COVID-19 Vaccinations in 15 easy questions

Written by Dr David Owens

Updated on September 16th, 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 have written another article on Herd immunity here.

It is impossible for Hong Kong to achieve Herd Immunity by vaccination alone. We have explained the reasons for this in another article. It is inevitable that the disease will get into Hong Kong eventually. For this reason, it is especially important that elderly and vulnerable people are vaccinated.

We now have a huge amount of data of effectiveness from large population studies. 99% of deaths in Europe and the US are now occurring in non-vaccinated individuals. 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 which is the best of the available vaccines in Hong Kong.

Are the COVID-19 vaccines safe?

Answer: YES

There is no reason to believe that vaccines in Hong Kong are any less safe and effective than they have been shown to be in the rest of the world. More than 3.8 billion vaccines have been given worldwide. One in every 8 people on the planet has now been vaccinated against Covid. The side effect profile seems to be comparable to many other vaccines which are given routinely. Some mild side effects are relatively common. We have summarised the evidence of side effects of Covid vaccines in another article.

We must also appreciate the potential complications of Long Covid. Studies in Europe and the US suggest that up to 10% of people who suffer from Covid develop long term symptoms. This means that there are significant potential side effects to not being vaccinated.

Which is the most effective vaccine in Hong Kong

Answer: Both vaccines protect against death and serious disease but we now have good evidence that BioNTech is the most effective vaccine

Studies showed both vaccines to be effective in reducing cases of serious illness. The studies resulted in headline numbers for efficacy such as 95% BioNTech versus 50.7% Sinovac. Numerous international studies have shown the vaccines to reduce death, illness and transmission of infection. The data is stronger for BioNTech in all of these measures. Recent studies have shown higher antibody response for BioNTech than 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.

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. We have another article explaining the evidence for the variants here. 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. Recent studies from the UK showed that for the Delta variant (the most worrisome in terms of vaccine escape) the BioNTech vaccine is 88% effective. Even when illness occurs it is much more likely to be mild or asymptomatic. We do not yet have evidence of the effectiveness of Sinovac but is likely to be less effective. 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. So far, the vaccines are still very effective in population terms.

Hong Kong has so few infections, do we really need to vaccinate so many people?

Answer: YES

We have explained in another article that it is very unlikely that Hong Kong can achieve Herd immunity by vaccination alone. The 70% figure, often quoted by public officials will simply not be enough. That being the case, we really have only two options. The first is to stay locked down forever 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 especially of the elderly and vulnerable, represents the only chance to protect the health system whilst removing existing public-health controls. It is simply impossible to keep this disease out of our city forever. If we do not get higher vaccination rates in the vulnerable population we will see significant mortality and the health system will be overwhelmed.

I have elderly parents/family members should they be vaccinated?

Answer: ABSOLUTELY YES

A 75-year-old is 9x more likely to be admitted to hospital and 230x more likely to die of Covid than a young person. For an 85-year-old, hospitalisation increases to 15x and death to 600x compared to a younger person. Covid vaccination significantly reduces death and severe disease in the elderly. Elderly and vulnerable patients and people who work or live with the elderly and vulnerable should be vaccinated as soon as possible.

Elderly people have fewer side effects to vaccination than younger people and other than in exceptional circumstances there is no reason to have a body check or medical clearance before getting a Covid vaccination.

Do I need a body check before I have a COVID-19 Vaccine?

Answer: No

Would you have a body check before having a flu jab? People who have underlying medical conditions should ideally always have them controlled. Individuals with other illnesses are generally at greater risk of COVID-19 and it is even more important that they are vaccinated.

I have high blood pressure and/or diabetes can I have a COVID-19 Vaccine?

Answer: Yes

If you have high blood pressure and/or diabetes they should ideally be controlled but it is even more important for you to be vaccinated.

I understand OT&P will be giving COVID-19 vaccines, can I pay privately for vaccination?

Answer: No

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 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 breastfeeding?

Answer: 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-19 and many countries including Hong Kong now 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 who have any concerns should discuss the risk benefits of vaccination with their doctor.

Should children be vaccinated?

Answer: Children from age 12 can now be vaccinated in Hong Kong

There is now evidence of safety and effectiveness for some COVID-19 vaccinations in children. Hong Kong has approved the BioNTech vaccine from age 12. There is good evidence that the 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. Parents who have any concerns about Covid vaccination should discuss the risk benefits of vaccination with their doctor. We have produced another article discussing vaccination in children available here LINK HERE.

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?

Answer: YES

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 different vaccines and our analysis of which is the most effective vaccine is available here.

Can the BioNTech vaccine change our DNA?

Answer: No

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-1990s.

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 doses 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.