Expert Committee On COVID-19 Vaccination: Updated Recommendation On Use Of COVID-19 Vaccines

1.      The Expert Committee on COVID-19 Vaccination notes the interim authorisation of the Sinovac-CoronaVac COVID-19 vaccine by the Health Sciences Authority (HSA) under the Pandemic Special Access Route (PSAR), for use in Singapore in individuals aged 18 years and above to prevent COVID-19.

2.      The Expert Committee has independently reviewed the Sinovac-CoronaVac (COVID-19) vaccine’s safety and efficacy data for different population segments in Singapore and has been briefed by HSA on its full range of considerations in granting interim authorisation.

3.      The safety profile of the Sinovac-CoronaVac vaccine was observed to be consistent with other registered vaccines against other diseases.

4.      In its key Phase III clinical trial study in Brazil, two doses of the Sinovac-CoronaVac vaccine demonstrated a vaccine efficacy of 51% against symptomatic infection by earlier SAR-CoV-2 strains prior to the Delta variant, with a higher rate of protection against severe disease. However, varying effectiveness was observed in a range of different studies. There is also no comprehensive data on its protection against the Delta variant. Furthermore, antibody levels after vaccination were low and declined rapidly within three to six months after completion the 2nd dose returning to pre-vaccination levels by six months.

5.      While Sinovac did not apply to HSA for PSAR authorisation of a 3-dose regimen for its Sinovac-CoronaVac vaccine, there is evidence that a third dose of the vaccine is needed at three to six months after the second dose to raise antibody levels. This is consistent with the World Health Organisation Strategic Advisory Group of Experts (SAGE) recommendation of a third dose for those aged 60 and above for the primary vaccination series.

6.      The Expert Committee also notes that as at 23 October 2021, more than 84% of our total population has received at least one dose of the PSAR-authorised mRNA vaccines which have been the mainstay of our National Vaccination Programme.

7.      In view of the lower efficacy of the Sinovac-CoronaVac vaccine as compared to the PSAR-authorised mRNA vaccines and the lack of data on the efficacy of the Sinovac-CoronaVac vaccine against the Delta variant, the Expert Committee recommends that persons who are unable to complete the full two-dose regime of the PSAR-authorised mRNA vaccines, due to valid medical reasons, should receive the Sinovac-CoronaVac vaccine. This includes those who have taken their first dose of one of the PSAR-authorised mRNA vaccines and developed myocarditis or allergies to the mRNA vaccines, as well as those who have a past history of allergy to a component in the mRNA vaccines.

8.      The PSAR-authorised mRNA vaccines remain the recommended COVID-19 vaccines for all persons who are eligible, given the higher vaccine effectiveness against infection and severe disease, including against the Delta variant. Taking the Sinovac-CoronaVac vaccine will allow those who are medically unable to complete their primary vaccination using mRNA vaccines, to be protected against COVID-19, and to be considered fully vaccinated.

9.      Given the circumstances aforementioned, persons of all ages who are eligible to receive the Sinovac-CoronaVac vaccine are recommended to receive three doses of the vaccine as their primary vaccination series. The second dose should be taken 28 days after the first dose, while the third dose should be taken 90 days after the second dose. The recommended timing of the third dose corresponds to when antibody levels are known to have declined. Persons who have received two doses of the Sinovac-CoronaVac vaccine but are able to receive the PSAR mRNA vaccines, are strongly recommended to take one of the mRNA vaccines for the third dose of their primary vaccination series. Please refer to the Annex for further details on the recommended use of the vaccine under different circumstances.

10.     The Sinovac-CoronaVac vaccine is not recommended for use as a booster vaccination, except in persons who are unable – for medical reasons – to receive a third dose of the mRNA vaccine. Persons who have completed two doses of the mRNA vaccine without allergies or severe adverse events, are recommended to receive an mRNA vaccine instead of the Sinovac-Coronavac vaccine, if they are eligible for a booster.

11.     There has been similar evidence that antibody levels from the Sinopharm BIBP vaccine also decline after two doses, and a third dose increases this substantially. The Expert Committee notes that some individuals have opted for Sinopharm BIBP under the Special Access Route (SAR) as their primary series vaccination despite the PSAR mRNA vaccines being strongly recommended for them. They are strongly recommended to take one of the PSAR mRNA vaccines for the third dose of their primary series vaccination. If they decline, a third dose of the Sinopharm BIBP vaccine, is recommended, to be given at three months after the second dose to complete their primary vaccination series.

12.     Separately, local and international safety data now indicate more clearly that persons with severe allergies to non-COVID-19 vaccines can be safely vaccinated with mRNA vaccines. These persons were previously required to undergo a review by a specialist before vaccination. Given the greater assurance of safety that we now have, based on global and local data, persons with severe allergies to other non-COVID-19 vaccines can now receive the mRNA vaccine without being reviewed by a specialist. Persons with documented allergy to PEG, which is a component of mRNA vaccines, continue to be ineligible for the mRNA vaccines.

13.     The Expert Committee will continue to monitor and review the use of COVID-19 vaccines in Singapore as more data becomes available over time, and update our recommendations as necessary. A high local vaccination coverage is key to protect ourselves from COVID-19, and we encourage all medically eligible persons to be vaccinated.

EXPERT COMMITTEE ON COVID-19 VACCINATION
23 OCTOBER 2021