KUALA LUMPUR: The scientific community is urging the government to release data on Covid-19 infections among the fully vaccinated.
This, they believe, can help them gauge the effectiveness of various vaccines as well as map a better vaccination and response plan.
Their call comes on the heels of a recent Covid-19 outbreak involving 204 out of 453 medical personnel and volunteers based at the Ideal Convention Centre vaccination centre (PPV) in Shah Alam.
The incident forced the PPV to close down for a day on July 13.
Former Health deputy director-general Datuk Dr Christopher Lee said this was worrying as nearly 88 per cent of the workers in question were already vaccinated.
"To allay any anxiety, it would be good to see how many staff were fully vaccinated, what vaccination was given and the infection control measures (taken) on-site," he posted in a tweet.
Epidemiologist Datuk Dr Awang Bulgiba Awang Mahmud said there was insufficient data available to gauge the impact of the Malaysian vaccination drive.
He said data on Covid-19 infections, especially those which break through vaccination shields, were crucial to assess the impact of the inoculation drive amid emerging variants.
"I urge the Health Ministry to release this alongside the data on (antibody profiles) of those who are unvaccinated.
"I'm worried that some of the vaccines in our portfolio might not be as effective against the Beta and Delta virus variants," he said.
Health director-general Tan Sri Dr Noor Hisham Abdullah said only 1.26 per cent, or 3,106 of the 245,932 health workers who had mostly received Pfizer vaccines, were infected post-vaccination.
He also reported that most ofthem had only mild symptoms or no signs of the illness.
However, the impact of the Covid-19 Delta variant on Indonesia and Thailand has led to growing concern.
Active Covid-19 cases in Thailand have crossed the 100,000- mark after several days of 9,000 new daily infections.
The spread of Covid-19 and double-variant infections on vaccinated healthcare workers, among others, have also prompted Thai authorities to make the unprecedented call of mixing vaccines despite the World Health Organisation's caution.
Dr Awang Bulgiba, who chairs the Independent Covid-19 Vaccination Advisory Committee, said while the Health Ministry's genomic surveillance found that Beta was the predominant variant in Malaysia, accounting for 195 of the 273 infections involving variants of concern (VOC) as of July 13, the Delta, which ranked second with 67 cases, could not be dismissed.
He also reported that most ofthem had only mild symptoms or no signs of the illness.
He said the variant had a track record of rapidly displacing other virus strains based on the UK's experience.
He said Malaysia's limited capacity at genomic sequencing could also mean that the variant had already displaced the Beta variant and was driving the jump in community infections.
"To make matters worse, the recent emergence of the Lambda variant is also troubling."
He said Malaysia needed a Voluntary Vaccination Registry where it could study antibody levels, break through infection rates, mix and match vaccines, B-and T-cell immunity as well as rare adverse reactions to inoculations.
He said the registry would entail having blood samples extracted and analysed from participating volunteers pre- and post-vaccination.
The process would be repeated periodically over some years to determine antibody levels of the volunteers, who would also be medically examined by officers operating the registry.
The facility, he said, could either be run by the government, or universities, or even a hybrid of the entities.
Dr Awang Bulgiba said that mixing and matching vaccines or boosters could be done via the registry. He said current clinical studies have been limited to AstraZeneca, Pfizer, Moderna and Novavax.
He said vaccines such as Sinovac, CanSino and Johnson and Johnson that were also in Malaysia's portfolio warranted similar research.
His statement comes on the back of the findings by Thailand's Thammasat University that antibody levels in people fully vaccinated with the Sinovac vaccine declined by half every 40 days.
Those who received a second dose more than 60 days after their first dose had on average lower levels of antibodies than those who got the second dose in less than 60 days.
It also said that vaccine potency within 60 days of the second dose was between 60 per cent and 70 per cent against the original strain.
The potency against the original strain, however, declined to around 50 per cent in those receiving the second shot, for over 60 days.
However, no data was available on the potency of two doses of the Sinovac vaccine against variants, especially on the Alpha and Delta strains.
The Bangkok Post in its report said that the overall level of artificial immunity was likely to drop in older people.
It added that those aged over 40 showed lower antibody levels than those of younger people.