CITF endorses boosters for all adults, allows choice for Sinovac shot

The Technical Working Committee under the Covid-19 Immunisation Taskforce – Boosters (CITF-B) has expanded the eligibility of Covid-19 booster shots to everyone above the age of 18, though certain groups such as senior citizens will still have priority for appointments.

In addition, it has backed down from the earlier proposal to use Pfizer’s vaccines as the “default” option. Instead, it says people who previously completed their vaccination with the Sinovac vaccine will be allowed to choose the Sinovac shot for their third dose.

In a statement today, Health Minister Khairy Jamaluddin said the committee recommends using the Pfizer vaccine as a booster shot for Sinovac recipients of all ages three months after their second dose. For those above 50 years old, the AstraZeneca vaccine may be used instead.

For those unable to receive the Pfizer or AstraZeneca boosters, the Sinovac vaccine can be used as a booster instead.

“For those who choose the CoronaVac (Sinovac) vaccine as a booster, they can inform the vaccine administration centre (PPV) to get the vaccine.

“However, the Technical Working Committee still recommends the Comirnaty (Pfizer) or AstraZeneca vaccine as a booster shot,” he said in a statement today.

Pfizer mix-and-match shot favoured for robust immunity

Previously, Clinical Research director Dr Kalaiarasu Periasamy said the committee had proposed using the Pfizer vaccine by default as a booster shot while reserving the Sinovac vaccine for those with known allergies or other contraindications to the Pfizer vaccine.

This is because heterologous vaccination following the Sinovac shot is found to produce a robust immune response that led to higher vaccine effectiveness.

Citing a study in Chile, he said using a homologous Sinovac booster increased vaccine effectiveness against Covid-19 infection from 56 percent to 80 percent, whereas heterologous boosters with the Pfizer or AstraZeneca vaccine increased this to 90 percent and 93 percent respectively.

Against hospitalisation, the Sinovac booster increased effectiveness from 84 percent to 88 percent, compared to 87 percent for Pfizer and 96 percent for AstraZeneca.

Recipients of the Sinopharm vaccine - which is also an inactivated virus vaccine like the Sinovac vaccine - are also eligible for a booster shot three months after their second dose.

Recipients of regardless of age are recommended to get the Pfizer vaccine as a booster, while those above 50 years old may also get the AstraZeneca vaccine.

The CITF-B recommendations today follow Drug Control Authority’s conditional approval to use the Pfizer vaccine as a booster shot on Oct 8, and similar approvals for the Sinovac and AstraZeneca vaccines on Nov 17.

Recommendations for Pfizer, AstraZeneca, and the rest

Meanwhile, for those who previously received the AstraZeneca vaccine, they are recommended to get the same vaccine as the third dose regardless of age. Those who received two doses of the AstraZeneca vaccine for their primary vaccination series are eligible for a booster six months after their second dose.

“However, the Comirnaty (Pfizer) vaccine can also be used,” Khairy said.

Those who previously received the Pfizer, Moderna, or CanSino vaccine are eligible for their booster shots six months after completing their vaccination, while those who got the Janssen (Johnson & Johnson) vaccine are eligible after just two months.

They are recommended to get the Pfizer vaccine as booster regardless of their age, while those above 50 years old may also get the AstraZeneca vaccine.

The rationale for limiting AstraZeneca boosters to people above 50 years old - except for people who already received the same vaccine before - is not explained in Khairy’s statement.

However, the AstraZeneca vaccine is linked to cases of very rare blood clotting disorder known as thrombosis with thrombocytopenia syndrome (TTS), which has led some countries to discontinue its use or limit it to older people where the risk of developing TTS is lower.

In an AstraZeneca-backed study published in The Lancet, it was reported that the reporting rate of TTS was 8.1 cases per million people receiving the first dose.

However, it noted that there is no increase seen among people receiving their subsequent AstraZeneca doses. The reporting rate of TTS in this group is only 2.3 cases per million people getting the second dose, which is no different for unvaccinated people.

Booster priorities

According to Khairy, the booster roll-out will be expanded to all adults using the “age step-down approach”, after previously prioritising people above 40 years old and any adults who have co-morbidities.

People with co-morbidities will continue to be prioritised, along with frontliners, pregnant women, and people who require a booster shot for overseas travel.

The boosters will be given and private medical practices and off-site medical facilities, as well as select government clinics, hospitals, and outreach programs.

A list of participating healthcare facilities is available from the Health Ministry’s website and ProtectHealth Corporation’s website.

“Appointment dates for booster shots for eligible individuals will be given through the MySejahtera app, or recipients can apply to be on a waiting list to get an appointment at selected public and private healthcare facilities,” he said.

Registration for the waiting list had opened on Monday. Successful registration will be notified when a vaccination appointment becomes available due to a cancellation or no-show.

ProtectHealth has urged people to register at only one vaccination centre to avoid confusion.

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