COVID-19 Vaccines

After getting a vaccination, your immune system is trained to recognise the virus and produce antibodies which attack the virus and remain in our bodies. In doing so, the immune system will be able to recognise the virus in the event of an infection and fight off the virus before it causes any symptoms.

Pfizer-BioNTech and Moderna are messenger RNA (mRNA) vaccines, while Sinovac uses an inactivated vaccine technology.

• mRNA vaccines contain material from the COVID-19 virus that instructs our cells to produce a protein that is unique to the virus. After our cells make copies of the protein, they destroy the genetic material from the vaccine. Our bodies recognise that the protein should not be present and work to produce antibodies to attack the virus.
• Inactivated vaccine technology uses weakened or inactive viral particles to stimulate our body to produce antibodies that will help neutralise the COVID-19 virus.

Some coronavirus vaccines require multiple doses, with the doses given weeks or months apart. This allows us to produce longer-lasting antibodies and develop memory cells, so that our bodies and immune systems will be able to quickly fight the virus if we are exposed to it again.

Read more about how vaccines work.

References: gov.sg, World Health Organisation

The Singapore government has advised that COVID-19 vaccination, together with safe distancing measures, contact tracing and proactive testing, will help to protect us and our loved ones against COVID-19. Vaccination will not only reduce the number of people susceptible to the coronavirus, but also reduce the chances of transmission in the community.

The Ministry of Health in Singapore has stated that only vaccines that comply with the World Health Organisation’s guidelines and adhere to strict standards of safety, quality and efficacy have been identified and will be used in Singapore.

Learn more about how the vaccinations are accessed and monitored on gov.sg.

Based on current data, the mRNA vaccines are found to be effective. Pfizer BioNTech’s vaccine has a reported 95% effectiveness while Moderna’s has charted a 94% efficacy.

Sinovac, which uses inactivated vaccine technology, has been found to be 50.4% effective.

According to Dr Adrian Chan, respiratory physician at Mount Elizabeth Novena Hospital, the side effects of the COVID-19 vaccine are similar to those of the influenza vaccine.

These can range from mild symptoms such as pain at the injection site, fatigue and tiredness, muscle aches and chills, to more severe (but less common) symptoms such as fever and vomiting. There have been case reports of severe allergic reactions (anaphylaxis), but based on current data so far, the overall incidence of such reactions is low.

While COVID-19 vaccination in Singapore is voluntary, the government is encouraging all individuals who are medically eligible to be vaccinated when it is available. When more people in a community are vaccinated, the harder it is for a disease to spread.

Dr Leong advises, however, that generally, coronavirus vaccines are not recommended, for pregnant women or breastfeeding mothers.

“If you have multiple allergies or severe allergies (not just one class of drugs but 4 – 5 classes of drugs), you should be cautious as well. At this moment in time, there is also insufficient data to conclude that the vaccine is safe for those less than 16 years old so we do not recommend vaccination for this age group at this point of time.”

Both vaccines target different viruses. Therefore, it is recommended that while we protect ourselves against COVID-19, it is also prudent to protect ourselves against influenza by vaccinating ourselves with the influenza vaccine.

COVID-19 vaccines are not 100% effective. Time is also needed for more people to receive the vaccination, and some individuals may be unable to take the coronavirus vaccines or do not wish to do so. For these reasons, it is recommended to continue current safety practices such as regular hand washing and sanitisation, wearing your masks, and keeping to social distancing measures.