Updated: January 3rd, 2021
Answer: Of the two available vaccines in Hong Kong BioNTech is the most effective.
Both the vaccines available in Hong Kong are very good at preventing death and serious illness against the original SARS-COV-2 virus. However, we now have very good evidence that of the vaccines available in Hong Kong, BioNTech is significantly more effective. Specifically, BioNTech is more effective against the new variants including Omicron. 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:
- 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. A booster shot is recommended 6 months after the second dose. This can be reduced to 3 months for individuals travelling overseas. Information on booster eligibility can be found here.
- 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. A booster shot is recommended 6 months after the second dose. This can be reduced to 3 months for individuals travelling overseas. The booster dose can either be Sinovac or BioNTech. In individuals with no contraindication we recommend BioNTech vaccine for booster dose in people who took Sinovac as first series. Information on booster eligibility can be found here.
Evidence for COVID-19 Vaccines
The development of the COVID-19 vaccines occurred at an unprecedented rate. Early on there were understandable questions about effectiveness and safety. More than 9 billion doses of Covid vaccines have now been given worldwide. We have very good evidence for vaccine safety. The evidence that vaccines save lives is definitive. An individual who is vaccinated is between 10-15x less likely to die than a non-vaccinated individual. A booster dose makes an individual 4x less likely to be hospitalised than a vaccinated person without a booster. Vaccinated people still catch Covid but they tend to get less ill. The suggestion that vaccinations do not work is misinformation. The suggestion that vaccines kill people is disinformation.
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.
In another article we compare Sinovac with BioNTech as a head to head comparison.