03 March 2021
Have you decided to protect yourself and your community by getting a COVID-19 vaccine?
If the answer is yes, you currently have two vaccine options in Hong Kong with a third COVID vaccine arriving later in 2021.
To help you decide, we bring you unique insights from Healthy Matters’ Expert Advisory Board Member, Joseph Blais, Registered Pharmacist in Hong Kong.
In this guide you will find an exclusive comparison table of the most important vaccine information. If you need more information, there are also additional resources and references at the end of this article. We hope that you find this guide useful.
Which vaccine should I choose?
This is a common question that healthcare professionals face when comparing all types of treatments, not only for COVID-19 vaccines. When comparing treatment choices for a particular disease or health condition, it is best to first evaluate the key characteristics of any drug or vaccine. Individuals choosing COVID-19 vaccines should consider these five characteristics in the following order:
1. Efficacy: How well does the vaccine work in the strict conditions of a randomised clinical trial?
2. Safety: What are the known vaccine side effects and how frequently do they occur in both the vaccine and placebo groups? What is the frequency of severe or rare side effects outside of the clinical trial setting?
3. Adherence: How simple is it to adhere to the recommended vaccine dosing schedule?
4. Cost: Fortunately, in Hong Kong there is no personal financial cost to receiving the COVID-19 vaccine. However, you should also consider the time required to book online (or at your doctor’s office), the time needed to receive the vaccine, and time to travel to your nearest community vaccination centre.
5. Availability, personal preferences and values: Do you prefer getting the vaccine in your doctor’s office or at a community vaccination centre? Do you want to read the published clinical trial results in a scientific journal?
The Hong Kong Government has signed purchasing contracts for three vaccines. Two vaccines (Comirnaty and CoronaVac) have been authorized for emergency use and are currently available in Hong Kong. The third vaccine from Oxford/AstraZeneca is expected to arrive in the third quarter of 2021 and information for this vaccine will be updated in this article soon.
Comparison: COVID-19 vaccine options in detail
Comparison: COVID-19 vaccine side effects
Side effects reported as the number of people may experience an adverse event (AE) out of 100 people vaccinated reported in percentage.
Professional Opinion: Which vaccine is the best?
First, it is important to acknowledge that both available options (Comirnaty from BioNTech and CoronaVac from SinoVac) are good vaccines. Since there are no differences in cost and adherence (both are two dose vaccines), we will focus on comparing efficacy, safety, and availability.
Comirnaty appears to be highly effective against both symptomatic COVID-19 (this includes mild forms of the disease) and severe COVID-19. CoronaVac is also highly effective against severe COVID-19, arguably the more important outcome. However, CoronaVac seems to be less effective for mild symptomatic cases of COVID-19.
At the individual level, both of these vaccines would be expected to be highly effective. If you are very concerned about getting even a mild case of COVID-19, then I would recommend Comirnaty given its higher efficacy as compared with CoronaVac. At this point in time, I would also generally recommend Comirnaty for adults aged > 60 years since there is very limited data on this population in the CoronaVac studies, and Comirnaty is effective in older adults.
When we indirectly compare the most common side effects, it appears that they occur more frequently with Comirnaty. The common side effects for both vaccines were generally mild, and usually resolved after 1-2 days. The frequency of a potential side effect should be considered if you need to physically use your arms or can’t afford to take 1-2 days of rest at home. So for younger people who are very busy working or looking after others, CoronaVac may be preferred to minimise taking time-off immediately after receiving the vaccine.
Lastly, in part because it can be stored in a refrigerator, you have more options to obtain CoronaVac. If you can’t schedule an appointment at a community vaccination centre that has Comirnaty, then it would be a great idea to obtain CoronaVac at a government or private clinic. A third approach, especially for those who do not plan to travel outside Hong Kong, or are not in the high priority groups, is to wait until the third quarter of 2021. You can make your decision once additional information is available and the Oxford/AstraZeneca vaccine is approved in Hong Kong.
A point of clarification: the Pfizer/BioNTech vaccine
You’ll often hear commentators discuss the Pfizer/BioNTech vaccine. In China and Hong Kong, Fosun Pharma has partnered with BioNTech to sell the vaccine, whereas Pfizer has these rights outside of China. It is fundamentally the same BioNTech vaccine, just that in China they have partnered with Fosun Pharma.
Sources and Additional Information
Comirnaty (Fosun Pharma/BioNTech)
Interim clinical trial results
1. Polack FP, Thomas SJ, Kitchin N, Absalon J, Gurtman A, Lockhart S, et al. Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine. New England Journal of Medicine. 2020;383(27):2603- 15. Available here
Rate of anaphylaxis in the US with mRNA vaccines
2. Shimabukuro TT, Cole M, Su JR. Reports of Anaphylaxis After Receipt of mRNA COVID-19 Vaccines in the US—December 14, 2020-January 18, 2021. JAMA. 2021. Available here
US Centers for Disease Control Vaccine Information
3. Available here
Hong Kong Food and Health Bureau
4. Report on Evaluation of Safety, Efficacy and Quality of Comirnaty COVID-19 mRNA Vaccine (BNT162b2) Concentrate for Dispersion for Injection. Available here
Press release announcing Phase 3 trial results, 5 February 2021.
5. Available here
Phase 3 clinical trial registration (Brazilian study)
6. Available here
Phase 3 Clinical Trial Design and Study Protocol (Brazilian study)
7. Palacios R, Patiño EG, de Oliveira Piorelli R, Conde MTRP, Batista AP, Zeng G, Xin Q, Kallas EG, Flores J, Ockenhouse CF, Gast C. Double-Blind, Randomized, Placebo-Controlled Phase III Clinical Trial to Evaluate the Efficacy and Safety of treating Healthcare Professionals with the Adsorbed COVID-19 (Inactivated) Vaccine Manufactured by Sinovac – PROFISCOV: A structured summary of a study protocol for a randomised controlled trial. Trials. 2020 Oct 15;21(1):853. doi: 10.1186/s13063-020-04775-4. Available here
Published Phase 1/2 Studies from China
8. Zhang Y, Zeng G, Pan H, Li C, Hu Y, Chu K, et al. Safety, tolerability, and immunogenicity of an inactivated SARS-CoV-2 vaccine in healthy adults aged 18–59 years: a randomised, double blind, placebo-controlled, phase 1/2 clinical trial. The Lancet Infectious Diseases. 2021;21(2):181- 92: https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30843-4/fulltext
9. Wu Z, Hu Y, Xu M, Chen Z, Yang W, Jiang Z, et al. Safety, tolerability, and immunogenicity of an inactivated SARS-CoV-2 vaccine (CoronaVac) in healthy adults aged 60 years and older: a randomised, double-blind, placebo-controlled, phase 1/2 clinical trial. The Lancet Infectious Diseases: https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30987-7/fulltext
Hong Kong Food and Health Bureau (has summary study results in Chinese)
10. Report on Evaluation of Safety, Efficacy and Quality of CoronaVac COVID-19 Vaccine (Vero Cell) Inactivated. Available here
Hong Kong Government
11. Authorisation of COVID-19 Vaccines under the Prevention and Control of Disease (Use of Vaccines) Regulation and Summary Data on Approved Products. Available here
12. Consensus Interim Recommendations on the Use of COVID-19 Vaccines in Hong Kong (January 7, 2021). Available here
Other Medical Resources
JAMA Covid-19 Vaccine Comparison
13. Creech CB, Walker SC, Samuels RJ. SARS-CoV-2 Vaccines. JAMA. 2021. Available here
Joseph Blais is a Registered Pharmacist in Hong Kong and PhD candidate in pharmacoepidemiology at the University of Hong Kong.