FAQs - About COVID-19 Vaccines

20 Aug 2023

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Table of Contents

About COVID-19 Vaccines
  • Which vaccines are approved for use in Singapore? Which of these vaccines are included in the national vaccination programme?
  • How do mRNA vaccines work?
  • Are mRNA vaccines a form of genetic modification?
  • Are the COVID-19 vaccines halal?
  • What are the differences between the bivalent vaccines (e.g. bivalent Moderna/Spikevax or bivalent Pfizer-BioNTech/Comirnaty) and the original vaccines?
  • What is the difference between the Bivalent Moderna/Spikevax and the Bivalent Pfizer-BioNTech/Comirnaty COVID-19 vaccines? Which should I receive?

Safety
  • Vaccines for COVID-19 have been approved for use in a shortened timeframe compared to other vaccines or drugs. How can we be sure that scientific rigour has not been compromised?
  • What is myocarditis and pericarditis? Can the vaccine lead to myocarditis and pericarditis?
  • How can I be sure that it is medically safe for me to get vaccinated?
  • Is COVID-19 vaccination safe for those with chronic illness such as hypertension, high cholesterol and diabetes?
  • Will the COVID-19 vaccine cause infertility?

Side Effects
  • What are the side effects of COVID-19 vaccination? What should I do if I suffer from any side effects?
  • What happens if I develop an allergic reaction to my first dose?

Effectiveness
  • How effective is the vaccine? How long does the protection last?
  • Can the vaccines protect me against all strains of COVID-19?

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About COVID-19 Vaccines

 Which vaccines are approved for use in Singapore? Which of these vaccines are included in the national vaccination programme? 
 A: The Health Sciences Authority (HSA) has authorised the Pfizer-BioNTech/ Comirnaty, Moderna/Spikevax, Novavax/Nuvaxovid and Sinovac-CoronaVac COVID-19 vaccines for use in Singapore.

The Expert Committee on COVID-19 Vaccination (EC19V) has also recommended the use of the Pfizer-BioNTech/ Comirnaty, Moderna/Spikevax and Novavax/Nuvaxovid COVID-19 vaccines by the majority of the population, and the use of Sinovac-CoronaVac by persons who are medically ineligible to receive the other vaccines. These vaccines are offered under the National Vaccination Programme. All are currently available in Singapore. Only vaccines deemed suitable for use in target population subgroups, and where overall benefits outweigh the known risks, are recommended for use by the Expert Committee.
 How do mRNA vaccines work? 
 A:The COVID-19 mRNA vaccine consists of messenger ribonucleic acid (mRNA) that carry instructions to make the spike protein of the virus. The mRNA used in the vaccine is synthesised and not extracted from actual viruses. After being given by intramuscular injection, the vaccine mRNA is taken up by cells which then produce the spike protein. This stimulates the production of a good antibody and cellular immune response to the spike protein that protects the vaccinated person because the spike protein is an important part of the SARS CoV-2 virus. The spike proteins are however incapable of forming SARS CoV-2 viruses or causing COVID-19 infection. The vaccine mRNA only persists for two days before it is naturally broken down by the body. It does not enter the nucleus of cells and hence cannot interfere with the DNA of the vaccine recipient.
 Are mRNA vaccines a form of genetic modification?
 A:No, they are not a form of genetic modification. The mRNA vaccine is in a form that is cannot be converted back to DNA. Since our human genome is made up of DNA, there is no possibility that the COVID-19 mRNA will interfere with or modify human DNA. The mRNA is completely degraded within 48 hours of introduction to the human body.
The spike protein generated through the introduction of the COVID-19 mRNA is recognised by the body’s immune system to develop an immune response (e.g. generation of antibodies), similar to what happens in a natural infection against COVID-19.
 Are the COVID-19 vaccines halal? 
 A: The Islamic Religious Council of Singapore (MUIS)’s position is that COVID-19 vaccines are permissible for Muslim use. Please refer to MUIS’ religious position on the COVID-19 vaccine here.
 What are the differences between the bivalent vaccines (e.g. bivalent Moderna/Spikevax or bivalent Pfizer-BioNTech/Comirnaty) and the original vaccines?
 A:The bivalent vaccines are based on the original vaccines. But instead of targeting only the original COVID-19 virus, the updated version also targets the Omicron variant. It therefore can provide better protection against newer COVID-19 variants. They are proven to be safe and effective.

What is the difference between the Bivalent Moderna/Spikevax and the Bivalent Pfizer-BioNTech/Comirnaty COVID-19 vaccines? Which should I receive?
A:Both bivalent vaccines target the Omicron variant in addition to the original virus. The Omicron variant targeted by the Bivalent Moderna/Spikevax vaccine is the BA.1 subvariant, while that by the Bivalent Pfizer-BioNTech/Comirnaty vaccine is the BA.4/5 subvariant.

There is currently no evidence that a specific bivalent vaccine is better than the other in terms of protection against future variants. As such, either can be chosen for booster vaccination.

Safety

 Vaccines for COVID-19 have been approved for use in a shortened timeframe compared to other vaccines or drugs. How can we be sure that scientific rigour has not been compromised?
 A: An accelerated development timeline for vaccines against COVID-19 was possible given the following:
a. Significant investment and dedication of resources from vaccine manufacturers to the ramping up of vaccine production;

b. The mRNA technology platform had already been in development for many years prior to the COVID-19 pandemic.

c. Strong global partnerships between many different partners including international organisations, governments, researchers and manufacturers;

d. Given the pandemic situation, recruitment for and conduct of the randomised controlled trials to identify the differences in disease risk between those given vaccines and placebo, are able to be conducted more quickly than in the absence of a pandemic.

e. Many trials have performed their trial phases concurrently, allowing for sufficient data to be produced in a shorter time.

Safety, scientific or ethical integrity have not been compromised, and no short-cuts have been made, but the unique circumstances and factors described above have allowed accelerated development.

Emerging real-world and follow-up data on the safety and effectiveness of the mRNA vaccines in other jurisdictions is consistent with the effectiveness of the mRNA COVID-19 vaccines observed in the Phase 3 trial data. This further supports that scientific rigour was not compromised in the development of the mRNA COVID-19 vaccines.
 What is myocarditis and pericarditis? Can the vaccine lead to myocarditis and pericarditis?
 A:Myocarditis and pericarditis are inflammatory conditions affecting the heart muscles and the outer lining of the heart, respectively. Patients may present with symptoms such as chest pain, shortness of breath or abnormal heartbeats. Local incidence rates remain low and the cases are usually mild and recover well.
 
As a precaution, all persons, in particular adolescents and younger adults, who have received any dose of the vaccine, should avoid exercise or strenuous physical activity such as running, weightlifting, competitive sports, or playing ball games for two weeks after receiving any dose of the vaccine.
 How can I be sure that it is medically safe for me to get vaccinated?
 A:

MOH has put in place steps to ensure it is medically safe before you are vaccinated. Before receiving your vaccination, you will have to complete a screening form, which contains questions to screen out those who are unsuitable for the existing COVID-19 vaccines (i.e. Pfizer-BioNTech/Comirnaty, Moderna/Spikevax, Novavax/Nuvaxovid and Sinovac-CoronaVac). You will only be vaccinated after you have completed the screening and assessed to be suitable to receive the vaccine. You may seek clarifications with the medical professionals onsite to assist with any medical queries that you may have. If you are unsure of your allergy history, the vaccination sites are able to securely access your allergy history if this information was previously documented by your healthcare provider.

Alternatively, you may consult your regular doctor for advice if you should receive the COVID-19 vaccination. Please note that any charges incurred for such pre-vaccination consultation with your own doctors are not covered under the COVID-19 vaccination programme. Your doctor may provide a memo on your condition which will be useful for the medical team at the vaccination site to assess your suitability for vaccination. However, the final decision as to whether you should proceed with vaccination will be made by the medical professionals at the vaccination site.
 Is COVID-19 vaccination safe for those with chronic illness such as hypertension, high cholesterol and diabetes?
 A:Persons with chronic illnesses are recommended to receive the vaccine for personal protection as well as protecting their loved ones. The participants of Pfizer-BioNTech/Comirnaty’s and Moderna's phase 3 trials and other studies included persons with medical comorbidities, who were at risk of serious, life-threatening disease and death from COVID-19 infection, and demonstrated effectiveness with no safety concerns reported in this group. Studies on the Novavax/Nuvaxovid and Sinovac-CoronaVac vaccines have also included persons with chronic diseases without safety concerns reported.
 Will the COVID-19 vaccine cause infertility?
 A:There is currently no evidence that the COVID-19 vaccines can cause infertility in vaccine recipients.

Side Effects

 What are the side effects of COVID-19 Vaccination? What should I do if I suffer from any side effects?
 A: 

The vaccine has been assessed to be safe for use. However, you may experience common side effects, similar to other vaccines. Most side effects are mild or moderate, and usually get better within a few days. The table below lists some common side effects that have been reported with this vaccine, and how to manage them.

Side Effects

How to Manage

Pain, redness, swelling at the injection site

Those with fever are advised to self-isolate at home until the fever subsides.

 

Paracetamol 1 to 2 tablets for the other side effects every 6 hours for adults or dosed accordingly to the child's weight as needed.

Fever, chills

Headache, muscle pain, joint pain

Tiredness

Rest

Lymph node swelling at neck or arms

Usually gets better by itself in a week or so


See a doctor if:

  • The side effects persist or get worse
  • The fever persists for more than 48 hours (2 days)
  • Respiratory symptoms such as cough, runny nose, sore throat, shortness of breath or loss of sense of taste and smell develop
  • Heart or chest symptoms such as chest pain, shortness of breath or abnormal heart beats develop.

In very rare cases, this vaccine can cause a severe allergic reaction. Signs of a severe allergic reaction include difficulty breathing, swelling of your face, throat, eyes or lips, a fast heartbeat, dizziness and weakness, a bad rash all over your body.  If you experience a severe allergic reaction, seek medical attention immediately. Call 995 or go to the nearest A&E immediately.

 What happens if I develop an allergic reaction to my first dose?
 A:You should seek medical attention, if you experience a possible allergic reaction to the first dose (e.g. eye or lip swelling, hives, generalised skin rashes, breathlessness).  Fever, chills, muscle pain, headaches, injection site pain are not allergic reactions.

You should discuss your suitability for subsequent COVID-19 vaccinations with your doctor. Persons with an allergic reaction assessed to be caused by the vaccine and who are advised by a doctor that they should not take subsequent doses of the vaccine, should adhere to the advice of the doctor.

Nevertheless, persons who had developed the following skin reactions to a previous dose of the mRNA-based vaccine may be able to receive a subsequent dose of the same vaccine if:

a. The skin reactions developed were non-severe and occurred more than four hours after vaccination without other symptoms

b. Non-specific skin symptoms such as itching without a rash, red patch(s) that occur beyond the injection site or development of eczema
c. There were flares of underlying skin condition such as psoriasis and eczema

Medical personnel at the vaccination sites will assist to assess the suitability of individuals to receive the vaccination before they are vaccinated.


Effectiveness

 How effective is the vaccine? How long does the protection last?
 A: Vaccinated persons can be infected. However, vaccination lowers the risk of infection, and offers good protection from severe disease and hospitalisation

Based on local data, vaccine effectiveness against severe disease from the first booster has been sustained for at least one year thus far, particularly in those 59 years and under.
 Can the vaccines protect me against all strains of COVID-19?
 A:Current evidence suggests that the Pfizer-BioNTech/Comirnaty and Moderna/Spikevax’s current COVID-19 vaccines continue to offer good protection against the various COVID-19 variants. Bivalent vaccines can offer better protection against Omicron and other COVID-19 variants than monovalent/prototype vaccines, and you are recommended to receive the bivalent vaccines when it is made available to you. 

MOH will continue to monitor the evolving situation and global studies of vaccine efficacy against the various COVID-19 variants.

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