite a high level, so the average true degree of case severity decreasing is not necessarily reflected in rolling new case incidence; reduced hospitalization and mortality is essentially a surrogate marker for vaccination apparently reducing symptom burden. Moreover, vaccine effectiveness calculations are often artificially lowered by relatively high levels of natural immunity in the population, as is the Chilean case. The true effectiveness is probably better than the recent 67% reported. Similarly, CoronaVac effectiveness is a metric comparing infection case variables between those inoculated, and not, with CoronaVac. Since close to 5% of the population not vaccinated with CoronaVac is partially or fully vaccinated with products clinically higher in efficacy rankings, the true effectiveness of CoronaVac in isolation  is, again, artificially deflated because the two groupings do not start off with the same proportions of baseline immunity.

[spoon]

6 hours ago, unicorn said:

It looks as though whatever vaccine Chile's using, it's not as effective as Pfizer, Moderna, A-Z, or J&J. 

If only these more effective vaccine is produced massively and equally distributed to these countries who have to settle with the less effective option. But of course, those vaccines were hogged by developed countries. I agree totally that anything that pass WHO criteria of 50% effectiveness will still save lives and warrant the usage, especially at a time where we cant afford the luxury of choosing which vaccine we can use. The more concerning issue is vaccine acceptance in some countries where the gov arent bold enough to make it compulsory. Sadly, thats include my country, where the current drive for vaccine registration are 37% only. I wish our gov would just make this compulsory. 

[vinapu]

1 hour ago, spoon said:

 I wish our gov would just make this compulsory. 

I'm vaccines enthusiast myself and took my first shot already but making it compulsory for the whole population for relatively untested products would be risky at this stage