PETALING JAYA: Booster shots are needed as data in several countries have shown that immunity against the Covid-19 virus wanes after six months, say health experts.
Malaysian Society of Infectious Diseases and Chemotherapy president Prof Dr Zamberi Sekawi said data in Israel and the United States had shown that there was an increase of infection among those vaccinated as immunity waned.
The booster shots, said Dr Zamberi, were necessary but this has to be based on the recipients’ risk of getting severe infection.
He said however the general population should not be given the booster shots as most poor countries had not even received their first dose.
“This is a big issue – vaccine inequity – because certain rich countries give boosters but at the same time, (people in) most poor countries have not even received their first dose.
“If there is vaccine inequity, this will result in prolonging the pandemic because other countries are still not able to control the disease. So, it doesn’t make sense if it is just one country with very low cases but other countries have many infections.
“These are potential sources of transmission once international borders have opened up,” he said.
The World Health Organisation (WHO) has repeatedly called for a delay on administering booster shots as vulnerable people worldwide should be fully vaccinated first.
Dr Zamberi, who is also Universiti Putra Malaysia’s consultant clinical microbiologist, said more studies were also needed to know if there was a need to give booster shots to the general population.
“In immunology, we have another set of immune system known as the T-cells.
“The antibodies are the B-cells. B-cells are the ones that produce these antibodies but for T-cells, which are currently not detected by our standard test, we are unsure of how robust it is.
“Sometimes, antibodies are low but if the T-cells are very robust because of the vaccine, then we do not need to worry about the low antibodies as the other part of the immune system will work against the virus,” he said.
The T-cells immune systems, he added, needed to be looked into much more on whether the current vaccine actually stimulated the T-cells adequately.
Association of Private Hospitals Malaysia president Datuk Dr Kuljit Singh also agreed that booster shots should be given as data from other countries had indicated that immunity did come down after some time.
Dr Kuljit said there should not be any delay in procuring the vaccines as there would be a shortage once other countries also started looking into boosters for their population.
“I think what the government has decided is very timely.
“Let’s not delay because we may lose out again like what happened during April and May when we did not have many vaccines because other countries got it first as they planned it much earlier,” Dr Kuljit said.
He believes that depending on the data, the general population should be next in line for the booster shots once frontliners and high risk groups had received theirs.
“We will definitely have more local data by then. We would be able to see if after the booster shots the protection level becomes better,” he said.
“It will become evident by then if the infection rate is coming down and this is what we want to achieve – to see the pandemic going down to a level where we can start moving around more freely than what we have right now,” he added.
However, Medical Practitioners Coalition Association of Malaysia president Dr Raj Kumar Maharajah said it would be more prudent to first complete vaccination of all adults who had yet to receive a dose.
“The public health impact of this is stalling the spread of disease would be greater than booster doses.
“Similarly, vaccination of children aged 12 to 17 would help reduce the outbreak and indirectly protect others,” he said.
Dr Raj said should there be enough supply of the vaccine, booster shots could then be administered for those over 60, adding that there was also good data to suggest a three-dose regime for immunocompromised individuals.
He agreed that frontliners should be given priority as well as they belonged to the high-risk group who might easily be infected due to exposure.
Booster shots, said Dr Raj, could be offered to the general population once everyone had received at least two doses and the high-risk groups had received their third doses and there was still excess vaccine.
Public health measures, he stressed, must continue to be strengthened by keeping the face mask mandatory, improving ventilation, undergoing weekly Covid-19 testing and others.
“Vaccines must not be seen to be the be-all and end-all.
“Our current testing and contact tracing need to be greatly improved if we are to move to a form of endemicity that more closely resembles normalcy.”