KUALA LUMPUR: The proposal to have an immunity passport needs greater consultation as there are many issues that need to be considered before it can be rolled out, medical experts said.
The government, they said, should have a clear plan and principled rationale about any new privilege it was looking to extend to those who had been inoculated against Covid-19.
This was to ensure that it did not harm public health response to the pandemic and would not be deemed "unfair treatment" by certain parties, besides avoiding possible challenges in its implementation.
Epidemiologist Datuk Dr Awang Bulgiba Awang Mahmud said although an immunity passport appeared to support public health measures to combat the pandemic, it needed to be thought through properly.
This, he said, included factoring in children who would be at a disadvantage as they could not be vaccinated due to a lack of safety data from clinical trials.
"There will also be people whose turn to be vaccinated has not yet come or those who cannot be vaccinated for medical reasons, like those undergoing treatment for major illnesses.
"This would just be for local travel."
The head of the Independent Covid-19 Vaccination Advisory Committee (ICVAC) under the Science, Technology and Innovation Ministry said for international travel, the immunity passport involved sovereignty, rights of nations and individual rights.
There were also questions on the feasibility of establishing such a system, its trustworthiness and effectiveness in the face of virus mutations, he said.
"The variability in vaccine effectiveness and whether all vaccines can be recognised as being equivalent in effectiveness will also come into play.
"Reciprocal recognition of regulatory approvals from different countries will be needed, which may prove to be a stumbling block," he told the New Straits Times.
Dr Awang said an immunity passport would disadvantage nations that had not been able to secure sufficient vaccines for their population as their citizens would not be able to be part of this system.
Until all nations vaccinated their populations, an immunity passport might be viewed as discriminatory and hinder the growth and recovery of poorer nations, as their unvaccinated citizens might be prevented from travelling, he said.
"It is best to rely on the evidence, but the data must be trustworthy, and presented properly, like incidences of new infections and evidence of transmission protection."
He said Malaysia needed to establish whether immunity obtained via vaccination prevented transmission, whether the immunity was long-lasting and protected against newer variants, or consider changes in quarantine requirements and the standard operating procedures.
"The usual passive surveillance following vaccination is likely to underestimate true disease rates and transmission protection.
"ICVAC has recommended that the government establish a voluntary Covid-19 Vaccination Registry to follow up on 50,000 vaccinated people for the next two years. Combining the evidence from passive and active surveillance will be the best way of establishing this evidence.
"Once we establish that real incidences are sustainably low and transmission protection has been proven (via epidemiological studies), then some travel restrictions can be lifted."
He said the travel restrictions (for inter-district and interstate movement) could buy time for Malaysians to form herd immunity against Covid-19.
"It would take time for people to build up immunity against the virus as most of the Covid-19 vaccines require two doses.
"Assuming that a person is given a two-dose vaccine, which is spaced three weeks apart and the body requires two weeks to build immunity to resist infection, that would require a minimum of five weeks. We need to vaccinate a large number of people to achieve a sustained decline in new infections, and this will take some months."
He said no country had yet to achieve herd immunity while actively vaccinating their population, including the United States and the United Kingdom, and the countries had imposed travel restrictions.
He said it would be prudent not to rush the decision until there was evidence of increasing immunity, adding that travel restrictions could be considered part of non-pharmaceutical interventions (NPIs), and must continue in some form until there was a sustained decline in new infections.
Other forms of NPIs, which had been promoted largely by authorities, were the wearing of masks, physical distancing and practising good hygiene.
Manipal University College Malaysia community and occupational medicine Professor Dr G. Jayakumar said immunity passports might allow vaccinated and immune people to follow less stringent requirements on physical distancing.
"They may be exempted from quarantine requirements, allowed to travel as well as return to work, care for those at risk, visit friends and relatives, or undertake activities that expose them to the virus.
"However, whether this strategy should be pursued depends on scientific, social and ethical reasoning."
Dr Jayakumar said the government should focus on high-risk communities, like foreign workers, prisoners and senior citizens, to break the chain of transmission.
Associate Professor Dr Malina Osman, an epidemiologist and biostatistician from Universiti Putra Malaysia, said the easing of travel restrictions should not be based on the proportion of vaccination coverage.
"Travelling can be allowed once active cases are within the two-digit range.
"According to field observations, there is good indication of compliance with the SOP by the public as well as the use of the MySejahtera application to re-cord their travels.
"With the increased penalty of RM10,000 for individuals and RM50,000 for companies for SOP violations, hopefully, we can deter people from breaking the regulations."