Vaccination reduces severity of infection

Dr Liew Shan Fap gets his Covid-19 vaccination jab.

KUCHING: While the efficacy of vaccination in preventing the Covid-19 infection ranges from 50 to 95 percent, it does importantly reduce the severity of infection by the virus, said Dr Liew Shan Fap.

The Society of Private Medical Practitioner Sarawak (SPMPS) president pointed out that the vaccines approved by Ministry of Health (MOH) are proven to be very effective in preventing serious complications of Covid-19 infection.

He noted that it is still possible for individuals who have been inoculated to get infected and become spreader for Covid-19.

“The Covid-19 vaccination does not protect individuals 100 percent from getting Covid-19 infection, but it will reduce the severity. The approved vaccines by MOH are proven very effective (nearly 100 percent) in preventing serious complications of Covid-19 infection such as pneumonia, admission to intensive care unit (ICU) and death.

“It is important to know that after the vaccination, individuals can still get the infection and become spreader for Covid-19. However, the risk of spreading the infection is lower as the Covid-19 infection is generally milder in vaccinated individuals,” he said.

He was commenting on health director-general Tan Sri Dr Noor Hisham Abdullah’s recent statement on how 40 of Malaysia’s healthcare workers were infected by Covid-19 after completion of their vaccination.

Dr Liew who is also the vice-chairperson of Malaysian Medical Association (MMA) Sarawak stated that the optimal protection of the vaccination will be achieved about one to two weeks after the second dose.

He added that those who have received their vaccination must still maintain and comply with the standard operating procedures (SOPs).

“The SOPs will change when we have achieved herd immunity in which more than 70 percent of the population have been vaccinated. Hopefully wearing face mask will be optional by then.

“However, we will live in ‘new normal’ social environment with new SOPs as the Covid-19 virus will be with us for a very long time,” he said.

Dr Liew also advised the people to register themselves and go for the Covid-19 vaccination as well as to continue complying with the SOPs.

Dr Tan Cheng Siang

Meanwhile, Dr Tan Cheng Siang pointed out that the manufacturers of Covid-19 vaccines have never claimed that the vaccine will prevent an infection.

The senior lecturer of Faculty of Medicine and Health Sciences, Universiti Malaysia Sarawak (Unimas) stated that while an ideal vaccine is intended to prevent infection and the manifestation of the disease, most vaccines are far from ideal.

“For instance, the Covid-19 vaccine trials were carried out as an observational study; vaccinating two groups of people, one group received the real vaccine and the other received a placebo (non-vaccine). They observe how many people from each group will develop Covid-19 related symptoms and by comparison, the value of the vaccine efficacy was determined.

“Thus, the clinical trial for each vaccine provides evidence that the Covid-19 vaccination can prevent the development of Covid-19 related symptoms. They did not perform the challenge experiment in which SARS-CoV-2 virus was deliberately used to infect the vaccine recipients to prove that the vaccine can prevent an infection,” he explained.

When asked whether those who have been vaccinated can infect others or become spreader for Covid-19, Dr Tan said the risk may be lower, but more research must be carried out to determine the actual risk involved.

“The viral load (concentration) of the virus in the respiratory tract of a vaccinated individual might be lower than that of an unvaccinated individual. So, it is still possible for a vaccinated individual to spread the virus to others since the vaccine may not prevent infection.

“Usually, it takes around one to two weeks for the body to produce antibodies after vaccination but the actual time for a person to develop antibodies can differ from one person to another. The level of antibody produced may also contribute to the immune status,” he added.

On the possibility of people needing a third dose of Covid-19 vaccine as recently stated by Pfizer chief executive officer Albert Bourla, Dr Tan stated that it is a little too soon to speculate.

Having said that, he pointed out that the people need to learn to embrace the new normal until there are more medical breakthrough to overcome the pandemic.

“Maybe, it is too soon to speculate but antibodies will generally wane over time without stimulation and a booster dose is required to keep the antibody level high enough to confer protection. “The Faculty of Medicine and Health Sciences, Unimas is currently conducting research to determine the longevity of anti-SARS-CoV-2 antibodies post-vaccination. I would be able to answer this question better in a few months’ time,” he said.