Double jabs may be ineffective against Omicron without booster

New York – A new study studies suggests double covid vaccines may be ineffective against the Omicron variant without a booster shot.

Three covid vaccines appear to be significantly less protective against the newly-detected Omicron strain in laboratory testing, but a booster dose probably restores most of the protection, according to a study just released.

The study from researchers at Massachusetts General Hospital (MGH), Harvard and MIT tested blood from people who received the Moderna, Johnson & Johnson and Pfizer/BioNTech vaccines against a pseudo-virus engineered to resemble the Omicron variant.

The researchers found low to absent antibody neutralisation of the variant from the regular regimens of all three vaccines - two shots of the Moderna or Pfizer/BioNTech vaccines or one of J&J's single-dose vaccine.

But the blood from recent recipients of an additional booster dose exhibited potent neutralisation of the variant, the research showed.

The scientists suggested Omicron is more infectious than previous variants of concern and about twice as transmissible as the Delta variant, which may soon be overtaken by Omicron.

The results are in line with other studies recently published. Researchers at the University of Oxford found the two-dose vaccine regimens do not induce enough neutralising antibodies against the new variant.

Confirmed cases of covid have passed 271.5 million globally, according to Johns Hopkins University. The number of confirmed deaths has passed 5.32 million. More than 8.55 billion vaccination doses have been administered globally, according to Our World in Data.

Meanwhile, Pfizer and BioNtech are set to displace AstraZeneca as the main suppliers of covid vaccines to the global covax programme at the start of 2022, a shift that shows the increasing importance of their shot for poorer states.

The expected change comes with headaches for receiving countries that lack sufficient cold storage capacity to handle the Pfizer vaccine, and amid risks of a shortage of syringes needed to administer that shot.