KUALA LUMPUR, Jan 12 – World Health Organization (WHO) experts on Tuesday said repeating booster doses of the original Covid-19 vaccines is not a viable strategy against new coronavirus variants and that current vaccines need to be reworked to ensure they are effective.
The WHO expert group, created to assess the performance of Covid-19 vaccines, said providing additional doses of existing vaccines as a protection against new coronavirus variants as they emerge was not an effective way to deal with the pandemic.
“A vaccination strategy based on repeated booster doses of the original vaccine composition is unlikely to be appropriate or sustainable,” the WHO Technical Advisory Group on Covid-19 Vaccine Composition (TAG-Co-VAC) said in a statement.
The group said the composition of current Covid-19 vaccines need to be updated to not only protect people who contract Covid against serious illness but also better prevent people from infection against Omicron and future variants.
“Covid-19 vaccines that have high impact on prevention of infection and transmission, in addition to the prevention of severe disease and death, are needed and should be developed,” TAG-Co-VAC said.
“Covid-19 vaccines need to elicit immune responses that are broad, strong, and long-lasting in order to reduce the need for successive booster doses,” it added.
However, the statement fell short of calling for an Omicron-specific vaccine at this stage, saying more research was needed and urging manufacturers to share data.
It said that an updated vaccine could be aimed specifically at the dominant variant, or be a “multivalent vaccine” that could fight several variants at once.
Some vaccine manufacturers are already in the process of developing next-generation Covid-19 vaccines targeting Omicron.
Pfizer chief executive Albert Bourla, on Monday, said the company is already manufacturing doses of an Omicron vaccine that will be ready in March.
Moderna is also working on an Omicron-specific booster shot that could be ready in the autumn of 2022. Its CEO Stephane Bancel said the booster dose will enter clinical trials soon.
WHO incident manager Abdi Mahamud was reported as saying last week that the issue of vaccine composition required “global coordination”, and should not be left to the commercial sector to decide alone.