BioNTech or Sinovac: Which is the best vaccine for COVID-19?

Written by Dr David Owens

The short answer is that both vaccines are very good at preventing death and serious illness. However, we now have very good evidence that of the vaccines available in Hong Kong, BioNTech is significantly more effective. In Hong Kong, we have one good vaccine and one outstanding vaccine. This statement is not in any way a criticism of Sinovac and is based exclusively on evolving science. We encourage everyone to be vaccinated with the vaccine of their choice.

COVID-19 has resulted in an ’infodemic’ which has been subject to both misinformation and disinformation. Hong Kong continues to have high levels of vaccine hesitancy despite the availability of free vaccination. The details of the government program can be found here.

The single greatest factor in vaccine hesitancy is worry over vaccine safety. This is understandable but we now have a huge amount of data on both effectiveness and safety. We have summarised the evidence for the side effects of Covid vaccines in another article.

The following vaccinations are available in Hong Kong:

    1. BioNTech vaccine: This is an mRNA vaccine. It represents a new technology in which a small segment of mRNA is injected into the body. This causes the body to produce spike protein and leads to the development of immunity. This vaccine (along with the Moderna vaccine which is also mRNA) report the highest efficacy rates. It is given as 2 shots 21 days apart. In Hong Kong, the datasheet for the vaccine given can be found here.

    2. Sinovac Biotech: This is a more traditional inactivated vaccine. This vaccine can be stored in a standard fridge making widespread use easier than the mRNA vaccines. It is given as 2 shots 28 days apart. The summary of the scientific committee findings reported to the CHP is available here.

Developing a COVID-19 Vaccine

The development of the COVID-19 vaccines occurred at an unprecedented rate. Normally vaccines develop through three phases of trials. These trials are mostly designed to answer a couple of questions.

    1. Is the vaccine safe?
    2. Is the vaccine effective in preventing disease and/or reducing disease severity?

The vaccine trials for COVID-19 were designed to identify a reduction in disease. The cases were generally symptomatic, mostly mildly symptomatic although there were some cases of more serious disease. The studies showed the vaccine candidates to be safe within the numbers involved and to show effectiveness in reducing cases of illness. The studies resulted in headline numbers for efficacy such as 95% BioNTech versus 50% Sinovac. A study from Hong Kong University published in the Lancet showed 10X higher antibody levels in patients given BioNTech in comparison to Sinovac. This has also been our findings with OT&P patients. We recently reviewed more than 800 post-vaccine antibody tests. We also saw significantly higher antibody levels after the BioNTech vaccination. These antibody differences would support the higher levels of real-world effectiveness with the BioNTech vaccine.

Following the phase 3 trials some questions required further ongoing research, these included:

    1. Is the vaccine effective in reducing or preventing transmission of the virus?
    2. How long is the vaccine effective and will booster doses be required?
    3. How does the vaccine behave in different populations?

The phase 3 studies proved that the vaccines reduced the likelihood of an individual developing severe illness. This is obviously very important. All the vaccines are very effective at preventing death and serious disease. In order to understand whether the vaccines also reduce transmission and asymptomatic infections, we needed more data from much larger population studies. Data from Israel and the UK initially, but now from studies all over the world, has confirmed a significant reduction in transmission, in infections and a reduction in severe disease. The data is stronger for BioNTech than for Sinovac. In Europe and the US, 99% of all deaths are currently occurring in non-vaccinated individuals.

The graph below clearly shows the effectiveness of vaccination on the Delta variant in the UK. The Delta is the most common variant circulating and is currently responsible for the vast majority of infections. The UK has vaccinated over 60% of the population based on age with the eldest down being vaccinated. BioNTech vaccine has been shown to be 96% effective in reducing hospital admissions from the Delta variant. The recent infections are occurring almost exclusively in the younger non-vaccinated fragment of the population. This graph shows that vaccination is clearly protecting the vaccinated sector of the population. Public Health England estimates that vaccination saved at least 10,000 lives in the first 3 months of 2021.

Figure 1: Percentage of Daily Covid Cases in the UK by Age 1-15 June 2021

The development of vaccine candidates represents an incredible scientific achievement. The new mRNA vaccines in particular represent an enormous leap in vaccine development in terms of management of current and future infectious disease. The vaccines are more effective than we could have hoped for and we have a very large database of vaccine safety, especially for the BioNTech vaccine. We are currently seeing one of the great medical advances of our lifetime.

Topics: COVID-19

OT&P Healthcare

OT&P Healthcare

OT&P Healthcare is a Premium Private Healthcare Practice in Hong Kong. Our priority is to help individuals to enhance and optimise their health by providing easy access to a wide range of excellent practitioners and information, supported by management systems and technology that ensure quality of service and value. Our Mission is to provide pre-eminent private healthcare in Hong Kong. We aim to be the best in class fully integrated healthcare service, providing a circle of care for all our patients' needs.