For individuals with previous COVID-19 infection, do they still need to take COVID-19 vaccines?
Check out the government's recommendations on the use of COVID-19 vaccines in persons with previous COVID-19 infections on 13 March 2022 (PDF) .
Another wave of COVID-19 outbreak hits HK and many places are included in the Lists of Specified Premises of Compulsory Testing Notices. Where can I check the latest list?
Through searching on the List of Buildings with Confirmed /Probable Cases of COVID-19, you can find the latest updates.
If I need to do compulsory testing, what should I do? How can I get tested?
For arranging compulsory testing, you can visit the government’s Booking System of Community Testing Centre and make an appointment in advance to avoid long queues for testing. By checking the Status of Booking Service of Community Testing Centres, you can have a better picture of the availability of each centre in real-time and arrange your cross-district testing.
Besides waiting for SMS notification of test results, you can also visit COVID-19 Electronic Vaccination and Testing Record System to check the status. All you need is your ID no. and Specimen Bottle No. for a quick check.
What are the differences among the 2 vaccines that are available in Hong Kong and how do they work?
The Sinovac vaccine (CoronaVac) is an inactivated vaccine made of deadened coronavirus which is injected into the human body to stimulate an immune response.
The BioNTech vaccine (BNT162b2) is an mRNA vaccine, which injects the genetically modified RNA of the spike glycoprotein into the human body to teach the cells to produce spike glycoprotein and antibodies.
How long does the vaccine last?
In general, vaccine-induced immunity fades over time. Although there's no concrete data about how long immunity will last, the COVID-19 vaccines are believed to offer protection for at least 6 months.
Can I still be infected or infect others after I’ve received the vaccine? Do I still need to wear a mask afterwards?
According to the AstraZeneca clinical trials, a few vaccinated individuals who didn't have symptoms tested positive for the virus. It's common to have the virus but never experience symptoms, and it's possible to spread the virus to others even when you don't have symptoms. That's why you should continue to wear masks and maintain other preventive measures until there is herd immunity.
Will the vaccines be effective against the new strains of COVID-19?
Initial studies have shown that the vaccines may still be effective against the new strains of COVID-19, although there may be a drop in efficacy.
In general, what is the sample size for clinical trials? How many times were the trials performed for the new vaccine?
Vaccine development includes pre-clinical testing on animals and 3 stages of human clinical trials. In general, the sample size in vaccine efficacy trials is over tens of thousands, which is considered as statistically significant. After a vaccine is adopted, it should be closely monitored to evaluate the efficacy and safety.
Is the new technology in the mRNA vaccine safe enough to inject? What happens to the mRNA after it's injected into the body?
mRNA technology is relatively new, but has been studied for over 10 years. It has also been used in the development of some vaccines such as the rabies vaccine. mRNA vaccines teach our cells how to make a protein that triggers an immune response. After vaccination, the mRNA will be broken down by the body and won't enter the nucleus of the cell or affect our DNA. However, more time is needed to observe if there're any long-term adverse effects.
What are the common side effects?
Like any vaccine, the COVID-19 vaccines may cause side effects, which means your body's immune system is working. Different vaccines may cause different side effects in different people. Common side effects are usually mild and temporary, such as mild fever, soreness, redness or swelling at the injection site. In rare cases, people may experience more adverse side effects.
What should I do if I experience side effects after vaccination?
Common side effects are usually mild and temporary which will resolve within 1 to 2 days.
To reduce pain and discomfort where you got the shot, you may apply a clean, cool, wet washcloth over the area. Gently exercise your arm.
To reduce discomfort from mild fever, drink plenty of fluids.If the side effects persist or adverse complications occur, you should seek medical attention immediately.
I've received the flu vaccine every year and didn’t experience any allergic reaction. Does this mean I have less chance of experiencing an allergic reaction after receiving the COVID-19 vaccine?
It depends on which type of COVID-19 vaccine you receive. The flu vaccine is usually an inactivated vaccine, which is a different technology than the BioNTech vaccine. In spite of this, if you haven't experienced any adverse effects previously, the likelihood of adverse effects after COVID-19 vaccination is rare.
Who should not get the vaccine?
- History of allergy to vaccine or any of its components OR History of severe allergy reactions (e.g. anaphylaxis, angioedema, dyspnoea)
- Severe Neurological Condition E.g. Transverse Myelitis, Guillain-Barre Syndrome, Demyelinating Disease
- Severe Chronic Disease E.g. severely weakened immune system, severe bleeding disorder
- Pregnant or breastfeeding
If you are unsure about your medical condition, please consult your family doctor.
Who are suggested to get vaccination later?
-Those with uncontrolled/ unstable chronic disease (e.g. Blood pressure >160/100*; HbA1c >8%*; With symptoms; Undergoing treatment adjustment)
- Recent illness (e.g. Heart attack, or stoke in recent 3-6 months, acute feverish illness)
*subject to individual assessment and clinical judgement
If you are unsure about your medical condition, please consult your family doctor.
Should pregnant women get vaccinated?
Please consult your family doctor before vaccination.
Do I need to pay for the vaccination?
The Hong Kong Government is implementing a territory-wide COVID-19 Vaccination Programme free of charge for all Hong Kong residents.
How many doses are needed and how far apart should they be?
The BioNTech and Sinovac vaccines all require 2 doses. The 2 doses should be given at least 21 days apart for the BioNTech vaccine and 28 days apart for the Sinovac vaccine.
Can I receive different types of the vaccine for the first and second doses?
You should receive the same vaccine for both doses.
How many people must receive vaccines in order to develop herd immunity?
This depends on the types of vaccines received and their efficacy rate. In general, at least 75% of the population needs to get vaccinated in order to achieve herd immunity.
Can I choose which vaccine to take?
Vaccine availability depends on factors like recipient group, settings and vaccine delivery schedules. If you prefer to choose a specific type of vaccine, you can pick a location where it is available.
Will the vaccines be equally effective in people with different weights? Will everyone receive the same dosage?
Studies have shown that there isn’t an observable difference in vaccine efficacy among people with different weights. Everyone will receive the same dosage.
