NOVEMBER 24 ― The minister and director-general of our Ministry of Health (MoH) are both warning us that there may be new a wave of Covid-19 infection if the situation gets worse. Clinicians treating Covid-19 patients also highlighted that the Covid-19 hospital admissions and intensive care unit (ICU) usage are on the rise. Are they being overly worried and pessimistic of our country’s Covid-19 situation? Why is this happening when our vaccination rate is almost reaching 80 per cent for the whole nation?
Let’s go through some of the statistics related to Covid-19. The R naught (represents then number of people that an infected person transmits that disease to) for Covid-19 was 0.87 on October 22, 2021, and it was fluctuating below 1.0 until November 11, 2021. Since then, the R naught values have increased and fluctuating between 1.0 to 1.05, with the latest value at 1.0 on November 22, 2021. An R naught of less than 1.0 is required if we want the total infection to be reduced.
The lowest number of daily cases of 4,343 was achieved on November 7, 2021, but there was no further improvement. Instead, the total daily cases had increased to 6380 on November 18, 2021, and fluctuating between 4,000 plus to 6,000 plus since then. Concurrently, the ICU usage in some states ie. Selangor, Kuala Lumpur, Kelantan, Penang and Putrajaya is more than 75 per cent.
Despite the total population’s full vaccination rate has achieved 76.6 per cent (October 23, 2021), we noticed that our Covid situation is not further improved. Why did this happen? First, with the opening of most sectors and interstate travel allowed, this has increased the mobility of our people. When mobility is increased and if there is poor compliance of standard operating procedures for Covid-19 among some people, this will incur transmission among unvaccinated as well as vaccinated people. We are also well aware that vaccination is not 100 per cent effective in the prevention of transmission, but just effective in the prevention of severe Covid, hospitalisation and death.
This situation may become more serious when evidences show that the vaccine effectiveness will wane over time. From the latest data from the RECoVaM (The Real World Evaluation of Covid-19 Vaccines under the Malaysia National Covid-19 Immunisation Programme), the vaccine effectiveness in the prevention of Covid-19 infection reduced to 68 per cent (Pfizer) and 28 per cent (Sinovac) in three to five months after full vaccination. The prevention of ICU admission among individuals vaccinated with Pfizer and Sinovac vaccines at three to five months was 79 per cent and 28 per cent respectively, while the prevention of death for both vaccines was 91 per cent and 76 per cent respectively. These evidences showed that vaccine effectiveness wane over time, with the waning effect from Sinovac vaccine was below 50 per cent, a cut off value acceptable for vaccine effectiveness.
Concurrently, the analysis on deaths among patients taking different vaccines showed that there were 6.0 deaths per one million population for AstraZeneca vaccine, 9.8 deaths per one million population for Pfizer vaccine and 34 deaths per one million population for Sinovac vaccine. All the above data showed that with the waning effect of vaccine, especially Sinovac vaccine that wanes faster, caused higher deaths compared to other vaccines. Of course, the findings may be influenced by the age of these patients who are mostly from the senior citizen group.
That is why the Ministry of Health are aggressively pushing for booster doses among the senior citizens and high-risk groups with comorbidities who took the Sinovac vaccines. However, the response for booster dose is poor due to the reason that only Pfizer vaccine is offered as booster currently. There are worries on the adverse side effects of taking the booster dose that is different from the first two doses. Mix and match vaccination especially for booster dose has been practiced in many countries. For example, Indonesia, Singapore and Chile mixed Sinovac with Pfizer; while Thailand and Cambodia mixed Sinovac with AstraZeneca. The Western countries have also been mixing their available vaccines (Pfizer, AstraZeneca and Moderna). There have been no known severe side effects reported from these countries.
The main reason for mixing Sinovac with other vaccines is because the mixing with Pfizer or AstraZeneca will produce up to 94 to 95 per cent vaccine effectiveness, while using Sinovac as the booster will only provide 75 per cent vaccine effectiveness. It is unfortunate that there is a lot of unverified information against mixing of Sinovac with Pfizer being circulated in the social media. We are aware that many individuals are influenced and declined the Pfizer vaccine as booster.
This has jeopardised the MoH’s efforts of providing additional protection to these groups. Our country cannot afford to have another lock down when our health care system is over burdened with more severe Covid infections that require ICU usage. We should take note of new waves happening in some European countries (ie. Austria, Netherlands, Germany) that have to reinforce a lock down (Austria and Netherlands) or contemplate lock down (Germany). Their people have been complaining that their governments had not taken prevention measures early enough to prevent the spike in Covid-19 infections that caused lock down to be implemented.
Our people should value the freedom we enjoy currently, comply with SOPs during work or leisure, go for booster dose when called. Do not wait for vaccine brand which is unavailable, go for the first one being offered to get yourself and your love ones protected. We hope the Ministry of Health can also expedite the inclusion of Sinovac vaccine in the national immunisation programme. We as Malaysians should do our parts so that the Covid situation is well controlled and our country can move on to improve the economic situation.
* Professor Dr Moy Foong Ming is a Professor of Epidemiology at the Department of Social and Preventive Medicine, Faculty of Medicine, University of Malaya.
