Some areas are showing Covid-19 vaccination rates exceeding 100 percent due to outdated census, said Health Minister Khairy Jamaluddin.
The health authority, he said, assumes that its Covid-19 vaccination targets are all underestimated because of this and undocumented migrants.
"We assume that the targets are all underestimated because the Statistics Department could not conduct a census last year. So we do not know how deep the black hole is.
"What we are seeing in Kuala Lumpur and the Klang Valley today - where numbers of those vaccinated have exceeded 100 percent of the population - was because, firstly, the foreigners who are not documented, and secondly, underestimation of statistics because of census limitation," he told the media during an interview session on Friday.
Khairy (above) was answering a query on why the ongoing National Covid-19 Immunisation Programme (NIP) saw vaccination rates in some areas beyond 100 percent.
When the country embarked on a mass inoculation exercise in February, Putrajaya aimed for herd immunity by getting at least 80 percent of the country's population vaccinated against Covid-19. Malaysia's population is estimated to be 32.7 million as of this year.
According to statistics issued by the health authority, as of Sept 3, Labuan recorded 102.3 percent of its adult population received at least one dose of the Covid-19 vaccine, while the Klang Valley recorded 112.2 percent.
Khairy said another contributing factor was a transient population, where some areas are seeing fewer people due to their residents moving out, while others have it the other way around.
"People have moved to the Klang Valley recently and it is not reflected in the statistics.
"There are also some districts in the Klang Valley, where statistics show that only 80 percent of the population has been vaccinated so far. However, checks revealed that there were no more people left unvaccinated there.
"At other districts, we are seeing vaccination rates going up to 120 percent, but we are still vaccinating. So we can only assume that migration is occurring," he added.
In the absence of a real denominator, the Health Ministry has to depend on the official statistics for its planning, Khairy said.
However, he stressed that it does not mean they would not vaccinate above and beyond the official number.
"I need to have the denominator as a target. I cannot just pluck the denominator from the air and say that the population is actually 35 million and not 32 million.
"But we are confident that we have enough vaccine supply to cover the so-called population underestimation," he added.