PETALING JAYA: A study should be conducted to collect data from our past experiences and cases to help decide who needs a booster or third dose of Covid-19 vaccines, say health experts.
They said this in response to Health Minister Khairy Jamaluddin’s recent announcement that the ministry was currently developing guidelines on third doses and booster shots for the vaccines.
“I am confident that we can start giving the third dose first, and then followed by the booster shots starting from next month once we get the views and clinical guidelines from experts,” he said.
Khairy had also explained that there was a distinction between a booster shot and the third dose.
“The third dose is given to those who may not have gotten the level of protection they need from the first two doses.
“And they require a third dose to achieve an optimum immune response.
“Booster shots are given to those who have enough immune response after receiving two doses of vaccine, but its response is slowly going down,” he said.
“The priority of giving this third dose will be focused on high-risk groups first, such as health frontliner members, immuno-compromised patients, the elderly with comorbidities and individuals living or working in long-term care facilities.”
Medical Practitioners Coalition Association of Malaysia president Dr Raj Kumar Maharajah said different countries have different factors and statistics, and we cannot just follow that lead.
“It’s not a hard and fast rule. We cannot say that the United States is giving booster doses to everyone aged 65 and above, so we should follow.
“The decision might be related to their environmental factors, lifestyle and how they were infected.
“In Malaysia, it may be a totally different scenario.
“That’s why we have to study our own data and decide who needs a third dose and booster dose,” he said yesterday.
Dr Raj Kumar said there is only “a very thin line” differentiating the booster shots and third doses because a third dose can be given to someone who wants a booster dose and vice versa.
“Basically, a booster dose is given to all the high-risk groups, such as those working on the front line and those with comorbidities like hypertension and diabetes.
“A booster is given because, for any vaccine, the effect wanes after six months as the antibody counts will reduce,” he said.
The third dose, he said, is given to those who have low immunity, like cancer and HIV patients, or are on certain medications that compromise their immunity level.
“They can be given the third dose as early as a month after the second dose. A booster dose, on the other hand, is given after at least six months.
“But when it comes to who is the right candidate for a booster or third dose, it can interchange. The same person can be eligible for both,” he explained.
Dr Raj Kumar also said that “retrospective studies” should be done to collect data from our past experiences and cases to help decide who needs a booster or third dose.
“For example, we can look at data of admission for Categories 4 and 5 that involves those aged 65 and above; how many ended up in the ICU and how many died.
“From these statistics, we can get a picture of the groups that are at higher risk and decide if they should get a booster dose,” he said, adding that an antibody test can also tell if a booster dose is needed.
Prof Dr Moy Foong Ming from Universiti Malaya’s Department of Social and Preventive Medicine also said that a booster and third dose are “interchangeable”, and many countries do not distinguish between them.
“The third dose is for those who are immunocompromised, like those on cancer treatment whose immunity is clinically diagnosed as low by a doctor.
“In the United Kingdom and the United States, it is given as early as 28 days after the second dose.
“A booster dose is given when the efficacy of the vaccine has waned over time. The normally observed period is between six and eight months.
“For the elderly, deciding whether they need a booster or third dose will depend on whether they are immunocompromised,” she said.
Although the terms could be confusing to the layman, Prof Moy said, for Malaysia, differentiating between a third and booster dose is probably important to ensure that those who require the third dose need not wait for six months.
However, the government must ensure that those who have not received even their first dose are vaccinated before rolling out the third or booster doses, she said.
“No matter how well protected we are, if a small group is left out, it can lead to an outbreak.
“There are cases, for example among foreign workers and the Orang Asli, where some of them only came for the first jab. We need to ramp up efforts to get them to have the second jab.”
“Nobody is safe until everybody is safe,” she added.
Malaysian Medical Association (MMA) president Dr Koh Kar Chai said a third dose is recommended for certain individuals who are not able to develop an adequate response with only two doses.
A blood test can measure our immunity level, he said.
“It can determine the groups that need either a third dose or a booster dose.
“However, the Health Ministry does not currently recommend the testing of antibodies to assess immunity.”
Independent health policies expert Dr Khor Swee Kheng, who suggested a “targeted booster policy” to prevent wastage, said there are “subtle differences” between third doses and booster doses.
“This depends heavily on our ability to measure the level of our immune response.
“Therefore, Malaysia’s vaccination strategy can consider including a way to measure someone’s levels of protection before providing them with a booster or a third dose.
“This can be a more targeted way to deliver booster shots without wasting precious vaccine supplies,” he said.