SINGAPORE: With COVID-19 vaccinations in full swing and students over 12 years old eligible from this month, you or your family members may be gearing up for the first or second dose of the vaccine.
But why have some fully vaccinated people been infected? Can you do anything to boost your immunity before getting your shots? With similar questions in mind, Talking Point host Diana Ser spoke to infectious disease experts.
READ: Singapore accelerates national COVID-19 vaccination programme, students the next group to be inoculated
She came away equipped to separate fact from fiction and convinced that getting vaccinated “is the right thing to do”, not only for herself but “to help protect those around us”.
Here is what you need to know about this crucial aspect of the fight against the novel coronavirus.
WATCH: Why do vaccinated folks still get COVID-19? 10+1 common vaccination questions (8:10)
Q Pfizer-BioNTech and Moderna — what is the difference?
A In Singapore, the Pfizer-BioNTech vaccine has been approved for use in those aged 12 or over, while Moderna is approved for people aged 18 or above.
Their efficacy is about the same: 95 per cent for Pfizer-BioNTech and 94 per cent for Moderna. Both use mRNA technology, which teaches our cells to make a protein that triggers an immune response in our bodies.
READ: Pfizer-BioNTech COVID-19 vaccine safe for those aged 12 to 15, says committee in response to open letter by doctors
“The main difference is that the doses of the two vaccines are different,” said Ooi Eng Eong of Duke-National University of Singapore (NUS) Medical School. Pfizer-BioNTech uses 30 micrograms of mRNA, while Moderna uses 100 micrograms.
It does not mean the Moderna vaccine is thrice as potent as Pfizer’s. The difference is due to “guesswork” on the companies’ part “as to where the sweet spot for the dose of the vaccine is”, said the professor.
Q Does a higher dosage mean more side effects?
A It seems so, at least in phase three of the trial data, where side effects such as tiredness and rate of fever “appear to be more common in the Moderna vaccine” than the Pfizer-BioNTech vaccine, said Ooi.
“But we can’t be sure that it’s entirely due to dosage,” he added.
Side effects are caused by the body’s immune response to the vaccine. Out of more than 2.2 million doses administered as of Apr 18, there were 95 reports of suspected serious vaccine reactions, said the Health Sciences Authority.
That is a rate of 0.004 per cent, with 20 of these cases involving a potentially life-threatening allergic reaction called anaphylaxis.
READ: 0.13% of total COVID-19 vaccine doses administered reported to have suspected adverse effects: HSA
Q Will exercising the day before my jab boost my immunity and the vaccine’s efficacy?
A No, according to Tseng Hsien Cho, physician lead at the Raffles Medical Group. This is because some people may do too much strenuous exercise and experience discomfort the following day, which makes their immune system “worse than usual”, he said.
Regular exercise, a healthy balanced diet and adequate sleep, however, can help to maximise the vaccine’s efficacy. “Just one night of good sleep the day before can help to boost one’s immunity,” he said.
Q Could alcohol affect my immune response?
A Chronic alcoholism would “definitely” affect one’s immune system and “dampen a person’s immunity” to COVID-19. But having “a glass or two of alcohol” would not affect one’s immunity or the vaccine’s efficacy, said Tseng.
Q Will moving my arm help with the soreness? What else can I do after the injection?
A Yes, keeping the arm mobile improves its blood circulation and “prevents the joints from stiffening”, said Tseng.
Doctors would recommend a “light snack” before the vaccination, and adequate hydration before and after the injection. But drinking too much water “may cause swelling” and even water retention. “Just eat and drink as (you) would normally do,” he advised.
Q Will taking paracetamol before the jab help?
A No, doctors “don’t recommend taking medication without symptoms”, Tseng said.
Q If fully vaccinated people are getting infected, what is the point of the vaccine?
A With mutated forms of the virus that are “quite different from the original”, said infectious diseases specialist Leong Hoe Nam, this is akin to a course syllabus changing — a student who scored 95 marks previously may fare worse now.
“But even if we went back to the original strain … the (vaccine’s) efficacy was only 95 per cent,” he noted. “(Out of) 100 people, there are five (who’d) still end up with an illness, but we understand that to be mild.”
Vaccination “changes a severe disease to a mild disease” and a mild disease to an asymptomatic disease. Hence people have a “responsibility” to prevent severe forms of the disease, which require oxygen or intensive care, he said.
Otherwise, an “overloaded” healthcare system means other patients might not receive treatment for their ailments.
“It boils down to you and me getting vaccinated, making a deadly illness very mild or asymptomatic, protecting ourselves and keeping our healthcare institutions working well,” he added.
WATCH: The full episode — How effective is the COVID-19 vaccine? Why the vaccinated still get infected (21:55)
Q How long will my protection last?
A About 30 per cent of people overall will have antibodies that last for years at least, said Leong.
The other 70 per cent “won’t have enough”: The antibodies will fall in time or “never mount adequately”. In those cases, “you’ll need to remind the immune system by going for a booster vaccine”, he added.
Q How much of the population has been vaccinated? Is there a magic number?
A Nearly four in 10 residents have had at least one jab, and the next target is to get at least the first dose to two in three residents by early next month, Prime Minister Lee Hsien Loong said on Monday.
READ: Singapore 'on track' to bring COVID-19 outbreak under control; curbs may be eased after Jun 13: PM Lee
Initially, experts believed that herd immunity could be reached if 70 per cent of the population is vaccinated.
But with the new, more transmissible variants, “many experts around the world think that it should be about 80 per cent”, said Hsu Li Yang, the NUS Saw Swee Hock School of Public Health’s infectious diseases programme leader.
Herd immunity means “those who aren’t vaccinated will still be indirectly protected” because people around them are vaccinated, acting like a “shield”. The associate professor cautioned, however, that herd immunity does not mean COVID-19 “will go away”.
“There’ll still be occasional cases and maybe even clusters … after we’ve achieved the vaccination rate of about 80 per cent,” he said. “I’m not sure that there’s a magic number in this case.”
Q What will herd immunity look like? Will social distancing and masking up still be needed?
A “That’s like looking into the crystal ball,” said Hsu. Scientists are not sure, but as he sees it, this is unlikely to happen in “the next three to four years at least”.
Ultimately, it also depends on Singapore’s tolerance for COVID-19.
For countries that do not want a single case, even if 80 per cent or more of the population is vaccinated, people would still need to wear masks and be careful about travellers coming in across the borders, he said.
If the approach is to “reduce the risk of COVID-19” so that it becomes like the flu, and the population can accept “a few cases, a few outbreaks, maybe a few deaths”, then Singapore “can start peeling back our restrictions and mask-wearing and stuff”.
Watch this episode of Talking Point here. The programme airs on Channel 5 every Thursday at 9.30pm.