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All you need to know about the Moderna and Pfizer-BioNTech COVID-19 vaccine

Vaccination is one of the key strategies to protect us and our loved ones against COVID-19, along with safe management measures, contact tracing and testing. The Expert Committee on COVID-19 Vaccination proposed to vaccinate the population as widely as possible to not only reduce the number of people susceptible to the disease, but also the chances of transmission. As more of us are vaccinated, the harder it will be for the virus to spread, and the safer we will all be as a society. Learn more about the safety and efficacy of vaccines from our Raffles experts.

How do mRNA vaccines work?

The Moderna and Pfizer-BioNTech vaccines consist of messenger RNA (mRNA) which carries instructions to tell your body to make the spike protein of the virus. This then stimulates your immune system to produce protective antibodies against the spike protein.

How effective are the mrNA vaccines? What is their duration of effectiveness?

The Moderna and Pfizer vaccines have shown a 94 – 95% efficacy in preventing COVID-19. The vaccination consists of two doses, with the second dose administered 21 days later for the Pfizer vaccine and 28 days later for the Moderna vaccine. The vaccine is injected into the muscle of the upper arm (deltoid area) and both doses are necessary in order to develop full protection.
The vaccines continue to be effective for at least 2 months with no signs of waning protection. MOH will continue to monitor and review data on the duration of immunity.

Is the COVID-19 vaccine safe?

The Health Sciences Authority (HSA) and Expert Committee on COVID-19 vaccination have assessed that the Moderna and Pfizer-BioNTech COVID-19 Vaccines is safe and effective for the general adult population, including people with chronic medical
conditions. They have been granted interim authorisation for their
use in Singapore under the Pandemic Special Access Route (PSAR).

Who should not get the COVID-19 vaccine?

The Moderna and Pfizer-BioNTech COVID-19 Vaccines are not
recommended for those with a history of
1. Anaphylaxis or severe allergies,
2. Severe drug reactions, or
3. Allergic reaction to the first dose of the vaccine or its components.

The rate of anaphylaxis for the Pfizer-BioNTech vaccine was reported at 1 – 2.6 cases per 100, 000 vaccinations and 1 case per 400,000 vaccinations for the Moderna vaccine.

Some segments of the population are ineligible at this time
because of insufficient data. It is not recommended for
1. Pregnant women,
2. Severely immunocompromised persons, and
3. Children under the age of 16 for the Pfizer-BioNTech vaccine
and under the age of 18 for the Moderna vaccine.

Can the COVID-19 vaccine be co-administered with other vaccines (eg. Flu or pneumococcal vaccine)?

The vaccine should be administered alone with a minimum interval of 14 days before or after any other vaccine. There is no available data on the safety or efficacy of the vaccine if given simultaneously with other vaccines.

Can persons with prior COVID-19 infection be vaccinated?

Currently available data do not indicate any risks in those with prior COVID-19 infection. However, persons with prior COVID-19 infection are likely to be protected for at least the first three months after infection or longer. Priority would therefore be given to vaccinate those with no COVID-19 immunity. No routine testing by PCR or antibody testing is required to determine eligibility for vaccination.

Will the vaccine be effective against mutated variants such as the B117 strain?

There is currently no evidence that shows that existing COVID-19 vaccines are less effective against the new, more transmissible strain of the coronavirus.
Moderna and Pfizer-BioNTech have publicly stated that their vaccines are likely to protect against the new strain and are undertaking studies to formally confirm this. The Singapore Ministry of Health (MOH) will evaluate data as it emerges and review Singapore’s vaccine strategy accordingly.

Is serology testing needed after vaccination?

No, routine testing by serology is not required after getting COVID-19 vaccination to determine effectiveness of vaccination. Vaccinated persons who subsequently develop acute respiratory infections (ARI) subsequently would still need to be undergo COVID-19 testing as per MOH instructions.

Will vaccination interfere with COVID-19 testing?

As the vaccines are incapable of causing COVID-19, they will not cause false positive PCR test results.

(Source: Raffles Medical Group)



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