KUALA LUMPUR, Oct 13 — The World Health Organization’s (WHO) Strategic Advisory Group of Experts on Immunisation (SAGE) has recommended an extra Covid-19 vaccine shot for people aged 60 and above who were inoculated with Sinovac or Sinopharm.
The advisory group also said a third jab should be given to moderately and severely immunocompromised people vaccinated with any WHO-approved Covid-19 vaccine.
Data gathered by SAGE showed that people in both groups were at higher risk of breakthrough infections after standard immunisation, which involves two doses for the Chinese Sinovac and Sinopharm vaccines. Immunocompromised people in this group largely include cancer or other patients undergoing treatments that suppress their immune systems.
The group noted that it was not recommending a booster shot, which is an additional shot given after a full primary course to address waning efficacy or the impact of variants. They are recommending it to be given instead as part of “an extended primary series” for these groups who were not mounting a sufficient immune response with two doses.
“There is clearly a public health call for action, and we know that the administration of a third dose can augment the immune response,” said Joachim Hombach, secretary of the independent panel of experts, as quoted by South China Morning Post.
The data examined on Sinovac and Sinopharm’s Covid-19 vaccines “clearly showed that in older age groups… the vaccine performs less well after two doses,” Hombach said.
According to SAGE, the recommendation is for a third dose of the same Sinovac or Sinopharm vaccine to be administered, but if supplies are limited, a vaccine dose by another brand could be considered.
“We feel that this recommendation is timely in the sense that we realise it’s going to have implications about the supply for these vaccines, so we would like to make this earlier rather than later,” SAGE chair Alejandro Cravioto said.
Several lower and middle-income countries in Latin America and Southeast Asia have used China’s vaccines, namely Sinovac and Sinopharm, for their national immunisation programmes. In China, several regions have already started to provide booster shots for targeted groups, in particular adults in high-risk jobs.
Sinovac and Sinopharm have been shown to elicit lower immune responses compared with other Covid-19 vaccines approved by the WHO, but they met criteria in clinical trials against symptomatic disease and have been shown to significantly prevent severe disease and death in adults, South China Morning Post reported.
So far, SAGE experts said they did not see a need to recommend a third shot for younger adults based on existing data for these vaccines.
The group will review data relating to the need for booster shots for these or other vaccines at a meeting next month. The WHO has issued a moratorium on booster doses until the end of the year, citing vast inequities in vaccine access.