YOURSAY | The debate on Sinovac vaccine's safety and efficacy

 

YOURSAY | 'I would suggest that the Sinovac vaccine be given to all the politicians.'

Deal's off if vaccine doesn't pass muster, KJ assures amid doubts about Sinovac

Enlightened Globalist: Let’s look at the Sinovac study with the details that we have so far:

1. The Phase III trials were done in a hospital setting with a very skewed population of hospital staff.

Firstly, doctors and nurses tend to be in the 20 to 55 age group and the majority would be expected to be healthy. Covid-19 in the study population would be expected to be mild, primarily because of the younger age and absence of co-morbid conditions.

2. There’s nothing wrong with selecting the study population, except that the results cannot be extrapolated to the rest of the population, especially the elderly and those with health conditions like diabetes and heart disease.

3. That it only protected 50.4 percent of the population is poor, as the minimum before any vaccine can be approved is 50 percent protection. This figure appears to be the worst among all vaccines that have been reported so far regarding vaccine efficacy. It will take a much longer time to reach herd immunity with a 50 percent protection rate.

4. Publishing the study in an internationally peer-reviewed journal is important. We can rant about these journals being pro-Western, but the reality is that almost all countries in the world (with the probable exception of China and Russia) still regard The Lancet and The New England Journal of Medicine as the gold standard for medical journals.

The standard practice before a vaccine is approved is that:

1. Phase III studies should be in a population that mirrors the population to be vaccinated. The Pfizer, Moderna and Oxford vaccines tried to mimic the general population of adults as far as possible, including pre-morbid conditions. Children were excluded for obvious reasons.

2. The studies were published in peer-reviewed medical journals.

3. Programmes to vaccinate the population only started after Phase III trials were completed, unlike the Russian and Chinese vaccines. What the Chinese and Russians did is against the generally accepted international norm regarding vaccine administration.

I am presenting my observations from a purely scientific angle, without being biased towards any country or region. Until we get further data, we should be cautious before approving the Sinovac vaccine in Malaysia.

WeeChat: Sinovac's Covid-19 vaccine is 100 percent effective in preventing severe and moderate infections, 77.96 per cent effective in preventing mild cases.

Experts say the result is good enough considering almost all participants in Brazil are high-risk medical workers, and the 77.96 percent efficacy for mild-case protection means the vaccine can reduce 78 percent of people from needing hospitalisation.

But many Western media refused or omit crucial information and will highlight figures to compare the different vaccines when they are not relevant.

For example, Sinovac in Brazil mainly uses participants who are high-risk medical workers who are exposed to the virus every minute of every day for months.

Whereas the Western vaccines use participants who are ordinary public not in high-risk professions and by comparing the efficacy, this will give a very skewed impression, which is precisely how the Western media are good at - hidden hands to smear and put their own brands ahead.

Caripasal: Yes, it is very important to understand that the protection rate of a vaccine in a trial is not solely dependent on the overall efficacy, but also the infection risk of the volunteers throughout the trial.

The risk of those volunteers getting the infection will be automatically higher if they are living or working in an ultra-high-risk environment, thus dragging down the overall efficacy of the vaccine.

In Brazil, Sinovac conducted their Phase III trial almost only on medical workers, ie those who have the highest risk of being infected. This is the only Phase III trial conducted solely on the medical workers.

Pfizer and Moderna, on the other hand, recruited their volunteers mainly from the general population, thus the risk of their volunteers being infected after the vaccination is relatively lower, resulting in higher overall efficacy in their Phase III trials.

In addition, in the subgroup analysis, Sinovac showed an extremely high protective effect against serious Covid-19 complications.

ScarletBeetle0653: For those who do not understand what a Phase III trial is (you do not preselect anyone for the trial):

Phase III trials compare a new drug to the standard-of-care drug. These trials assess the side effects of each drug and which drug works better.

These trials are randomised. This means that patients are put into a treatment group, called trial arms, by chance. Randomisation is needed to make sure that the people in all trial arms are alike.

This lets scientists know that the results of the clinical trial are due to the treatment and not differences among the groups. A computer programme is often used to randomly assign people to the trial arms.

There can be more than two treatment groups in Phase III trials. The control group gets the standard-of-care treatment. The other groups get a new treatment. Neither you nor your doctor can choose your group. You will also not know which group you’re in until the trial is over.

With that being said, the Phase III trial results for Pfizer, Moderna and Oxford vaccines are published and peer-reviewed by experts around the world.

The Sinovac vaccine data, however, are still being kept a secret despite all the trials being done. For those who have been touting so much about the Sinovac vaccine without the peer-reviewed Phase III data and report, they can get vaccinated and possibly get infected in the future.

Let the data do the talking. At least, I know that I will be safe when I am inoculated with vaccines with proven good efficacies.

Even if this vaccine is given to us free, I would not want to have it as there is a 50 percent chance that I may still get infected. I would not want to take this risk and endanger the lives of my families or friends.

Since Science, Technology and Innovation Minister Khairy Jamaluddin and those who signed the contract with Sinovac are so sure of the vaccine, I would suggest that the Sinovac vaccine be given to all the politicians.

For the rest of the rakyat, give them the only Pfizer or Moderna vaccines.

Hmmmmmmmm: After reading through the comments, I think it is safer to try Sinovac as they are using the traditional way of immunisation, ie using weakened viruses to stimulate our response system whereas the others are using modified RNA, which is a new technology for which long-term side effects are still unknown.

I am guessing that these vaccinations are not a once-off thing and may need to be done at a regular interval.

If Sinovac doesn't work well while other vaccines turn out to be better, we can always change further down the line.

Whereas if we were to start with say, Pfizer, and it gives severe side effects one year down the line, will we be able to reverse the side effects?

Or is there such a thing as if we don't have any side effects after say one year, then there is no possibility that any side effects will appear after that? There are so many things to ponder. - Mkini