IS SINOVAC EFFECTIVE?

With the concern about the efficacy of vaccines being questioned, the timing of the medical worker outbreak in Indonesia raises valid concerns. Hundreds of health workers were said to have been infected after being given complete doses of Sinovac, a biopharmaceutical company. Some patients were hospitalized with decreasing oxygen saturation levels, which indicate a serious condition.

There are a few issues that need to be addressed in this latest outbreak. Let us try to look at them and see if we can find the answers based on the information available.

First, the World Health Organization (WHO) approved emergency use of Sinovac's vaccine as it showed at least 51% of recipients benefitted from having less severe COVID-19 symptoms, leading to less hospital stays. None of the tested patients were hospitalized for COVID-19. However, this puts into question the strain of COVID-19 that was tested in this study.

The Delta Variant, first detected in India in October 2020, poses the greatest concern, as it is said to be driving the current outbreak. This variant shows increased transmissibility and virulence. It is feared that the Sinovac vaccine is ineffective against this strain. However, there is a need to do further studies on this. Nothing is conclusive.

The second issue involves the decreased vigilance among the populace. Some of those given the full dose of the vaccine mistakenly believe that they are now immune to the disease, so they become less careful. This includes the health workers who were among the first to be vaccinated. During public holidays, the increased movement of people becomes a risk for transmission.

What is important, however, is that we follow safety protocols. Being fully vaccinated is not a license for us to lower our guard. We must still wear masks when we go outside until we are able to control the spread of this menace.

Why are there different COVID-19 strains?

Just like most living organisms, adaptive mechanisms enable us to survive in adverse conditions. For viruses, mutation is the mechanism to improve “survival” even though they cannot replicate outside a living cell – or outside the human body. Viruses are known to mutate easily. This enables them to “escape” destruction and identification by the immune system. The changes in their structure leads to the development of different COVID-19 strains. When a virus is spreading, the likelihood of the virus mutating increases. The more opportunities a virus has to spread, the more it replicates.

Some strains can still be neutralized by the currently available vaccines.  This has been proven in studies that came out this year.

According to the World Health Organization, the COVID-19 vaccines that are currently available are expected to provide at least some protection against new virus variants. This is because these vaccines elicit a broad immune response involving a range of antibodies and cells – meaning the mutants will still be neutralized by the drugs.  Alterations in the structure of the virus should not make vaccines completely ineffective. In the event that any of these vaccines prove to be less effective against one or more variants, it will be possible to change the composition of the vaccines to protect against these variants.

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Should we avoid Sinovac because of this?

The simple answer is no. Science has proven the effectivity of the vaccine, despite the recent news articles stating otherwise. It is understandable to have certain apprehensions when there are doubts as to the effectiveness of prevention due to outbreaks. However, unless our health authorities say that it is unsafe or ineffective, there is no reason to doubt science. After all, it is science that will enable us to pull through this crisis.