Learning Modules

Module 1

Three common preventable infectious respiratory diseases

Module 2

Vaccine information

Module 3

Common Q & A

Module 4

Misinformation (Rumors)

Module 5

Hong Kong government’s support in vaccine promotion

Module 02

Vaccine information

01. Vaccination and herd immunity 02. Vaccines for three common infectious respiratory diseases 03. Vaccine development and principles 04. Vaccines for three common infectious respiratory diseases in Hong Kong and their modes of administration 05. Special populations and vaccination 06. Comparison of infection, complication, and mortality rate after vaccination 07. Comparison of long-term effects before and after vaccination 08. Precautions before and after vaccination 09. Relevant government's information

01. Vaccination and herd immunity

Herd immunity, also known as community immunity, occurs when a sufficient number of people in the community are immune to the pathogen causing the disease so that other non-immune individuals are protected from infection. The herd immunity theory suggests that when a large number of individuals in a group are immune to an infectious disease or when there are few susceptible individuals, the chain of infection of those infectious diseases that are transmitted between individuals will be interrupted.

02. Vaccines for three common infectious respiratory diseases

Types of vaccines	Mechanism of action	Brand			Characteristics
Inactivated or attenuated vaccine	Inactivated or attenuated virues are used. It can produce an immune response and does not cause a disease	COVID-19	Influenza	Pneumococcal Infection	Traditional infectious prevention technology and widely used Can be stored in a conventional refrigerator at temperatures of 2 to 8 degrees Celsius. Data shows that these kinds vaccines are safe and have few side effects but their duration of immunity is relatively short
Inactivated or attenuated vaccine		Corona Vac(Sinovac)	Inactivated Influenza Vaccine (IIV) Injection Live-attenuated Influenza Vaccine (LAIV) Nasal Spray	23-valent Pneumococcal Polysaccharide Vaccine (23vPPV) 13-valent Pneumococcal Conjugate Vaccine (PCV13)
RNA and DNA vaccines	Deliver viral RNA/DNA to the human body. The body cells are taught to prroduce their own SARSCoV2 protein fragments (vaccine antigens), which can induce an immune response in the body	BioNTech			New infectious preventing technology with relatively higher production costs Must be stored at 70°C Data shows that these kinds of vaccines are more effective in preventing mild disease and virus transmission, but are more likely to cause minor side effects

03. Vaccine development and principles

3.1 Vaccine development：

Generally, an experimental vaccine is tested in human clinical trials in four phases.

3.2 How the vaccines work：

04. Vaccines for three common infectious respiratory diseases in Hong Kong and their modes of administration

4.1 Coronavirus disease 2019

For CoronaVac (Sinovac) vaccine：
Age group	Number of doses and intervals
Age group	1st dose	Interval	2nd dose	Interval	3rd doses
18 - 49 years old	Recommended	28 days	Recommended	90 days	Recommended
50 years of above				90 days
Immunocompromised✽				28 days

*Immunocompromised persons include:

Cancer or hematological malignancy on active immunosuppressive treatment now or in the past 12 months
Recipients of solid organ transplant or stem cell transplant on immunosuppressive treatment
Severe primary immunodeficiency or on chronic dialysis
Advanced or untreated HIV disease
On active immunosuppressive drugs, or immunosuppressive chemotherapy / radiotherapy in past 6 months

This table was updated on 18 October 2023, for real-time information, please see： https://www.covidvaccine.gov.hk/pdf/covid19vaccinationfactsheet_coronavac_eng.pdf

For BioNTech vaccine:
Age group	Number of doses and intervals
Age group	1st dose	Interval	2nd dose	Interval	3rd doses
18- 49 years	Recommended	56 days#	Recommended	90 days	Recommended
50 years or above		28 days#		90 days
Immunocompromised✽		28 days#		28 days

*Immunocompromised persons include:

Cancer or hematological malignancy on active immunosuppressive treatment now or in the past 12 months
Recipients of solid organ transplant or stem cell transplant on immunosuppressive treatment
Severe primary immunodeficiency or on chronic dialysis
Advanced or untreated HIV disease
On active immunosuppressive drugs, or immunosuppressive chemotherapy / radiotherapy in past 6 months

#This dosing interval could be shortened to a minimum of three weeks for those with personal needs under informed consent after consideration of individual risk and benefit.

This table was updated on 18 October 2023, for real-time information, please see： https://www.covidvaccine.gov.hk/pdf/covid19vaccinationfactsheet_coronavac_eng.pdf

The Hong Kong Government's arrangements for the additional vaccine booster of COVID-19 in 2023:

Citizens belonging to the following priority groups: Citizens belonging to the following priority groups, if they have completed the initial doses, they can receive an additional vaccine booster at least 180 days after their last dose or recovery from COVID-19 infection (whichever is later) free of charge, regardless of the number of vaccine doses they received in the past:	Citizens belonging to other groups: An additional booster may be considered at least 180 days after the last dose / recovery from COVID-19 infection (whichever is later) for the following groups of citizens based on personal choice as recommended by experts if they have completed the initial doses. They will need to get the vaccine in the private market at their own expense.
Individuals aged 50 or above (including elderly living in residential care homes)# Persons aged 18 to 49 years with underlying comorbidities^ Persons aged 6 months or above and with immunocompromising conditions* # Pregnant women Healthcare workers	Children and adolescents aged 6 months to 17 years with comorbidities^ Healthy adults aged 18 to 49 years

*Immunocompromised persons include:

Cancer or hematological malignancy on active immunosuppressive treatment now or in the past 12 months;
Recipients of solid organ transplant or stem cell transplant on immunosuppressive treatment;
Severe primary immunodeficiency or on chronic dialysis;
Advanced or untreated HIV disease;
On active immunosuppressive drugs, or immunosuppressive chemotherapy / radiotherapy in past 6 months

^ Persons with underlying comorbidities:

Chronic cardiovascular (except hypertension without complications), lung diseases
Metabolic or kidney diseases, obesity (Body Mass Index 30 or above)
Chronic neurological conditions that can compromise respiratory functions or the handling of respiratory secretions, or increase the risk of aspiration, or those who lack the ability to take care of themselves
Children and adolescents (aged 6 months to 18 years) on long-term aspirin therapy

#The following citizens if only completed three doses, they are recommended to receive the next dose 90 days after 3rd dose free of charge:

Uninfected individuals aged 50 or above; or
Uninfected persons aged 6 months or above and

This table was updated on 18 October 2023, for real-time information, please see: https://www.chp.gov.hk/files/pdf/poster_recommend_dose.pdf

4.2 Seasonal Influenza

Seasonal Influenza Vaccination	Recommend the following groups to receive the vaccine
Inactivated Influenza Vaccine (IIV) Intramuscular injection	Persons ages 6 months or above, including infants, are recommended to receive the vaccine. People at higher risk of infection and complications include older adults, children, pregnant women, people with chronic illnesses (e.g., heart, lung, kidney diseases, metabolic disease) and who are immunocompromised, healthcare workers, poultry workers, pig farmers, and others whose work involve a higher risk of influenza infection. Older adults and the disabled living in residential care homes, and obese people (with a body mass index (BMI) value of 30 or above). People aged 50 or above are in the priority group to receive the seasonal influenza vaccination to reduce the risk of complications, hospitalization and death due to influenza. They are recommended to be vaccinated before the winter flu season. The reason for this is to give the body sufficient time to build up its immunity against the influenza virus, which usually takes up to 2 weeks.
Live-attenuated Influenza Vaccine (LAIV- nasal spray

Seasonal Influenza Vaccination

Recommend the following groups to receive the vaccine

Inactivated Influenza Vaccine (IIV) Intramuscular injection

Persons ages 6 months or above, including infants, are recommended to receive the vaccine.
People at higher risk of infection and complications include older adults, children, pregnant women, people with chronic illnesses (e.g., heart, lung, kidney diseases, metabolic disease) and who are immunocompromised, healthcare workers, poultry workers, pig farmers, and others whose work involve a higher risk of influenza infection.
Older adults and the disabled living in residential care homes, and obese people (with a body mass index (BMI) value of 30 or above).
People aged 50 or above are in the priority group to receive the seasonal influenza vaccination to reduce the risk of complications, hospitalization and death due to influenza.
They are recommended to be vaccinated before the winter flu season. The reason for this is to give the body sufficient time to build up its immunity against the influenza virus, which usually takes up to 2 weeks.

Live-attenuated Influenza Vaccine (LAIV- nasal spray

4.3 Pneumococcal Infection

Pneumococcal Infection	Recommend the following groups to receive the vaccine
13-valent Pneumococcal Conjugate Vaccine (PCV13)	Highly risk individuals who are aged 2 or above* should receive one dose of 13-valent Pneumococcal Conjugate Vaccine (PCV13), followed by one dose of the 23-valent Pneumococcal Polysaccharide Vaccine (23vPPV) one year later. Persons aged 65 and above without additional high-risk conditions*, is recommended to receive one dose of 13-valent vaccine or one dose of 23-valent vaccine.
23-valent Pneumococcal Polysaccharide Vaccine (23vPPV)

*The following are regarded as high-risk conditions:

History of invasive pneumococcal disease, cerebrospinal fluid leakage, or with cochlear implants
Chronic cardiac, pulmonary, liver or renal disease (except hypertension with no complications)
Metabolic diseases including diabetes mellitus or obesity (body mass index 30 or above)
Immunodeficiencies related to Asplenia, HIV /AIDS, malignancies or the use of systemic steroid
Chronic neurological diseases that affect the respiratory function, causing difficulty in handling respiratory secretions, increased risk of foreign bodies entering the lungs, or lack of self-care ability

For details, please visit the following webpage: https://www.chp.gov.hk/tc/features/103165.html#10004

05. Special populations and vaccination

Women in pre-pregnancy, pregnancy and breastfeeding	Persons aged 60 or above	Children and adolescents
Can reduce the risk of hospitalization and death in pregnant women, which is caused by a COVID-19 infection Antibodies produced by the vaccines may be transferred to fetuses through the umbilical cord Pregnant and breastfeeding women can receive BioNTech and Sinovac vaccines	85-97% effectiveness in preventing serious illness or death Persons with chronic illness but stable conditions can also be vaccinated to be protected by the vaccines Concomitant administration of influenza and pneumococcal vaccines can reduce hospital admissions and deaths among older adults	Children as young as 6 months can be immunized with Sinovac or BioNTech vaccines and there are no new safety concerns Children and adolescents aged 3 to 17 years who have received Sinovac or BioNTech vaccines are immunized. The vaccines are safe and well tolerated

Patients with malignant solid tumors	Persons with immune rheumatism	Glucose-6-Phosphate Dehydrogenase deficiency
CoronaVac（Sinovac）is safe and effective in patients with malignant solid tumors	According to the Hong Kong Society of Rheumatology, patients with rheumatic diseases should consider receiving the COVID-19 vaccines and the overall benefits of the vaccines far outweigh the risks	There is no data on the effectiveness of COVID-19 vaccination in this population. You can consult healthcare professionals.

06. Comparison of infection, complication, and mortality rate after vaccination

The total infection rate of the fifth wave of COVID-19 in Hong Kong was 15.8%, compared with among unvaccinated patients was 24.6%. The statistic illustrates that COVID-19 vaccines are effective in preventing infection. The overall fatality rate in this wave of COVID-19 was 0.71%, and the rate of death of unvaccinated persons infected with the COVID-19 was 2.87%.
Statistics comparing the infection and mortality rates before and after vaccination against influenza and pneumococcal infections are not yet released.

The table below illustrates that three doses of COVID -19 vaccines are effective in preventing infection and significantly reducing deaths.

	Total infection rate of the fifth wave	Unvaccinated patients	Persons who have received three doses of Sinovac vaccines	Persons who have received three doses of BioNTech vaccines
Infection rate	15.8%	24.6%	9.1%	3.4%
Mortality rate	0.71%	2.87%	0.04%	0.02%

The data in the table was released on 25th, Apr 2022 by University of Hong Kong. For more details, please visit: https://www.med.hku.hk/en/about-hkumed/knowledge-exchange/newspaper-columns/2022/apr/three-doses-of-covid-19-vaccines-prevent-infection-and-reduce-death

Prof. Gabriel Leung, Dean of Medicine, together with Prof Joseph Tsz Kei Wu, the University of Hong Kong, held a press conference on 22 March 2022 to update the public about the fifth wave of COVID-19 pandemic in Hong Kong. In the press conference, the professors mentioned that three doses of the vaccines could prevent 98% of serious illnesses and death cases!

The table below shows the effectiveness of vaccination in prevention of mild, moderate to severe illness and death for all age groups.

Types of prevention	Age	1 does		2 doses		3 doses
Types of prevention	Age	BioNTech	Sinovac	BioNTech	Sinovac	BioNTech	Sinovac
Effectiveness in preventing mild to moderate disease	20-59 years	37.4%	2.1%	31.0%	17.9%	71.5%	42.3%
Effectiveness in preventing mild to moderate disease	60 years or above	No evidence of effective protection*		No evidence of effective protection*		71.6%	50.7%
Effectiveness in Preventing severe disease	20-59 years	85.0%	60.9%	95.2%	91.7%	98.5%	98.5%
Effectiveness in Preventing severe disease	60 years or above	65.6%	40.4%	89.6%	72.2%	98.0%	97.9%
Effectiveness in Preventing death cases	20-59 years	93.7%	65.4%	96.4%	94.0%	99.4%	Insufficient mortality data for calculation#
Effectiveness in Preventing death cases	60 years or above	73.0%	51.2%	92.3%	77.4%	98.1%	98.3%

*No evidence of protection effectiveness due to small or negative utility values and large confidence intervals

#Insufficient mortality data for calculation

The table was updated in 6th, Oct 2022. Source: https://www.med.hku.hk/en/news/press//-/media/HKU-Med-Fac/News/slides/20220322-wave_5_omicron_PHSM_update_final.pdf

07. Comparison of long-term effects before and after vaccination

The vaccines reduce the risk of long term COVID-19 effects in patients with mild to moderate illnesses. In addition, some studies suggested that COVID-19 vaccination improves the persistence symptoms of long term COVID effects.

The risk reduction tends to base on two assumptions:

the vaccines reduce the severity of an acute infection;
the vaccines may help the body to clear the residual virus faster.

Note: Statistics comparing the long-term effects of influenza and pneumococcal infections before and after vaccination are not yet released.

08. Precautions before and after vaccination

8.1 Precautions prior receiving vaccination against common infectious respiratory diseases (e.g., COVID-19, Influenza and Pneumococcal vaccines)

Consult your doctor before vaccination if you have the following conditions:

You are allergic to any component of vaccines
Have had a severe allergic reaction or breathing problems with any previous vaccines
Feel anxious when receiving the vaccine
Have a serious or unstable chronic illness
Have a serious neurological condition
Have a bleeding problem
Have an HIV infection
Children and adolescents who are receiving medications containing aspirin or salicylates at the same time.
Have taken anti-influenza medication within the last 48 hours.

8.2 Precautions after vaccination

Common adverse reactions after receiving the vaccines against respiratory tract infections (e.g., COVID 19, Influenza, and Pneumococcal infection) include mild pain and swelling at the site of the injection for a short period of time. Most of these reactions subside spontaneously within two days. Some people may experience mild fatigue, fever, headache, muscle pain or chills.

If you have had an acute allergic reaction to any vaccines or have had a severe allergic reaction for any reasons, please stay in the rest area for 30 minutes after receiving the vaccine. For others, please stay for 15 minutes.
According to the World Health Organization (WHO), mild to moderate side effects after vaccination are normal and usually disappear on their own within a few days. If you experience any abnormalities after receiving the vaccine, please report them to your health care provider.

Possible side effects after vaccination of BioNTech or CoronaVac (Sinovac) vaccines

1: Watch out for possible side effects after receiving the BioNTech vaccines

Frequency	Side effects	% of patients possibly affected by the side effects
Very common	Injection site: pain, swelling Tiredness Headache Muscle pain Joint pain Chills Diarrhea Fever	>10%
Common	Injection site: redness Nausea, vomiting	≤10%
Unusual	Swollen lymph nodes Feeling unwell Pain in the arms Insomnia Itching at the injection site Allergic reactions (e.g. rash or itching) Loss of appetite Night sweats	≤1%
Rare	Temporary one-sided facial drooping Allergic reaction (e.g. Urticaria or facial swelling)	≤0.1%
Very rare	Myocarditis and pericarditis that can cause shortness of breath, heart palpitations, and chest pain	≤0.01%
Unknown	Severe allergic reaction Wide area of swelling at the arm being injected Facial swelling (facial swelling or in people who have had dermal filler injections) Skin reactions causing red spots or red patches appear on the skin (erythema multiforme) that may look like targets or a bull's-eye, darker in the middle with a lighter outer ring. Unusual skin sensations, such as tingling or crawling sensation (paresthesia) Decreased sensation or sensitivity, especially in the skin (hypalgesia) Excessive menstruation (most cases are not serious and temporary)	Cannot be estimated from available data

2：Watch out for possible side effects after receiving the CoronaVac（Sinovac）vaccines

Frequency	Side effects	% of patients possibily affected by the side effects
Very common	Pain at the injection site Fatigue, headache	≥10%
Common	Injection site: swelling, redness, hardness nausea, diarrhea Muscle pain, joint pain Coughing Chills Loss of appetite Sore throat	1% - 10%
Unusual	Warmth at the injection site Vomiting Fever Allergic reaction Skin, mucous membrane abnormalities Dizziness, drowsiness	0.1% - 1%
Rare	Muscle spasms Edema of the eyelids Nose bleeding Bloating Loss of sense of smell Eye congestion Hot flushes Constipation	0.01% - 0.1%
Very rare	Bell's palsy	≤0.01%
Severe	Eight severe adverse reactions were identified in the clinical trials, including myopathy, ulcerative colitis, allergic reaction, urticaria, fever, appendicitis, epilepsy, and rash.	Detailed data is not yet available

8.3 Statistics on abnormalities after COVID-19 Vaccination in Hong Kong

Until 31 August 2023 (inclusive), a total of about 20,847,200 doses of COVID-19 vaccines were administered. During the same period, the Department of Health received a total of 8,132 reports of adverse events following Immunization of COVID-19 vaccines. [Case rate: 0.04% (i.e., 39 cases per 100,000 doses received)], of which no fatal cases were related to immunization of COVID-19 vaccines.

Total numbers of doses	CoronaVac（Sinovac） About 8,896,300 doses	BioNTech About 11,950,900 doses
Total cases of Abnormalities reported (cases/100,000 doses received)	3,405 [0.04% (38.3)]	4,727 [0.04% (39.5)]

The above data was drawn on 31 August 2023, please check the real-time information: https://www.drugoffice.gov.hk/eps/do/tc/doc/Safety_Monitoring_of_COVID-19_Vaccines_in_Hong_Kong.pdf

09. Relevant government's information

9.1 COVID-19 vaccination programme:

https://www.chp.gov.hk/tc/features/106934.html
Vaccine booking System:
https://booking.covidvaccine.gov.hk/centre/index_tc.html

9.2 Influenza

The Government provides free or subsidized seasonal influenza vaccination programme to eligible persons and to encourage people aged 50 or above to receive the vaccines.
For more information, please visit the following website: https://www.chp.gov.hk/tc/features/18881.html

9.3 Pneumococcal Vaccination Subsidy Scheme 2023/24

Since 2009, the Government has been providing subsidy for Hong Kong residents aged 65 or above who have not received pneumococcal vaccination to receive one dose of 23-valent polysaccharide pneumococcal vaccine (23vPPV). Starting from 2017/18, an additional dose of subsidized or free 13-valent pneumococcal conjugate vaccine (PCV13) has been providing to older adults aged 65 or above (who are at high health risk).
For more information, please visit the following website: https://www.chp.gov.hk/tc/features/103165.html#10004