Written by Dr David Owens
Updated on April 20th, 2021
The following FAQ answers some of the most common questions around COVID-19 vaccination.
Are the COVID-19 vaccines effective?
Answer: YES. They are extremely effective.
Ultimately all vaccinations work in two different ways:
1. Direct immunity:
This deals with the question: If I am immunized, how less likely am I to die or become seriously ill from a disease? This is about benefit to the individual.
2. Indirect (Herd) immunity:
This deals with the question: If lots of people in the population are vaccinated, will people who have not been vaccinated or whose vaccination has not been effective, also be protected? This is a measure of benefit to the population.
We now have a huge amount of data of effectiveness from large population studies. These studies consistently show the vaccines to be extremely effective. All of the vaccines seem to be very good at reducing the risk of serious illness and death in vaccinated individuals. We also have increasing evidence that the vaccines reduce milder cases and transmission to some degree. The evidence is currently stronger for BioNTech in studies of effectiveness both in terms of prevention of disease and transmission. It is estimated that the UK vaccine program saved more than 10,000 lives in the first 3 months of 2021.
We discussed the vaccine studies in a number of recent Podcasts with Professor Ben Cowling.
Are the COVID-19 vaccines safe?
We now have data from many millions of vaccine doses and the side effect profile seems to be comparable to many other vaccines which are given routinely. Some mild side effects are relatively common. We also have an increasing understanding of some very rare but serious potential side effects.
The recent serious side effects potentially relating to the Astra Zeneca and Johnson and Johnson vaccines is counterintuitively a good example of the safety data around vaccination. The rare condition in question, typically effects around 5 people per million per year. It seems to effect around 10 per million after vaccination (mostly younger females). This compares to the risk of thrombosis with the contraceptive pill (200 per million) or COVID-19 (>1000 per million).
It is, of course appropriate that any side effects are fully evaluated and in this case it is likely that this class of vaccinations will be reserved for older patients.
Regardless, we are identifying complications which are occurring at a rate of 1/20th of that attributable to the oral contraceptive pill which is available as an over the counter medicine in Hong Kong.
Will the vaccines be effective against the new mutations?
Answer: YES, although possibly not to the same degree
Some of these mutations are showing evidence of early escape from current vaccinations. The mutations in question are referred to as variants of concern (VOC). It seems likely from current evidence that vaccines will continue to be effective, although possibly not to the same degree. They still seem to be good at preventing severe disease, but lower effectiveness may negatively impact population immunity. The good news here is that widespread genetic tracing of the virus allows early identification of potentially important variants and it will be possible to modify RNA vaccines against these variants, if and when they become clinically relevant.
Hong Kong has so few infections, do we really need to vaccinate so many people?
The majority of experts in virology believe it is unlikely that the SARS-COV2 virus will now simply disappear. It is not impossible, but the ability of the virus to hide in symptomless individuals and also in animal reservoirs mean it is most likely to stay with us. That being the case, we really have only two options. The first is to stay locked down for ever with border controls and intermittent social distancing measures. The second is to develop immunity within the population. The acquisition of immunity can only be achieved by natural infection or immunization. Experience from other populations has shown that allowing the infection to spread has the potential to rapidly overwhelm health systems leading to high population mortality. Characteristics of our densely populated city make this option a nonstarter from a public health perspective.
High levels of population immunity via vaccination represents the best chance to protect the health system whilst removing existing public-health controls.
I understand OT&P will be giving COVID-19 vaccines, can I pay privately for vaccination?
The vaccination program will be run by the government and all vaccinations will be free. We will be continuing to support the Department of Health by assisting in this process. We will be allocated a supply of vaccines which can only be given to patients within the eligible groups. In the first instance OT&P will ONLY have access to Sinovac vaccine. Patients of OT&P who wish to take BioNTech vaccines should book online via a government centre here. The process is simple and very efficient.
Is the vaccine safe in pregnancy and breast feeding?
Answer: Early evidence suggests that the answer is YES
We are developing increasing information about the safety of vaccination in pregnancy, especially of the mRNA vaccines (BioNTech in Hong Kong). Pregnancy is associated with an increased risk (although still small) of Covid and the UK has recently began to offer vaccination in pregnancy. Every public health intervention involves a risk benefit analysis and this is especially the case when community infections remain so low. Pregnant or nursing mothers should discuss the risk benefits of vaccination with their doctor.
Should children be vaccinated?
Answer: Not yet
There is currently no evidence for any COVID-19 vaccinations in children under 16 years (18 years for Sinovac) although vaccine trials in children are now underway. There is good evidence that risks of COVID-19 are very low in young people. They are not zero, but any public health intervention must involve a risk-benefit analysis. It is unlikely that there will be widespread vaccination of young people until we have greater evidence of the effectiveness and safety of the vaccinations in children.
I have had COVID, should I still be vaccinated?
Answer: YES, you will only need 1 shot
In Hong Kong it is advised to delay vaccination until at least three months after COVID-19 infection. Previous infection is not a contraindication to vaccination. Only one shot is needed to effectively boost natural immunity.
Is it possible to choose which vaccine to take?
The Hong Kong Government has indicated that individuals can choose which vaccine they wish to take. OT&P will only be able to give Sinovac in our clinics. Both Sinovac and the BioNtech vaccine are available in government vaccination centres. Information about the government program and vaccination booking is available here.
Is the BioNTech vaccine available in Hong Kong the same as the Pfizer vaccine in Europe and the US?
The BioNTech vaccine is manufactured in Europe and flown directly to Hong Kong from Frankfurt. Fosun has a distribution licence for the BioNTech vaccine in China. The vaccines given in Hong Kong are exactly the same as those given in Europe.
Can the BioNTech vaccine change our DNA?
The BioNTech vaccine is a messenger RNA vaccine. The mRNA enters the outside of the cell (the cytoplasm). It does not enter the nucleus and it does not (and is not able to) integrate or change the DNA. The mRNA in the vaccine has a short half-life and is gone from the body in 7-9 days. mRNA vaccine research has been ongoing since the mid 1990’s.
Can I take more than one type of COVID-19 vaccination?
Answer: In the future, YES
Immunisation should be completed with a single vaccination type so that the first and second dose will be the same brand of vaccine. In the first instance the government will provide one series of vaccination for every eligible individual in Hong Kong. It may be that in the future we give subsequent boosters with different vaccines but this will be dependent on further research. The RNA vaccines are likely be used to cover new or evolving variants in the future.
We will continue to update this page as we receive more questions relating to the vaccines.