Novavax’s Nuvaxovid COVID-19 vaccine granted interim authorisation in Singapore

SINGAPORE: The Health Sciences Authority (HSA) has granted interim authorisation for Novavax’s Nuvaxovid COVID-19 vaccine to be used in Singapore, it announced on Monday (Feb 14).

The vaccine was authorised for use in individuals aged 18 and above on Feb 3 this year. The vaccination regimen comprises two doses of 5 micrograms administered three weeks apart.

The first batch of the vaccine is “expected to arrive in Singapore in the next few months”, HSA said. Last June, Health Minister Ong Ye Kung announced that Singapore signed an advance purchase agreement with Novavax in January.

The interim authorisation was granted under the Pandemic Special Access Route (PSAR).

The PSAR allows HSA to grant interim authorisation for critical novel vaccines, medicines and medical devices during a pandemic.

The only COVID-19 vaccines currently approved under PSAR are the mRNA vaccines Pfizer-BioNTech and Moderna, as well as Sinovac's CoronaVac vaccine, an inactive type.

The Sinovac vaccine was originally authorised under a Special Access Route.

“HSA has reviewed that the vaccine meets the quality, safety and efficacy standards, and that the benefits outweigh the risks for the Singapore population," it added.

“Two groups of experts from HSA’s Medicines Advisory Committee and Panel of Infectious Diseases Experts were also consulted and agreed with HSA’s recommendation for PSAR authorisation.”

Novavax's COVID-19 vaccine is a protein-based vaccine candidate engineered from the genetic sequence of the first strain of SARS-CoV-2, the virus that causes COVID-19. 

The vaccine is stored at 2 degrees Celsius to 8 degrees Celsius, enabling the use of existing vaccine supply and cold chain channels, said Novavax previously.

CLINICAL TRIALS

HSA’s clinical review was based on two Phase 3 clinical studies conducted in the United States, Mexico and the United Kingdom, comprising more than 40,000 clinical trial participants aged between 18 and 95, it said.

"The results showed that Nuvaxovid demonstrated a vaccine efficacy of approximately 90 per cent against symptomatic COVID-19 and 100 per cent in preventing severe COVID-19," HSA said.

"It showed consistent efficacy against the Alpha variant, but there was no data on the Delta and Omicron variants, as these variants were not prevalent at the time Novavax conducted the clinical trials."

Based on the data from the clinical trials to date, the safety profile of Nuvaxovid was "generally consistent with other registered vaccines in Singapore", said the authority.

Common side effects that recipients may experience include injection site pain and/or tenderness, fatigue, headache and muscle pain.

"These symptoms are reactions generally associated with vaccinations and expected as part of the body’s natural response to build immunity against COVID-19. These side effects usually resolve on their own within a few days," said HSA.

As with all vaccines, there will "always be a small proportion of susceptible persons" who may experience severe allergic reactions upon vaccination, including those with a history of anaphylaxis, said HSA.

Anaphylaxis is the rapid onset of severe allergic reactions.

"In such cases, immediate medical attention should be sought. Persons who develop anaphylaxis to the first dose of Nuvaxovid should not be given the second dose," added the authority.

"Safety and efficacy data in severely immunocompromised persons and those under the age of 18 are not available yet. Hence, no recommendation can be made for the use of the vaccine in these individuals."

As a condition for interim authorisation under the PSAR, Novavax is required to monitor the longer-term efficacy of Nuvaxovid to determine the duration of protection against COVID-19.

It is also required to follow up on the safety of the vaccine over a longer period to determine its overall safety profile, including in "special populations" such as immunocompromised people, pregnant women and children.

"HSA will actively review evolving vaccine effectiveness and safety data to ensure that the benefits of the vaccine continue to outweigh the known risks," it said.

"PSAR interim authorisation may be terminated at any time; for example, if new data suggests that the benefits no longer outweigh the risks. To obtain full registration, Novavax will need to submit the complete dataset based on prevailing international standards."

Novavax filed for interim authorisation of its COVID-19 vaccine under the PSAR in November. 

Editor’s note: An earlier version of this article said that Sinopharm’s Sinovac vaccine was approved under PSAR. It was, in fact, Sinovac’s CoronaVac vaccine. We apologise for the error.