As the global debate over Covid booster shots gathers steam in wealthier countries, public health experts in Bangladesh contend it is still "premature" to roll out the third dose in this country.

They say that available vaccines would be better used to inoculate the unvaccinated -- not to mention that a large swath of the population in Bangladesh is yet to get the first shot.

Though some wealthier countries have already started administering the booster shots, the experts say there is no credible scientific evidence, except some sponsored studies, so far to support the need for the same.

Instead they urge the government to strengthen the ongoing vaccination drive and increase its coverage to ensure that at least 80 percent of the eligible population are inoculated with the first shot at the earliest.

Read: Resource for journalists around the world on COVID-19 vaccines

Some say the world may get very effective oral medicines to defeat the deadly virus in a couple of years.

Vaccination scenario

According to the Directorate General of Health Services (DGHS) in Bangladesh , a total of 57,124,899 people received the first dose of Covid vaccine while 35,690,258 both the doses as of November 24.

Bangladesh rolled out its regular mass inoculation drive in February. Jabs of four foreign pharmaceutical companies -- Pfizer, AstraZeneca, Moderna and Sinopharm -- are being administered across the country.

Lack of credible evidence

ASM Alamgir, principal scientific officer at the Institute of Epidemiology, Disease Control and Research (IEDCR), said only a few countries have started administering the third or booster doses of Covid vaccine.

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"Still there is no credible scientific evidence that underscores the need for a booster dose. I think the booster dose should not be given unless there's scientific evidence to bolster its need. I fear the booster dose can have side-effects,” he said.

According to the scientist, only some studies sponsored by vaccine companies have advocated the need for inoculating the booster doses. “There're many reasons not to believe these studies.”

"The government is now focusing on reaching its target of fully vaccinating the country’s 80 percent population. We’ll make a decision on the booster dose later. We won’t be influenced by the pharma company-sponsored studies.”

He said IEDCR, along with icddr,b, has been carrying out a study on the efficacy of the Covid vaccines in boosting antibodies, and the results may be published by the end of the year. “This may help us understand whether we need a booster dose or not.”

Still not feasible

Dr Be-nazir Ahmed, a member of the National Immunisation Technical Advisory Group or NITAG, said they are not currently thinking of booster doses for Bangladeshis.

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“We have not yet been able to give even the first dose of Covid vaccine to the targeted population. So, it is premature to consider the booster dose before administering the two shots to at least 80 percent of people."

According to him, only 30 percent of people in Bangladesh have so far received the first dose of Covid vaccine. “We have to inoculate at least 50 percent more with the first shot before thinking of booster doses.”

Who may receive booster shots?

Dr Be-nazir said the booster shots can be given to a person who received the two doses at least six months ago. “So, an insignificant percentage of people are now eligible for booster doses in Bangladesh.”

"Also, the necessity of the third dose depends on some factors, including the type of vaccine, its performance and the duration of its effectiveness among different age groups," the expert added.

He said studies in the US and the UK found that the level of antibodies in those who received the Pfizer vaccine dropped after four months. “We have to carry out comparative studies to know the performances of the four vaccines being used in our country,” Dr Be-nazir said.

Conducting experiment

Prof Dr Mohammed Atiqur Rahman, a respiratory medicine expert at Bangabandhu Sheikh Mujib Medical University (BSMMU), also said that Bangladesh should not go for booster doses before completing the current vaccination drive.

“But we can experimentally give it to our frontline workers who received the two shots of the AstraZeneca vaccine around nine months back at the initial stage of the inoculation programme. Before that we have to check the persisting level of antibodies in them,” he said.

Dr Atiq said there are two main things to consider -- the adverse reactions and whether the booster shot should be the same or a different vaccine. “That’s why we need to apply the booster shots of different vaccines on the frontline workers to know their comparative results and side-effects.”

“I hope we’ll get more effective oral drugs to deal with Covid in a couple of years."

Intensifying vaccination drive

Public health expert Dr Abu Jamil Faisel, a member of the DGHS’ Covid-19 Public Health Advisory Committee, also thinks that time has not yet come for Bangladesh to consider a third shot.

"The World Health Organisation has still not recommended booster doses. So, we should now fully concentrate on bringing most of our people under the vaccination coverage," he said.